Risk Of Grade II-IV aGVHD Research Articles

Impact of Donor Statin Treatment on Graft-versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation

Some retrospective studies have suggested that long-term donor statin use may protect against graft-versus-host disease (GVHD) in patients receiving cyclosporine (CSP)-based immunosuppression after allogeneic hematopoietic cell transplantation (HCT), but prospective studies of short-term treatment of donors with statin have shown conflicting results. We conducted 2 consecutive prospective clinical trials to assess whether donor statin treatment was associated with protection against severe acute GVHD (aGVHD). In a single-arm phase II trial (study 1), we evaluated whether short-term statin treatment of HLA-matched related donors for 14 days before HCT prevented grade III-IV aGVHD. In a prospective observational cohort study (study 2), we evaluated whether longer-term (>14 days) donor statin use was required for GVHD-protective effects. Study 1 was terminated after 6 of the 35 recipients (17%) developed grade III-IV GVHD. For study 2, we identified 135 patients whose unrelated donors had received long-term treatment with statins up to the time of HCT and 4942 patients whose donors had not received long-term statin treatment. The adjusted odds ratio for grade III-IV aGVHD (statin versus no statin) was .83 (95% confidence interval [CI], .46 to 1.50; P=.54). Multivariable analysis showed no statistically significant differences between the 2 groups in the risk of grade II-IV aGVHD, chronic GVHD, nonrelapse mortality, recurrent malignancy, or overall mortality. Among patients receiving CSP-based immunosuppression, including 35 with donors receiving long-term statin treatment and 973 with donors who did not receive statins, the adjusted odds ratio of grade III-IV aGVHD was .30 (95% CI, .07 to 1.35; P=.12). In study 1, short-term statin treatment of donors was ineffective in preventing grade III-IV GVHD. In study 2, in the prespecified subgroup of recipients given CSP-based immunosuppression, nondefinitive evidence suggested that donor statin use was associated with a reduced risk of severe aGVHD.

HLA B-Leader Mismatch Is Associated with Poor Outcomes in NIMA/NIPA Mismatched Haploidentical Sibling Donor HCT

Background: Sibling haplo donors can be broadly categorized as non-inherited maternal (NIMA) or paternal (NIPA) antigen mismatched based on the non-shared haplotype with the recipient. Older studies with non-PTCy prophylaxis suggested a benefit of NIMA-mismatched over NIPA-mismatched donors, but the same has not been studied with PTCy prophylaxis, especially in the context of increasing recognition of the impact of specific loci HLA-mismatches in haplo HCT, such as the B-leader, which is a leader peptide that is preferentially bound by HLA-E, the ligand for natural killer (NK) receptor NKG2. Objective: To compare the outcomes of NIMA-vs NIPA-mismatched haplo sibling donors and specific loci HLA-mismatches in the setting of T-cell replete HCT with PTCy prophylaxis. Results: We included 57 patients: 29 were NIMA-mismatched and 28 were NIPA-mismatched. Median age at HCT (31 yrs vs 37 yrs, p=0.1) and donor age (32 yrs vs 41 yrs, p=0.1) were similar in both groups. Most received RIC (72% vs 68%, p=0.5), BM graft (79% vs 82%, p=0.8), had HCT-CI >3 (55% vs 54%, p=0.9) and low/intermediate DRI (62% vs 54%, p=0.4) and were ABO matched (65% vs 71%, p=0.8) with the donor. There was a significantly higher proportion of female-donor to male-recipients in the NIMA- than NIPA-mismatched group (55% vs 21%, p=0.005). Specific HLA-mismatches were similar in both groups: B-leader (52% vs 32%, p=0.1), DRB1 (96% each), DQB1 (90% vs 86%, p=0.5), DPB1 (76% vs 79%, p=0.9). The median follow-up was 38 vs 13 months. There were no graft failures, and the median time to engraftment was similar (18 vs 19 days, p=0.3). The cumulative incidence of grade II-IV aGVHD was 31% vs 58%, p=0.04; with no differences in grade III-IV aGVHD (10% vs 11%, p=0.9), cGVHD (11% vs 13%, p=0.9); NRM (28% vs 33%, p=0.9), relapse (21% vs 11%, p=0.4), or OS (54% vs 55%, p=0.8) in NIMA-vs NIPA-mismatched, respectively. In multivariate analysis, NIMA-mismatch (HR 0.1, 95% CI 0.02-0.6, p=0.01 in females) and HLA-A mismatch (HR 0.2, 95% CI 0.1-0.6, p=0.005) were associated with significantly lower risk of grade II-IV aGVHD, while age at HCT >50 yr was high risk for grade II-IV aGVHD (HR 2.7, 95% CI 1.1-6.9, p=0.04). No factor predicted grade III-IV aGVHD, cGVHD or relapse, likely related to a small number of events. B-leader mismatch was associated with high NRM (HR 3.8, 95% CI 1.04-13, p=0.04), poor PFS (HR 2.7, 95% CI 1.1-6.7, p=0.03), and a trend for lower OS (HR 2.4, 95% CI 0.9-6.3, p=0.06). High/very-high DRI was associated with high NRM (HR 4.4, 95% CI 1.5-13, p=0.008) and poor OS (HR 2.6, 95% CI 1-6.6, p=0.05). HCT-CI >3 (HR 2.9, 95% CI 0.9-8.8, p=0.05) was associated with poor OS. Neither NIMA-mismatch nor any other independent HLA-locus mismatches (except B-leader) had an impact on NRM, relapse, PFS, or OS. Conclusion: Among sibling haplo donors, a B-leader matched donor should be prioritized whenever possible. When multiple B-leader matched donors are available, considering the sample size limitations, our data suggest that a donor mismatched at A-locus (lower aGVHD) and/or a NIMA-mismatched donor (lower aGVHD in females) could be selected. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Son Vs Daughter Haploidentical Donor for T Cell-Replete HCT with Ptcy Prophylaxis

Background: A younger haplo donor is usually preferred over an older donor. However, when several donors of similar ages are available, which factors should be prioritized remains a matter of debate. This is a frequent clinical question for older recipients who are undergoing haplo hematopoietic cell transplantation (HCT) from a child donor. Although conventionally a female donor is avoided for a male recipient due to the high risk of graft-versus-host disease (GVHD), this has not been consistently seen in the setting of T cell-replete haploidentical HCT with post-transplant cyclophosphamide (PTCy) prophylaxis. Additionally, there is increasing recognition of the impact of (mis)matches at specific HLA loci with haplo HCT. Whether HLA factors trump non-HLA factors (e.g female-to-male, donor age, relationship), or vice-a-versa, is unclear. As patient and donor ages and relationships are important predictors of outcomes and are very tightly correlated to each other, we studied the effects of HLA and non-HLA factors stratified by donor relationship (son vs daughter). Objective: We sought to compare the outcomes of T-cell replete haplo HCT using a son vs daughter donor with PTCy prophylaxis, after accounting for (mis)matching at individual HLA loci and patient/donor age. Results: We included 298 consecutive patients with a daughter (n=96) vs son (n=202) donor. Median age at HCT (56 yrs vs 58 yrs, p=0.05) and donor age (27 yrs vs 29 yrs, p=0.1) were similar in both groups. Most received RIC (78% vs 76%, p=0.5) and had HCT-CI >3 (52% vs 54%, p=0.6). Fewer patients with a daughter donor received BM graft (56% vs 74%, p=0.002) and had high/very high DRI (20% vs 41%, p<0.001). Most patients were CMV seropositive (83% vs 81%, p=0.09) and ABO matched with donor (60% vs 61%, p=0.9). Significantly more patients with a daughter donor had HLA-C mismatch (97% vs 88%, p=0.01); other mismatches were similar in both groups: A (91% vs 96%, p=0.2), B-leader (43% vs 37%, p=0.6), DRB1 (92% vs 94%, p=0.5), DQB1 (86% vs 90%, p=0.3), DPB1 (76% vs 80%, p=0.4). The median follow-up was 24 vs 27 months. Graft failure occurred in 2% vs 4%, p=0.5; the median time to neutrophil engraftment was similar (20 vs 19 days). The cumulative incidence of grade II-IV aGVHD (39% vs 34%, p=0.5) and grade III-IV aGVHD at day 180 (12% vs 6%, p=0.1), 2-yr cGVHD (18% vs 12%, p=0.4); NRM (28% vs 33%, p=0.5), relapse (24% vs 29%, p=0.4), PFS (47% vs 38%, p=0.2) and OS (50% vs 46%, p=0.4) were similar in daughter vs son, respectively. In multivariate analysis, daughter donors were associated with similar risk of grade II-IV aGVHD (HR 1.2, 95% CI 0.8-1.9, p=0.3), cGVHD (HR 1.03, 95% CI 0.5-2.3, p=0.9), and NRM (HR 0.9, 95% CI 0.6-1.4, p=0.7) as sons. For survival, significant interactions were noted between donor gender and DRI. In patients with low DRI, there was no impact of donor gender, but in patients with high/v high DRI, daughter donors were associated with improved PFS (HR 0.5, 95% CI 0.2-0.9, p=0.03) and OS (HR 0.5, 95% CI 0.3-0.9 p=0.04) as compared to sons. Relapse rate was highest with son-to-mother (HR 1.7, 95% CI 1.02-2.7, p=0.04). PB graft was associated with a significantly higher risk of cGVHD (HR 3.1, 95% CI 1.5-6.4, p=0.003). High/very high DRI was associated with a high risk of relapse (HR 2.4, 95% CI 1.5-3.9, p<0.001). Patient age >50 yrs had high NRM (HR 2.03, 95% CI 1.1-3.7, p=0.02), poor PFS (HR 1.5, 95% CI 1.02-2.3, p=0.04) and OS (HR 1.6, 95% CI 1-2.5, p=0.05). There was no significant impact of specific HLA mismatches on any of the outcomes. Having 3 class II HLA (vs <3) mismatches was associated with a high risk of cGVHD (HR 3.3, 95% CI 1.3-8.7, p=0.01), with no impact on survival. Conclusion: Among child haplo donors, our data suggest that female donors do not result in any inferior outcomes as compared to male donors. A daughter may even be a preferred donor for patients with high/very-high DRI as it conferred survival benefit as compared to a son donor. This may partly be related to a higher risk of relapse seen in son donor to mother recipient. Also, certain HLA mismatches (e.g. B-leader), which have prognostic implications in haplo HCT in general, did not appear to be of significance when accounted for donor relationship and age in patients with a child donor. Further large-scale studies are needed to comprehend these complex immunobiological relationships. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

The impact of pretransplant serum ferritin on haploidentical hematopoietic stem cell transplant for acquired severe aplastic anemia in children and adolescents.

Haploidentical hematopoietic stem cell transplant (haplo-HSCT) provides an important alternative for children and adolescents with acquired severe aplastic anemia (SAA) lacking matched donors. To test whether pretransplant serum ferritin (SF) represents a candidate predictor for survival and a potential biomarker for graft-versus-host disease (GvHD) in pediatric haplo-HSCT, we retrospectively evaluated 147 eligible patients with SAA who underwent haplo-HSCT. The patients were divided into the low-SF group(<1000 ng/mL) and the high-SF group (≥ 1000 ng/mL). We found that SF ≥1000 ng/mL independently increased the risk of grade II-IV aGvHD (HR=2.596; 95% CI, 1.304-5.167, P=0.007) and grade III-IV aGvHD (HR=3.350; 95% CI, 1.162-9.658, P=0.025). Similar probabilities of transplant-related mortality at 100 days were observed in the two groups (6.19 ± 2.45%vs 8.00 ± 3.84%, P=0.168). The two-year overall survival (85.29 ± 3.89%vs 92.00% ± 3.84%, P=0.746) and failure-free survival (83.23% ± 4.08%vs 83.37% ± 6.27%, P=0.915) were comparable. GvHD-/failure-free survival were 60.06 ± 5.10% and 75.56 ± 6.87%, respectively (P=0.056). In conclusion, elevated pretransplant SF level is associated with higher incidences of grade II-IV aGvHD and grade III-IV aGvHD. However, it is not associated with worse survival after haplo-HSCT for children and adolescent patients with SAA.

Donor Killer Immunoglobulin Receptor Gene Content and Ligand Matching and Outcomes of Pediatric Patients with Juvenile Myelomonocytic Leukemia Following Unrelated Donor Transplantation

Natural killer (NK) cell determinants predict relapse-free survival after allogeneic hematopoietic cell transplantation (HCT) for acute myelogenous leukemia, and previous studies have shown a beneficial graft-versus-leukemia effect in patients with juvenile myelomonocytic leukemia (JMML). However, whether NK cell determinants predict protection against relapse for JMML patients undergoing HCT is unknown. Therefore, we investigated NK cell-related donor and recipient immunogenetics as determinants of HCT outcomes in patients with JMML. Patients with JMML (age 0 to <19 years) who underwent a first allogeneic HCT from an unrelated donor between 2000 and 2017 and had available donor samples from the Center for International Blood and Marrow Transplant Research Repository were included. Donor killer immunoglobulin receptor (KIR) typing was performed on pre-HCT samples. The primary endpoint was disease-free survival (DFS); secondary endpoints included relapse, grade II-IV acute graft versus-host-disease (aGVHD), chronic GVHD (cGVHD), GVHD-free relapse-free survival, transplantation-related mortality, and overall survival (OS). Donor KIR models tested included KIR genotype (AA versus Bx), B content (0-1 versus ≥2), centromeric and telomeric region score (AA versus AB versus BB), B content score (best, better, or neutral), composite score (2 versus 3 versus 4), activating KIR content, and the presence of KIR2DS4. Ligand-ligand and KIR-ligand mismatch effects on outcomes were analyzed in HLA-mismatched donors (≤7/8; n=74) only. Univariate analyses were performed for primary and secondary outcomes of interest, with a P value <.05 considered significant. One hundred sixty-five patients (113 males), with a median follow-up of 85 months (range, 6 to 216 months) met the study criteria. Of these, 111 underwent an unrelated donor HCT and 54 underwent a UCB HCT. Almost all (n=161; 98%) received a myeloablative conditioning regimen. After exclusion of recipients of reduced-intensity/nonmyeloablative conditioning regimens and ex vivo T cell-depleted grafts (n=8), there were 42 AA donors and 115 Bx donors, respectively. Three-year DFS, OS, relapse, and GRFS for the entire cohort were 58% (95% confidence interval [CI], 50% to 66%), 67% (95% CI, 59% to 74%), 26% (95% CI, 19% to 33%), and 27% (95% CI, 19% to 35%), respectively. The cumulative incidence of grade II-IV aGVHD at 100 days was 36% (95% CI, 27% to 44%), and that of cGVHD at 1 year was 23% (95% CI, 17% to 30%). There were no differences between AA donors and Bx donors for any recipient survival outcomes. The risk of grade II-IV aGVHD was lower in patients with donors with a B content score of ≥2 (hazard ratio [HR], 0.46; 95% CI, 0.26 to 0.83; P=.01), an activating KIR content score of >3 (HR, 0.52; 95% CI, 0.29 to 0.95; P=.032), centromeric A/B score (HR, 0.57; 95% CI, 033 to 0.98; P=.041), and telomeric A/B score (HR, 0.58; 95% CI, 0.34 to 1.00; P=.048). To our knowledge, this is the first study analyzing the association of NK cell determinants and outcomes in JMML HCT recipients. This study identifies potential benefits of donor KIR-B genotypes in reducing aGVHD. Our findings warrant further study of the role of NK cells in enhancing the graft-versus-leukemia effect via recognition of JMML blasts.

Mesenchymal stem cells enhance the impact of KIR receptor-ligand mismatching on acute graft-versus-host disease following allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia but not in those with acute lymphocytic leukemia.

Killer cell immunoglobulin-like receptor (KIR) receptor-ligand mismatch has been shown to be protective for acute and chronic graft-versus-host disease (aGVHD, cGVHD) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) for acute leukemia. Mesenchymal stem cells (MSC) have been considered as one of the most promising prophylaxis for severe GVHD. However, there are no prospective or retrospective studies determining whether they can work synergistically on GVHD. To investigate the potential influence of KIR matching and MSCs, and their synergism on aGVHD and cGVHD after allo-HSCT in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) patients. Data from 104 patients with AML and 50 patients with ALL treated with allo-HSCT in the transplantation unit were retrospectively analyzed. KIR genotyping was performed by the PCR-SSO method. The amplicons were quantified on the Luminex 200 flow analyzer and analyzed using the Quick-Type for Lifecodes software to generate KIR data. Cox proportional hazards models were used in multivariate analyses. KIR receptor-ligand matching was associated with an increased risk of grade II-IV aGVHD compared to KIR receptor-ligand mismatching (p<0.001) in AML patients, but KIR ligand-mismatching had no significant effect on aGVHD or cGVHD in ALL patients. In contrast, MSCs reduced the incidence of grade II-IV aGVHD in both AML and ALL patients (AML: p=0.006; ALL: p=0.008) regardless of KIR mismatching. The combination of KIR receptor-ligand mismatch and MSC transplantation significantly suppressed grade II-IV aGVHD occurrence in AML patients (p=0.039). In the KIR mismatch group, the incidence of aGVHD was 2.8% in patients receiving MSC compared to 14.6% in those who did not (p=0.047). KIR receptor-ligand mismatch, MSC transplantation and their combined use significantly reduced the risk of aGVHD after allo-HSCT. These data provide a clinically applicable strategy to reduce aGVHD, thus improving allo-HSCT outcome.

Broad-Spectrum Antibiotics and Risk of Graft-versus-Host Disease in Pediatric Patients Undergoing Transplantation for Acute Leukemia: Association of Carbapenem Use with the Risk of Acute Graft-versus-Host Disease

Variation in the gastrointestinal (GI) microbiota after hematopoietic cell transplantation (HCT) has been associated with acute graft-versus-host disease (aGVHD). Because antibiotics induce dysbiosis, we examined the association of broad-spectrum antibiotics with subsequent aGVHD risk in pediatric patients undergoing HCT for acute leukemia. We performed a retrospective analysis in a dataset merged from 2 sources: (1) the Center for International Blood and Marrow Transplant Research, an observational transplantation registry, and (2) the Pediatric Health Information Services, an administrative database from freestanding children's hospitals. We captured exposure to 3 classes of antibiotics used for empiric treatment of febrile neutropenia: (1) broad-spectrum cephalosporins, (2) antipseudomonal penicillins, and (3) carbapenems. The primary outcome was grade II-IV aGVHD; secondary outcomes were grade III-IV aGVHD and lower GI GVHD. The adjusted logistic regression model (full cohort) and time-to-event analysis (subcohort) included transplantation characteristics, GVHD risk factors, and adjunctive antibiotic exposures as covariates. The full cohort included 2550 patients at 36 centers; the subcohort included 1174 patients. In adjusted models, carbapenems were associated with an increased risk of grade II-IV aGVHD in the full cohort (adjusted odds ratio [aOR], 1.24; 95% confidence interval [CI], 1.02 to 1.51) and subcohort (sub hazard ratio [HR], 1.31; 95% CI, 0.99 to 1.72), as well as with an increased risk of grade III-IV aGVHD (subHR, 1.77; 95% CI, 1.25 to 2.52). Early carbapenem exposure (before day 0) especially impacted aGVHD risk. For antipseudomonal penicillins, the associations with aGVHD were in the direction of increased risk but were not statistically significant. There was no identified association between broad-spectrum cephalosporins and aGVHD. Carbapenems, more than other broad-spectrum antibiotics, should be used judiciously in pediatric HCT recipients to minimize aGVHD risk. Further research is needed to clarify the mechanism underlying this association.

Rapid Engraftment, Immune Cell Reconstitution and Sustained Donor Chimerism in Patients Receiving G-CSF Mobilized Peripheral Blood Stem Cells (PB-SC) from Related or Unrelated Donors Undergoing CD34 Enrichment with Mononuclear Cell (T cell) Addback in Children, Adolescents, and Adults with Malignant and Nonmalignant Diseases

Background: Graft versus host disease (GVHD) is a life-threatening complication following allogeneic stem cell transplantation (AlloSCT), which results from allo-reactive donor T-cells reacting against human leukocyte antigen (HLA) disparate host antigens. Despite the use of prophylactic immunosuppresants, 40 to 70 percent of patients undergoing HLA matched related and unrelated transplants will develop grade II-IV acute GVHD (Goker et al, Ex Hem, 2001; Nademanee, Blood, 1995; Rutuu et al, BMT, 1997).CD34+ enrichment of GCSF mobilized peripheral blood stem cells (PBSCs) obtained by apheresis is a method for T-cell depletion to reduce the risk of Grade II-IV aGVHD but unfortunately maybe concomitantly associated with delayed immune reconstitution, increased opportunistic infection and/or malignant relapse. To circumvent these latter complications, we previously demonstrated the results of a CD34+ enrichment with mononuclear cell (MNC) addback fixed at 2x105 CD3/kg of recipient weight in pediatric MUD recipients demonstrating rapid engraftment, robust immune reconstitution, and a low incidence of Grade II-IV aGVHD (Geyer/Cairo, BJH, 2012).More recently, we demonstrated a similar approach in children, adolescents, and young adults with high-risk SCD following familial haploidentical stem cell transplantation resulting in a rapid engraftment, probability of 6.7% of Grade II-IV aGVHD and 90% 1-year OS (Cairo et al, JAMA Peds, 2020). This approach of PBMNC addback with a fixed dose of 2x105 CD3/kg facilitated the infusion of additional NK, NKT, B, DC, DC2 cells at that same time (Chu/Cairo et al, ASH, 2020). Objective: To determine the safety, hematopoietic engraftment, probability of Grade II-IV GVHD following HLA related and unrelated PBSC transplantation following CD34+ enrichment with MNC cell addback (2x105 T-cell/kg fixed dose) in patients with malignant and non-malignant diseases. Design/Methods: Eligible patients were enrolled on study. Patients received individualized conditioning regimens determined by the PI stratified by disease, disease status, and donor source and received CD34+ enriched products processed by using the CliniMACSâ CD34+ Reagent System (Miltenyi Biotec, Bergisch Gladbach, Germany). The CD34+ cell product was either infused or cryopreserved and stored until time of transplantation. A target of 5x106 CD34+/kg recipient weight with a PBMNC fixed dose of 2x105 T cell CD3 dose/kg was infused as we previously demonstrated (Cairo et al, JAMA Peds, 2020). Patients were followed for safety, engraftment, donor chimerism, probability of Grade II-IV aGVHD and chronic GVHD. Results: Thirty-eight patients underwent HSCT with median age of 35.2 years (21 months to 71 years). Patients' disease status was as follows: complete remission (CR) 3 in 1 AML patient, CR2 in 8 AML patients, CR1 in 14 AML patients, CR2 in 4 ALL patients, CR1 in 2 ALL patients, PR in 1 MDS patient, Lymphohistiocytosis (n=1), Macrophage Activating Syndrome (n=1), Diamond Blackfan (n=1), Aplastic Anemia (n=2), Sickle Cell Disease (n=1), 1 CNL patient, CR2 in 1 Non-Hodgkins Lymphoma patient. Sixteen patients received allogeneic 10/10 HLA-matched unrelated donors, 5 from 9/10 HLA-matched unrelated donors, 12 from 6/6 HLA-matched sibling donors, 5 from related haplo donors. PB-HPC products contained 2x105 CD3/kg (±0.25 x 105), and 9.72x106 CD34/kg (±0.97 x106). After CD34 enrichment, the PB-HPC product processed was 76.09% CD34+ (±2.7%) (Fig. 1A) enriched with mean ± SEM log T cell depletion of 4.01 (±0.17) (Fig. 1B). The target HSCT dose per patient was 5x106 CD34/kg. Thirty-seven patients had myeloid engraftment and 32 patients had platelet engraftment with a median of 11 and 17 days, respectively. Six patients died prior to platelet engraftment - three due to multi-organ system failure following septic shock, two due to refractory disease, and one due to adenoviremia. Early and late peripheral blood chimerism was ³ 95% at 14- and 100-days following transplantation. The probability of grade II-IV aGVHD was 28.1% (CI95: 9.3-50.7) (Fig. 2). The probability of cGVHD was 4% (CI95: 0-63.5). Conclusion: This study demonstrates safety, rapid hematopoietic engraftment, sustained donor chimerism of CD34+ enriched PBSC products with MNC cell addback with a fixed 2x105 CD3/kg dose in alloSCT recipients with a low probability of Grade II-IV aGVHD.and cGVHD. Disclosures Seiter: Novartis: Honoraria, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding, Speakers Bureau; Incyte: Honoraria, Speakers Bureau; Sanofi: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Research Funding, Speakers Bureau; Forma: Research Funding; Sun Pharma: Research Funding; Amphivena: Research Funding; Roche: Research Funding; AbbVie: Speakers Bureau; Alexion: Speakers Bureau; Onconova: Research Funding. Flower:Lentigen Technology Inc/Miltenyi Biotec: Research Funding. Cairo:Miltenyi: Research Funding; Technology Inc/Miltenyi Biotec: Research Funding; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Nektar Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Outcomes of Pediatric Patients with JMML Following Unrelated Donor Transplant: The Impact of Donor KIR Gene Content and KIR Ligand Matching

Introduction Allogeneic hematopoietic cell transplantation (HCT) remains the sole curative therapy for patients with juvenile myelomonocytic leukemia (JMML) leading to a 5-year disease-free survival of ~50%. Whether donor NK cell determinants (e.g., KIR mismatch, KIR A/B genotype) correlate with relapse and survival are unknown. We previously demonstrated that JMML stem cells, defined as Lin-CD34+CD38-, express ligands for NKG2D, NKp30, and NKp44 at levels equal or greater than AML stem cells and that colony-forming units were significantly reduced following incubation of JMML cells with NK cells. Based on these observations we hypothesized that NK cell-dependent mechanisms are a major component of protection from JMML relapse after HCT, and specifically that determinants of greater donor NK cell function (e.g. KIR Bx donors or KIR ligand mismatch) are associated with reduced relapse. We therefore investigated NK cell-related donor and recipient immunogenetics as determinants for outcomes in children transplanted for JMML. Methods: Patients (0 to &amp;lt; 19 years) who received a first allogenic HCT from an alternative donor between 2000 to 2017 and had available donor samples from the Center for International Blood and Marrow Transplant Research (CIBMTR) repository were included in the study. Donor KIR typing was performed on pre-HCT samples and results were correlated with clinical data extracted from the CIBMTR database. The primary endpoint was disease free survival (DFS); secondary endpoints included relapse rate (REL), acute graft versus host disease (aGVHD), chronic graft versus host disease (cGVHD), GVHD relapse free survival (GRFS) and overall survival (OS). Patient and transplant related variables included age (&amp;lt; 2 years vs ≥ 2 years), sex, race, performance score (&amp;lt; 90 vs &amp;gt;90), disease status, graft type (bone marrow, peripheral blood, and cord blood), HLA matching (8/8 vs others), conditioning intensity (myeloablative vs others), use of serotherapy, GVHD prophylaxis (calcineurin inhibitor (CNI)+ methotrexate (Mtx) ± others vs others) and year of HCT (2000-2007 vs 2008-2017). KIR models tested included KIR genotype (AA vs Bx), Donor KIR B content (0-1 vs ≥ 2), centromeric and telomeric region score (AA vs AB vs BB), donor KIR B content score (best, better, neutral), KIR composite score (2 vs 3 vs 4), activating KIR content, presence of activating KIR DS4, ligand-ligand (L-L) mismatch, KIR ligand (KIR-L) mismatch, and missing ligand. Proportional hazards were checked for all covariates in every model. Univariate analysis was performed for primary and secondary outcomes of interest. Covariates with overall p-value &amp;lt; 0.05 and pairwise comparisons with p-value &amp;lt; 0.05 were considered significant. L-L and KIR-L mismatch effects were studied for all outcomes in a subgroup of HLA-mismatched donors (high resolution match &amp;lt;8/8). Results: 165 patients (113 males) with a median follow up of 85 (6-216) months met the study criteria. Of these, 111 received an unrelated donor transplant and 54 received cord blood transplants. This included 77 HLA-mismatched donor transplants. Almost all (161, 98%) received myeloablative conditioning. Half of the study cohort received ATG (91, 55%) and CNI + Mtx based GVHD prophylaxis (81, 49%). Based on donor KIR genotype, 43 patients received grafts from AA donors and 122 from Bx donors. On univariate analysis, there was no difference between AA vs Bx for the primary and secondary outcomes (Table 1). Considering the various KIR models, OS was significantly better for patients without L-L mismatch in the GVHD direction (HR 0.43 (95% CI: 0.20-0.91), p=0.027). Risk of grade II-IV aGVHD was lower in patients with Bx donors (HR 0.59 (CI: 0.35-0.99), p=0.047) and donors with B content score of ≥ 2 (HR 0.51 (0.29-0.89), p=0.017) (Table 2). Conclusion: To our knowledge this is the first study analyzing NK determinants in pediatric JMML HCT recipients. OS and aGVHD were the only outcomes associated with NK cell immunogenetics, but not in expected directions. These unexpected findings may be due to our limited sample size or heterogeneity in graft sources or treatment regimens. Our study identifies a potential benefit of donor of KIR-B genotypes and absence of L-L mismatch in the GVH direction for pediatric JMML patients. These observations require further investigation for confirmation and understanding of mechanism. Disclosures Verneris: Novartis: Membership on an entity's Board of Directors or advisory committees; Fate Therapeutics: Consultancy, Current equity holder in publicly-traded company; Bmogen: Consultancy, Current equity holder in publicly-traded company; Uptodate: Consultancy. Lee:Kiadis Pharma Netherlands B.V: Consultancy, Current equity holder in publicly-traded company, Membership on an entity's Board of Directors or advisory committees, Patents &amp; Royalties.

Abo不相容性和抗a / B异凝集素滴度对血液恶性肿瘤清髓处理后输血需求和无关脐带血移植的早期结果的影响

Abstract Background:ABO incompatibility is not considered a main contraindication to allogeneic hematopoietic stem cell transplantation (aHSCT). However, it has been associated with a number of immunohematological complications. The effects of ABO incompatibility on aHSCT remain controversial.The change of isoagglutinin titers and early clinical outcomes were analyzed after unrelated cord blood transplantation (UCBT) with ABO-incompatibility donor. Methods:252 patients with hematological malignant diseases and other hematological disorders who underwent unrelated UCBT from January 2019 to April 2020 were retrospectively analyzed in this research. Patients were studied in identical, major, minor and bidirectional mismatch groups. Immunoglobulin m (IgM) isoagglutinin titers were tested one day before the transplant (-1 day), 2 weeks post-transplant, 4 weeks post-transplant and 6 weeks post-transplant. R esults:76 match,71 major mismatch, 70 minor mismatch and 35 bidirectional unrelated UCBT were identified. The median neutrophil, PLT and red blood cell (RBC) recovery days were 18, 38 and 22, respectively. ABO mismatch did not influence the neutrophil, PLT and RBC engraftment. The median of RBC transfusion in 30 days were 5 units and PLT were 6 units. There were no statisitcal difference in 0-30 days RBC and PLT transfusion after UCBT. 31-100 days transfusion was similar to in 30 days transfusion. No patients developed pure red cell anemia (PRCA). -1day IgM titers ≥1:16 did not develop higher risk of grade II-IV aGVHD when compared with titers≤1:8 group. However, we detected a marginal higher PLT transfusion in 30 days after transplant at antibody titers ≥1:16 group when compared with titers≤1:8 (P=0.051). In the major and bidirectional groups, we found that group O IgM anti-donor antibodies were displayed a significant higher than the group B anti-A titer (p&amp;lt;0.001) in setting the time one day before the transplant, but no significant with group A. 2 weeks after the transplant, group B anti-A was still showed significant lower than the group O anti-A (p&amp;lt;0.001). 4 weeks after the UCBT, we observed a modest, but no statistical significant lower titers of group B anti-A antibodies as compared with O group (P=0.097). 6 weeks after the transplant, there were no statistical significant among group O, A and B. In the multivariable Cox regression model, transfusion of ≥5 RBC units in 30 days after UCBT (HR=1.727, 95%CI=1.020-2.926, P=0.042) and PLT engraftment ≥38 days (HR=1.964, 95%CI=1.134-3.401, P=0.016) were correlated to greater risk of grade severe aGVHD. Conclusion:This study showed that ABO mismatch did not influence the neutrophil, PLT and RBC recovery time.Group O IgM anti-donor isoagglutinins in recepients showed a higher titers than the group B in setting with the time (-1 days pre-transplant, 2 weeks post-transplant, 4 weeks post-transpant). Pre-transplant higher anti-donor isoagglutinins were associated with more PLT transfusion requirements after UCBT. More RBC transfusion (≥5 units) and longer PLT recovery time (≥38 days) showed a higher incidence of severe aGVHD. Disclosures No relevant conflicts of interest to declare.

Optimization of ATG dose in haploid hematopoietic stem cell transplantation for hematologic malignancies

目的比较含不同剂量兔抗人胸腺细胞球蛋白（rATG）预处理方案单倍型造血干细胞移植（haplo-HSCT）对恶性血液病患者的疗效。方法对2013年3月至2018年12月行haplo-HSCT的恶性血液病患者进行回顾性分析，按预处理方案中rATG总量6、7.5、9 mg/kg分为ATG-6、ATG-7.5、ATG-9三组，比较三组患者急性移植物抗宿主病（GVHD）发生率、感染发生率及生存率。结果①纳入288例患者，男182例，女106例，中位年龄18（6～62）岁。急性髓系白血病（AML）128例，急性淋巴细胞白血病（ALL）110例，慢性髓性白血病（CML）8例，骨髓增生异常综合征（MDS）28例，混合细胞白血病（MAL）14例。ATG-6组159例，ATG-7.5组72例，ATG-9组57例。移植后中位随访时间为14.0（0.2～74.0）个月。②ATG-6、ATG-7.5、ATG-9组粒细胞植入率分别为96.9％、97.2％、96.5％（P＝0.972），血小板植入率分别为92.5％、87.5％、86.0％（P＝0.276），Ⅱ～Ⅳ度急性GVHD发生率分别为14.5％、11.1％、8.8％（P＝0.493），慢性GVHD发生率分别为8.8％、14.3％、12.0％（P＝0.493）。ATG-9组的CMV、EBV感染率（77.2％、12.5％）均高于ATG-6组（43.3％、3.5％）和ATG-7.5组（44.4％、1.5％）（P<0.001，P＝0.033）。③ATG-6、ATG-7.5、ATG-9组移植后3年总生存率分别为68.5％（95％CI 60.3％～77.9％）、60.1％（95％CI 48.3％～74.8％）、64.7％（95％CI 51.9％～80.7％）（P＝0.648），3年累积复发率分别为34.6％（95％CI 34.3％～35.1％）、38.0％（95％CI 37.3％～38.7％）、20.6％（95％CI 20.0％～21.3％）（P＝0.165），3年无病生存率分别为53.3％（95％CI 44.9％～63.4％）、51.9％（95％CI 41.0％～65.8％）、63.9％（95％CI 51.9％～78.7％）（P＝0.486），3年非复发死亡率分别为24.2％（95％CI 23.8％～24.5％）、26.0％（95％CI 25.4％～26.6％）、23.6％（95％CI 26.3％～28.2％）（P＝0.955）。结论低剂量rATG（6 mg/kg）可增加haplo-HSCT后Ⅱ～Ⅳ度急性GVHD的发生率，高剂量rATG（9 mg/kg）使CMV、EBV感染风险增加，中剂量ATG（7.5 mg/kg）可能是兼顾降低中重度急性GVHD和CBV/EBV感染发生率的选择。

An Alpha-Defensin Gene Single Nucleotide Polymorphism Modulates the Gut Microbiota and May Alter the Risk of Acute Graft-Versus-Host Disease

α‐defensin‐5 (HD5) accounts for 70% of the bactericidal peptide activity of Paneth cells and regulates gut microbial homeostasis. We previously reported that the G allele of rs4415345, a single nucleotide polymorphism (SNP) in the gene for HD5, was associated with approximately 40% lower risk of grade II-IV aGVHD (PMID: 30004111). Considering the role of microbiota disruptions in aGVHD, we hypothesized that rs4415345G may have a specific gut microbiota signature. First, we analyzed linked host-microbiota genetic data from 248 subjects in the Human Microbiome Project to test our hypothesis in healthy individuals. With the assumption that many microbial taxa have no association with a given SNP, we used 10-fold cross-validated Lasso regression as a test of association between rs4415345 and taxon relative abundance. A single taxon (Odoribacter splanchnicus) was retained in 99% of the simulations, always with a positive association with the G allele. Next, we evaluated whether O. splanchnicus is associated with less aGVHD in 226 patients with a 16S rRNA gene-sequenced research stool sample collected between days -30 and -6 of allo-HCT. O. splanchnicus was present in 65 (29%) patients. The univariate hazard ratio (HR) of O. splanchnicus detectability for grade II-IV aGVHD was 0.70, with a 95% confidence interval (95%CI) of 0.44-1.10 (P = 0.12). Multivariable analysis, adjusted for anti-anaerobic antibiotic exposure between days -7 and +14 yielded a similar result (HR: 0.70, 95%CI: 0.44-1.11, P = 0.13). In summary, the G allele of rs4610776 is associated with the higher relative abundance of O. splanchnicus in healthy individuals and less aGVHD in allo-HCT recipients. In an independent dataset, O. splanchnicus presence was associated with a 30% reduction in risk for aGVHD, though this association did not reach statistical significance. O. splanchnicus is a weakly butyrogenic bacterium also capable of producing indole, and depleted in patients with IBD. Both butyrate and indole can limit aGVHD. In addition, O. splanchnicus correlates with less TNFα production in response to inflammatory stimuli. We propose that O. splanchnicus may reduce aGVHD risk in rs4415345G individuals.

Relationship of Tacrolimus Concentration and Incidence of Acute Graft-Versus-Host Disease after Allogenic Stem Cell Transplantation

<h3>Introduction</h3> Acute graft versus host disease (aGVHD) remains a leading cause of morbidity and mortality in allogeneic hematopoietic stem cell transplant (allo-HSCT). Preventing GVHD without impairing the graft-versus-tumor effect remains an important goal for successful allo-HSCT. Tacrolimus (TAC), a calcineurin inhibitor that prevents T-cell activation, is commonly used as aGVHD prophylaxis. The influence of TAC has proved effective for preventing aGVHD after allo-HSCT. There is also variability in the serum concentrations of TAC and very little is known on the impact of early (first 4 weeks) TAC levels on aGVHD incidence. <h3>Methods</h3> Data were analyzed for 707 consecutive patients undergoing allo-HSCT at the Ohio State University between 2002- 2016. All patients received standard prophylaxis with TAC daily and methotrexate on days +1, +3, +6, and +11 post allo-HSCT. Tacrolimus dose was adjusted to achieve a target serum level of 5-12 ng/ml. Fine and Gray's proportional hazard models accounting for competing risks were used to evaluate the association between TAC levels and outcome of aGVHD, cGVHD, GVHD-free/relapse-free survival (GRFS),and relapse. Cox proportional hazard models were used for the association with OS. <h3>Results</h3> The mean weekly TAC concentrations at weeks 1, 2, 3 and 4 were 8.0, 9.7, 11.3 and 10.5 ng/mL, respectively. The cumulative incidence of grades II–IV aGVHD was 40% at day 100 and 45% at day 180 post HSCT. In univariable analysis, high TAC level at week 1 was associated with lower grade II-IV aGVHD (Hazard ratio (HR), 0.96; p = 0.006). We examined the effect of week 1 TAC levels categorized into tertiles (< 5.85, 5.85-8.95 and >8.95 ng/ml). Higher level of TAC (>8.95 ng/ml) was associated with lower risk of aGVHD (Figure 1a). In multivariable analysis, week 1 TAC levels > 5.85 ng/ml remained associated with a lower risk of grade II-IV aGVHD. However, only levels of 5.85-8.95 ng/ml were associated with statistically significant lower risk with HR=0.75, p=0.04 compared to the lower group (<5.85 ng/ml), adjusting for conditioning, related donors, HLA match and comorbidity index (CI). Week 1 TAC was also associated with reduced risk of cGVHD at TAC levels >7.2 ng/ml (HR: 0.78, p=0.03). The CI of cGVHD was 41% at 1 year post-allo-HSCT. Week 2 TAC level >10.6 ng/ml was associated with an increased risk of relapse (HR, 1.37, p=0.043) (Figure 1b). The cumulative incidence of relapse at 1, 3 and 5 year post allo-HSCT was 33%, 38% and 40%, respectively. TAC levels at weeks 1, 2, 3 and 4 were not associated with OS. The 1, 3 and 5 year GRFS was 21%, 14% and 12%.TAC levels at any week were not associated with GRFS. <h3>Conclusion</h3> Achieving mean whole-blood level of tacrolimus between 6.0-9.0 ng/ml within the first week post-allogenic bone marrow transplantation may reduce the risk of aGVHD.

Effect of Early Post Transplantation Tacrolimus Concentration on the Risk of Acute Graft-Versus-Host Disease in Allogenic Stem Cell Transplantation

Effect of Early Post Transplantation Tacrolimus Concentration on the Risk of Acute Graft-Versus-Host Disease in Allogenic Stem Cell Transplantation

Impact of cyclosporine A concentration on acute graft-vs-host disease incidence after haploidentical hematopoietic cell transplantation.

This retrospective study analyzed the impact of early cyclosporine A (CsA) initiation (day -3) on the risk of acute graft-vs-host disease (aGvHD) after haploidentical hematopoietic cell transplantation (Haplo-HCT) using post-transplant cyclophosphamide. Sixty-one consecutives patients who underwent Haplo-HCT were analyzed. At day +180, the cumulative incidences of grade II-IV and grade III-IV aGvHD were 39% and 18%, respectively. Patients having a lowest CsA concentration (<301ng/mL; the cutoff value used to segregate the patients between low and high CsA concentrations) in the first week after Haplo-HCT had a significantly higher risk of grade II-IV aGvHD (P=0.02), severe grade III-IV aGvHD (P=0.03), cGvHD (P=0.02), and extensive cGvHD (P=0.04). In multivariate analysis, a higher CsA concentration (≥301ng/mL) during the first week following Haplo-HCT was the only parameter significantly associated with a reduced risk of grade II-IV and grade III-IV aGvHD (RR=0.21; P=0.049 and RR<0.001; P<0.0001, respectively). We find no correlation between CsA concentration and relapse, non-relapse mortality, progression-free survival, GvHD-free and progression-free survival, or overall survival. CsA could be initiated early before Haplo-HCT with achievement of high CsA concentration to reduce the risk of aGvHD without any detrimental effect on relapse.

Achievement of High Concentration of Cyclosporine-a Is Associated with a Low Incidence of Acute Graft-Versus-Host Disease after Haploidentical Hematopoietic Cell Transplantation Using Post-Transplant Cyclophosphamide and Peripheral Blood Stem Cell Graft

Background: Allogeneic hematopoietic stem cell transplantation using a related haploidentical donor (Haplo-HCT) using post-transplant high-dose cyclophosphamide (PTCy) is increasingly used for patients lacking a matched related or unrelated donor. However, use ofperipheral blood stem cell graft (PBSC) is associated with an increased risk of acute GvHD (aGvHD) compared to bone-marrow graft. Therefore, while cyclosporine A (CsA) and mycophenolate mofetil (MMF) are traditionally initiated after completion of PT-Cy at day +5, we decided to initiate them at day -3 before transplant and to add a low dose of ATG to reinforce GvHD prophylaxis in those patients. With this background, we analyze retrospectively the impact of early initiation of CsA and of CsA concentration on patients' outcome in all patients who underwent Haplo-HCT with PBSC grafts and PTCy.Patients and Methods: Sixty-one consecutive patients who underwent Haplo-HCT for hematological malignancies between October 2013 and August 2017 were included in this retrospective single-center study. All patients received G-CSF mobilized PBSC as grafts and post-transplantation immunosuppression with CsA and MMF. CsA was administered at a dose of 3mg/kg by continuous intravenous infusion starting from D -3 and changed to twice daily oral dosing as soon as tolerated.MMF was administered at a fixed oral dose of 2g per day starting from day 6 without adjustment. In the absence of GvHD, MMF and CsA were tapered over 4 weeks starting from day 30 and day 60, respectively. CsA blood trough concentrations were monitored 3 times per week during the intravenous treatment and at least once per week after switch to oral dosing. CsA doses were adjusted to achieve blood levels between 200 and 300 ng/mL and to prevent renal dysfunction. The primary endpoint was to determine the impact of the CsA concentration on the risk of grade II-IV and III-IV aGvHD.Results: Median age was 53 (range, 15-72) years, with 16 male patients (26%) receiving a graft from a female donor. Diagnoses were myeloid (64%) or lymphoid malignancies (36%). According to the Disease Risk Index, patients were considered as low-risk, intermediate-risk, high-risk or very-high-risk (respectively 8%, 56%, 31% and 5%). Twenty-five patients (41%) with refractory disease received a sequential conditioning regimen while the remaining (n=36, 59%) received a RIC/RTC regimen based on fludarabine, busulfan and thiotepa. 51 patients (83%) received ATG (2.5-5 mg/Kg total dose) as part of the conditioning regimen. All patients received standard PTCy, nine at D+3 (15%) and 52 at D+3 and D+5 (85%). All patients engrafted at a median of 18 (range: 13-35) days after Haplo-HCT and the median follow-up among surviving patients was 21 (range: 13-53) months. The median concentrations of CsA at 1, 2, 3, and 4 weeks after Haplo-HCT were 272 (range: 114-911), 296 (range: 132-516), 251 (range: 111-485), and 246 (range: 36-375) ng/mL, respectively. At d180, the cumulative incidences (CIs) of grade II-IV and grade III-IV aGvHD were 39% and 18%, respectively. The CIs of chronic GvHD (cGvHD), extensive cGvHD and relapse were 41%, 19% and 35% at 18 months after Haplo-HCT, respectively. At 18 months after the transplant, the OS, PFS and GPFS rates were respectively 60%, 55% and 48%. In univariate analysis, patients having the lowest CsA concentration in the first week after Haplo-HCT had a significantly higher risk of grade II-IV aGvHD (49% vs 18%; P= .02), severe grade III-IV aGvHD (26% vs 0%; P = .03), cGvHD (P= .02) and extensive cGvHD (P= .04). We do not find statistically significant correlation between CsA concentration and relapse incidence, NRM, PFS, GPFS or OS. In multivariate logistic regression analysis, higher CsA concentration (> 301 ng/ mL; the cut-off value defined by ROC analysis) during the first week following Haplo-HCT was the only independent parameter significantly associated with a reduced risk of grade II-IV and grade III-IV aGvHD (respectively P = .04; RR .11; 95% CI, 0.05-0.94; and P < .0001; RR < .001; 95% CI, 0.000007-0.00006). There was no association with extensive cGvHD (P = .14; RR .11; 95% CI, 0.06-1.48).Conclusion: We conclude that achievement of high concentration of CsA early after Haplo-HCT using PBSC graft is associated with a low incidence of aGvHD and that CsA should be initiated at time of transplant with adequate monitoring during the engraftment period to reduce the risk of grade II-IV aGvHD. DisclosuresMohty:MaaT Pharma: Consultancy, Honoraria.

The Optimal Alternative Donor Transplant for Pediatric Patients with Acute Leukemia: A Comparison between Alfa-Beta T-Cell and B-Cell Depleted Haplo-SCT and UCBT

▪Children with acute leukemia (AL) in need of an allograft and lacking an HLA-identical sibling and an HLA-matched unrelated donor, could benefit either from unrelated cord blood transplantation (UCBT) or T-cell depleted haploidentical (haplo) stem cell transplantation (SCT).Different techniques of T-cell depletion have been developed for improving immune reconstitution and for enhancing the graft-versus-leukemia (GvL) effect. Locatelli et al. (Blood 2017) reported remarkable results for children with AL given haplo-SCT after a novel method of graft manipulation based on selective, negative depletion of alfa-beta T and B cells.On behalf of Eurocord, CTIWP, and PDWP of EBMT, we compared outcomes of patients < 18 years with AL undergoing either single-UCBT (n=444) or haplo-SCT after alfa-beta T-cell and B-cell-depletion (n=99) from 2012 to 2016 using a myeloablative conditioning regimen (MAC).Median age at SCT was 6 (range 0.3-18) and 8 (range 0.6-18) years, and median follow-up was 36 and 14 months (p<0.05) for UCBT and haplo-SCT recipients, respectively. Compared to UCBT, haplo-SCT were performed more recently (median year 2016 vs 2012, p<0.05). Acute lymphoblastic leukemia (ALL) was the most frequent diagnosis (62% versus 55%), while 38% and 45% of patients had acute myeloid leukemia (AML) in the UCBT and haplo-SCT group, respectively. Cytogenetics was mainly at intermediate risk for UCBT (54%) and haplo-SCT (73%, p<0.05); 49% and 54% of patients were in CR1 at time of the allograft in UCBT and haplo-SCT group, respectively (p=0.45). In vivo T-cell depletion with ATG was more frequently adopted in haplo-SCT recipients (90% versus 81%, p=0.05). For UCBT recipients, HLA compatibility was 6/6 matched for 19% of patients, 5/6 for 58% and 4/6 for 23%. Cord blood graft contained a median TNC count at cryopreservation of 7.02x10e7/Kg (range 2.63-43) and at infusion of 5.3x10e7/Kg (range 0.3-39).Conditioning regimen varied according to the type of transplant: for haplo-SCT recipients Fludarabine+TBI (28%) and Thiotepa+Busulfan+fludarabine (TBF) (24%) were the most frequent MAC. In UCBT, Busulfan+Cyclophosphamide (Cy), or Cy+Fludarabine+TBI or TBF were used in 19%, 15% and 13% of patients, respectively.Haplo-SCT recipients did not receive any additional pharmacological post-transplant graft-versus-host disease (GvHD) prophylaxis, while CyclosporineA (CSA)+ steroids and CSA+mycophenolate mofetil were used in 38% and 32% of UCBT recipients.The 60-day probability of neutrophil engraftment was 91% vs 93% (p<0.05) for UCBT and haplo-SCT. The cumulative incidence (CI) of grade II-IV and grade III-IV acute (a) GvHD was 38% vs 12% (p<0.05) and 17% vs 4% (p<0.05) in UCBT and haplo-SCT recipients, respectively. The 2-year CI of relapse (RI) was similar following from UCBT and haplo-SCT (22% vs 25%, p=0.75), as well as non-relapse mortality (NRM) (18% vs 10%, p=0.07), respectively. Disease recurrence was the most common causes of death in both groups, with infections and GvHD being the most frequent transplant-related fatalities.According to donor type, no differences were found in overall survival (OS) (65% vs 68%, p=0.17) and leukemia-free survival (LFS) (61% vs 65%, p=0.24), while a lower GvHD-free, relapse-free survival (GRFS) was observed in UCBT compared to haplo-SCT (49% vs 60%, p<0.05). OS was 67% and 58% for patients with AML and ALL respectively, p=0.11.In multivariate analysis, UCBT was associated with higher risk of NRM (HR 2.36, p<0.05), while RI was not associated with type of allograft. Higher risk of grade II-IV aGVHD was observed in UCBT (HR 2.81, p<0.05), with no difference for cGVHD among the two groups (HR 0.68, p=0.31). OS (HR 1.52, p=0.10) and LFS (HR 1.28, p=0.28) were comparable between UCBT and haplo-SCT, while GRFS resulted lower for UCBT (HR 1.58, p<0.05). No others factors were associated with outcomes.Our results showed that RI, LFS, OS and cGVHD were comparable between UCBT and haplo-SCT recipients, while better NRM, aGVHD and GRFS were observed in patients transplanted from a family donor. These data confirm that alfa-beta T-cell and B-cell depleted haplo-SCT is a valid alternative for patients in need of an urgent allograft. Costs of manipulation in the haplo-SCT setting and costs of cord blood procurement should be further investigated. Technical expertise with this refined approach of graft manipulation and center experience are important to optimize patient's outcome. DisclosuresLocatelli:Miltenyi: Honoraria; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bellicum: Consultancy, Membership on an entity's Board of Directors or advisory committees; bluebird bio: Consultancy; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Zecca:Chimerix: Honoraria. Bader:Medac: Patents & Royalties, Research Funding; Cellgene: Consultancy; Neovii: Research Funding; Riemser: Research Funding; Novartis: Consultancy, Speakers Bureau.

Influence of Age on Acute and Chronic GVHD in Children Undergoing HLA-Identical Sibling Bone Marrow Transplantation for Acute Leukemia: Implications for Prophylaxis

Relapse remains the major cause of mortality after hematopoietic cell transplantation (HCT) for pediatric acute leukemia. Previous research has suggested that reducing the intensity of calcineurin inhibitor-based graft-versus-host disease (GVHD) prophylaxis may be an effective strategy for abrogating the risk of relapse in pediatric patients undergoing matched sibling donor (MSD) HCT. We reasoned that the benefits of this strategy could be maximized by selectively applying it to those patients least likely to develop GVHD. We conducted a study of risk factors for GVHD, to risk-stratify patients based on age. Patients age <18 years with leukemia who received myeloablative, T cell-replete MSD bone marrow transplantation and calcineurin inhibitor-based GVHD prophylaxis between 2000 and 2013 and were entered into the Center for International Blood and Marrow Transplant Research registry were included. The cumulative incidence of grade II-IV acute GVHD (aGVHD) was 19%, that of grade II-IV aGVHD 7%, and that of chronic GVHD (cGVHD) was 16%. Compared with age 13 to 18 years, age 2 to 12 years was associated with a lower risk of grade II-IV aGVHD (hazard ratio [HR], .42; 95% confidence interval [CI], .26 to .70; P = .0008), grade II-IV aGVHD (HR, .24; 95% CI, .10 to .56; P = .001), and cGVHD (HR, .32; 95% CI, .19 to .54; P < .001). Compared with 2000-2004, the risk of grade II-IV aGVHD was lower in children undergoing transplantation in 2005-2008 (HR, .36; 95% CI, .20 to .65; P = .0007) and in 2009-2013 (HR, .24; 95% CI. .11 to .53; P = .0004). Similarly, the risk of grade III-IV aGVHD was lower in children undergoing transplantation in 2005-2008 (HR, .23; 95% CI, .08 to .65; P = .0056) and 2009-2013 (HR, .16; 95% CI, .04 to .67; P = .0126) compared with those doing so in 2000-2004. We conclude that aGVHD rates have decreased significantly over time, and that children age 2 to 12 years are at very low risk for aGVHD and cGVHD. These results should be validated in an independent analysis, because these patients with high-risk malignancies may be good candidates for trials of reduced GVHD prophylaxis.

Association between single nucleotide polymorphisms of tumor necrosis factor gene and grade II-IV acute GvHD: a systematic review and meta-analysis.

Acute GvHD (aGvHD) complicates up to 50% of allogeneic hematopoietic cell transplants and pre-transplant estimation of its risk can guide prophylaxis, monitoring and early intervention strategies. Inspired by the role of tumor necrosis factor alpha (TNFα) in the pathogenesis of aGvHD and the inconsistency of the association studies exploring single nucleotide polymorphisms (SNPs) of the TNF gene, we conducted a systematic review and meta-analysis of the available reports using PubMed and EMBASE. Original human studies reporting on the association between recipient TNF SNPs and grade II-IV aGvHD in a format convertible to effect size and confidence interval were included. One of the two most widely investigated SNPs (rs361525G>A) was marginally associated with increased risk of grade II-IV aGvHD in random-effects meta-analysis of six studies (627 patients in total, risk ratio=1.29, 95% confidence interval=0.99-1.69, P=0.06). If this result is validated in a large cohort with uniform conditioning and GvHD prophylaxis, TNF rs361525G>A may become a useful tool for aGvHD risk estimation before the transplant.

Refined Graft-Versus-Host Disease-Free, Relapse-Free Survival after Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Intermediate and Unfavorable Prognosis Acute Myeloid Leukemia Ttransplanted in First Complete Remission from HLA-Identical Related or Unrelated Donors: A Retrospective Study on Behalf of the ALWP of the EBMT

The refined endpoint of graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) represents an important measure of outcomes of allogeneic hematopoietic stem cell transplant (HSCT) including both clinical results and quality of life without ongoing morbidity.We analyzed the refined GRFS in 5059 patients with de novo acute myeloid leukemia (AML) with intermediate and unfavorable cytogenetics in first complete remission (CR1), undergoing HSCT from a matched sibling (MSD, n=3731) or unrelated donor (UD, n=1328). HSCT were performed between 2000 and 2015 and reported to EBMT. Median age for the whole population was 49 years (range 18-76)There were statistical differences between the 2 groups: compared to MSD, UD recipients were younger (60 vs 32 years, p<0.01), had more often a male donor (54% vs 69%, p<0.01), had a longer interval from diagnosis to HSCT (140 vs 168 days, p<0.01) and were more often transplanted from a CMV negative donor (62% vs 41%, p<0.001). UD recipients received more often reduced intensity conditioning regimen (59% vs 47%, p<0.01), in vivo T-cell depletion (TCD) (72% vs 26%, p<0.01) and peripheral blood stem cells (PBSC) (79% vs 74%, p<0.01).Median follow up was longer for MSD recipients (60 vs 32 months, p<0.01)In univariate analysis, cumulative incidence (CI) of relapse (RI) was 25% in both groups (p=0.89); UD recipients experienced a higher CI of grade II-IV acute GVHD (aGVHD, 26% vs 23%, p<0.01), of extensive chronic GVHD (cGVHD, 23% vs 19%, p<0.01), non-relapse mortality (NRM, 12% vs 15%, p<0.01) and had a lower probability of leukemia-free survival (LFS, 60% vs 63%, p<0.01) and of overall survival (OS, 65% vs 69%, p<0.01).Probability of GRFS at 4 years was not different, being 44% in both groups (p=0.9).Regardless the donor type, probability of 4-year GRFS was higher in patients receiving in-vivo TCD (48% vs 41%, p<0.01), with the use of myeloablative conditioning (45% vs 40%, p<0.01), in patients aged less than median age (47% vs 40%, p<0.01), in patients with intermediate risk cytogenetics (47% vs 33%, p<0.01), when interval from diagnosis to HSCT was higher than 5 months (45% vs 41%, p<0.03), when bone marrow was used as stem cell source (49% vs 41%, p<0.01), in female recipients (46% vs 41%, p<0.01).In a multivariate analysis adjusted for the differences between the 2 groups, UD was associated with lower GRFS (HR 1.19, CI 1.07-1.31, p<0.01), higher risk of grade II-IV aGVHD (HR 1.79, CI 1.53-2.09, p<0.01) and extensive cGVHD (HR 1.42, CI 1.19-1.69, p<0.01), higher NRM (HR 1.64, CI 1.34-1.99, p<0.01) and OS (HR 1.13, CI 1.00-1.28, p<0.01).The other factors independently associated with GRFS were unfavorable cytogenetics (HR 1.42, p<0.01), time from diagnosis to HSCT (HR 0.96, p<0.01), male recipients from female donors (HR 1.23, p<0.01), PBSC as stem cell source (HR 1.22, p<0.01), use of in-vivo TCD (HR 0.73, p<0.01).Unfavorable cytogenetics was associated with lower LFS (HR 1.64, CI 1.50-1.81, p<0.01) and OS (HR 1.68, CI 1.53-1.86, p<0.01) and higher RI (HR 1.94, CI 1.73-2.17, p<0.01).When performing a subgroup analysis according to the use (n=1955) or not (n=3104) of in-vivo TCD, GRFS was not different in the two groups (47% vs 48%, p=0.54). GRFS was lower in UD recipients not receiving in-vivo TCD (37% vs 41%, p<0.02).In multivariate analysis, a lower GRFS was observed in UD versus MSD when in-vivo TCD was not used (HR 1.23, CI 1.05-1.43, p<0.01), while no significant differences were found for those receiving in-vivo TCD. Unfavorable cytogenetics was associated to a worse GRFS in both groups.In conclusion, UD transplant is associated with lower GRFS, probably due to higher incidence of GVHD and NRM. Importantly, in-vivo TCD might improve outcomes of UD recipients, leading to a GRFS comparable to MSD recipients. Moreover, in AML in CR1, unfavorable cytogenetics remains a strong predictor of worse outcomes either in MSD and UD recipients as compared to intermediate cytogenetics. DisclosuresMaertens:Merck Sharp & Dohme: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pfizer: Consultancy, Honoraria, Research Funding, Speakers Bureau; Astellas: Consultancy, Speakers Bureau; Amgen: Consultancy; Gilead: Consultancy, Honoraria, Speakers Bureau.