post-HSCT Day Research Articles

Cerebrovascular complications of hematopoetic stem cell transplantation in patients with hematologic malignancies

Introduction. Modern transplantation and biological therapy methods are associated with a wide range of adverse events and complications. Incidence and variety of neurological complications mostly depend on myelo- and immunosuppression severity and duration as well as on donor's and recipient's characteristics. The most frequent complications involving the nervous system include neurotoxic reactions, infections, autoimmune and lymphoproliferative diseases, and dysmetabolic conditions as well as cerebrovascular complications that potentially affect transplantation outcomes.
 Objective. To evaluate the impact of post-transplantation cerebrovascular events (CVEs) on transplantation outcomes in patients with hematologic malignancies.
 Materials and methods. We analyzed 899 transplantations performed at the Raisa Gorbacheva Memorial Research Institute for Pediatric Oncology, Hematology, and Transplantation, Pavlov First Saint Petersburg State Medical University, from 2016 to 2018. We assessed transplantation parameters and donor's and recipient's characteristics by intergroup comparison, pseudo-randomization (propensity score matching), KaplanMeier survival analysis, and log-rank tests.
 Results. Post-transplantatively, CVEs developed in 2.6% (n = 23) of cases: 13 (1.4%) ischemic strokes and 11 (1.2%) hemorrhagic strokes or intracranial hemorrhages were diagnosed. CVEs developed on days 99.5 39.2 post hematopoetic stem cell transplantation (HSCT). There were more patients with non-malignant conditions in the CVE group as compared to the non-CVE group (21.7% vs 7.9%; p = 0.017). Patients with CVE had a significantly lower Karnofsky index (75.6 21.3 vs 85.2 14.9; p = 0.008). Statistically, we also note some non-significant trends: patients with CVE more often underwent allogenic HSCT (82.6% vs 64.0%; p = 0.077) while donors were more often partially (rather than totally) HLA compatible for recipients (39.1% vs 21.1%; p = 0.33). Patients with CVE more often had a history of venous thromboses (13.3% vs 4.2%; p = 0.077). Post-HSCT stroke decreased post-transplantation longevity by approximately 3 times (331.8 81.6 vs 897.9 25.4 post HSCT; p = 0.0001). In the CVE group, survival during first 180 days post HSCT (landmarks post-HSCT Day+60 and Day+180) was significantly lower as compared to that in the CVE-free group. If CVE developed during first 30 days and 100 days post HSCT, vascular catastrophe did not affect post-HSCT survival significantly.
 Conclusion. Whereas ischemic stroke is a long-term HSCT complication (beyond D+100 post transplantation), hemorrhagic stroke is a short-term complication (D0D+100 post HSCT). CVEs affect survival in patients with hematologic malignancies, especially those developed between D+60 and D+180 post HSCT. History of venous abnormalities, low Karnofsky index at HSCT initiation, and the type of allogenic HSCT, especially from half-matched donors, can be considered as negative outcome risk factors in post-HSCT CVE.

Autologous hematopoietic stem cell transplantation to treat systemic lupus erythematosus: The first case in Vietnam

Background: Systemic lupus erythematosus (SLE) is a chronic disease that causes systemic inflammation which affects multiple organs. There is no cure for SLE. Conventional treatment options include antimalarial drugs, corticosteroids, and immune suppressants, but a number of patients are resistant to treatment or suffer from severe side effects. Stem cell transplantation has been used to treat SLE for the past 2 decades. We describe the first Vietnamese patient with refractory SLE who received an autologous hematopoietic stem cell transplant. Case presentation: The patient is a woman who was diagnosed 12 years ago with systemic lupus erythematosus. She was administered corticosteroids and high-dose immunosuppressive medicines, but the condition was refractory, manifesting as severe headache, arthralgia, chronic anemia, severe Cushing's syndrome, and proteinuria. At admission, the SLEDAI score was 28 and proteinuria was 6.7g/l. She received cyclophosphamide and G-CSF for HSCT mobilization. Peripheral blood stem cells were collected and selected for CD34+ cells. Antithymocyte, cyclophosphamide, and rituximab were used in conditioning regimens. The patient was then administered a CD34+ autologous hematopoietic stem cell transfusion with a CD34+ dose of 7.93 x 106 cells/kg body weight, T and B lymphocyte purity of the graft exceeded 99.99%. Post-transplant course was favorable, the patient did not experience serious complications. Recovery of neutrophils on post-HSCT day +9 and platelet on day +12. Six months after stem cell transplantation, the patient's clinical symptoms significantly improved, the SLEDAI score dropped from 28 to 0, and the patient discontinued receiving immunosuppressive drugs. Conclusion: Autologous hematopoietic stem cell transplantation promises to be a new, effective therapeutic method that can be implemented more broadly in Vietnam for SLE patients.

Thymic activity in immune recovery after allogeneic hematopoietic stem cell transplantation in children.

Thymic output was studied prospectively in 52 children who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). Thymic activity was assessed by quantification of recent thymic emigrants (RTE) discriminated from the rest of naive T cells by immunophenotype CD3+/CD4+/CD31+/CD45RA+. Thymic output was analyzed in correlation with the kinetics of immune recovery and in relation to other potential risk factors that may influence thymopoiesis: underlying disease, type of HSCT, source of stem cells, age of recipient and donor, type of conditioning, implemented graft versus host disease (GvHD) prophylaxis, viral reactivations (herpes viruses cytomegalovirus – CMV, Epstein-Barr virus – EBV, adenovirus – ADV, BK virus – BKV), occurrence and grade of both acute and chronic graft versus host disease (aGvHD, cGvHD) and number of transplanted CD34 cells/kg. The absolute count of RTE in peripheral blood was evaluated at 6 time points: before the conditioning and on days +15, +30, +60 , +90 and +180 after HSCT. Occurrence of grade II-IV aGvHD was the most important factor associated with low RTE counts after HSCT. History of malignant disease, and transplantation from matched unrelated donor were risk factors for lower thymic output. We found a weak inverse correlation between the age of the recipient and thymic output on post-HSCT day +180. Source of stem cells, type of conditioning, viral reactivations, occurrence of chronic GvHD, age of the donor and the number of transplanted CD34 cells/kg did not affect thymopoiesis in our study group. These preliminary findings and identification of risk factors for deterioration of thymic activity may in the future help in selecting candidates for thymus rejuvenation strategies.

Tracking of AML-Associated Mutations Via Droplet Digital PCR Is Predictive of Outcomes Post-Transplant

Introduction: Allogeneic hematopoietic stem cell transplantation (HSCT) remains one of the only curative therapies for acute myeloid leukemia (AML) in adult patients. However, a high proportion of patients will relapse post-HSCT. Measurable residual disease (MRD) has emerged as highly predictive of relapse after chemotherapy and multiple studies have demonstrated inferior outcomes after HSCT for patients with pre-HSCT MRD. Fewer studies have evaluated post-HSCT MRD, but those have suggested that MRD is a powerful predictive tool in this setting as well. We have previously utilized droplet digital PCR (ddPCR) as an MRD platform to track 33 unique AML-associated mutations in a cohort of patients receiving either cytotoxic chemotherapy or targeted agents, and our preliminary data suggest that persistence or recurrence of these mutations during therapy is predictive of relapse and diminished overall survival. In the present study we sought to evaluate the utility of ddPCR specifically for post-HSCT MRD monitoring.Methods: Patients 18 years of age or older with AML who had received allogeneic HSCT were identified via retrospective chart review. Thirty-seven patients were identified who had sufficient diagnostic testing to identify AML-associated point mutations and had available DNA from serial bone marrow samples. Thirty-six of these patients had at least one pre-HSCT sample analyzed; post-HSCT day 28, day 80, and day 365 samples were available for 26, 25, and 11 patients, respectively. DdPCR was utilized to track 21 different AML-associated mutations in this patient cohort. MRD negativity was defined as variant allelic frequency (VAF) below the limit of detection for all assayed mutations (1-4 mutations per patient). Relapse-free (RFS) and overall (OS) survival were defined as time from date of transplant to relapse or death. Survival statistics were analyzed as Kaplan-Meyer curves, with p-values determined by the log-rank (Mantel-Cox) test. P-values less than 0.05 were considered statistically significant. Outcome data for all patients were censored July 6, 2018.Results: Median follow-up from time of HSCT was 13.3 months. Of the 37 patients included in this cohort, the majority (73%) received regimens containing cytotoxic chemotherapy prior to HSCT; the remainder (27%) received targeted therapies +/- low-intensity chemotherapy prior to HSCT. Only 6 of 36 patients (17%) were MRD negative pre-HSCT, all of whom had received cytotoxic chemotherapy. All 37 patients had one or more post-HSCT samples available for MRD assessment. Of these, 30 achieved MRD negativity after HSCT (81%). Post-HSCT MRD status was predictive of both RFS and OS (Figure 1). This replicates previously published data with respect to ddPCR-based MRD, but is based on evaluation of both more patients and more mutations. In agreement with previously published data showing high predictive value of the 1-month post-HSCT MRD, we found this timepoint specifically to be predictive of RFS and OS in the 26 patients for whom a sample was assayable (Figure 2). Neither outcomes nor MRD status by ddPCR varied based on conditioning regimen (myeloablative versus reduced-intensity) in our cohort (data not shown).We also compared ddPCR MRD status with whole bone marrow chimerism measured by short tandem repeat (STR) analysis. Concordance between MRD negativity and >95% donor chimerism was 69% at 1 month post-HSCT and 93% at 80 days post-HSCT. Of 8 discordant samples at the 1 month post-HSCT time point, 3 had donor chimerism <95% but were MRD negative, with no relapses to date. The other five patients had full donor chimerism with positive MRD, and 3 of 5 patients have relapsed. Of two discordant samples at 80 days post-HSCT, both involved full donor chimerism with persistence of MRD, and one patient has subsequently relapsed.Conclusions: ddPCR-based molecular MRD assessment is predictive of relapse-free and overall survival post-HSCT in patients with AML, and may be a powerful adjunct to surveillance measures already in clinical use, such as chimerism. Presence of molecular MRD specifically at 1 month post-transplant showed significant correlation with relapse and with overall mortality. Detection of AML-associated mutations at this and later time points in a prospective manner could in many cases allow salvage of patients prior to clinical relapse, thus improving survival for this high-risk population. [Display omitted] DisclosuresPollyea:Gilead: Consultancy; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Curis: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; AbbVie: Consultancy, Research Funding; Celyad: Consultancy, Membership on an entity's Board of Directors or advisory committees; Argenx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Prophylactic recombinant thrombomodulin treatment prevents hepatic sinusoidal obstruction syndrome in high-risk pediatric patients that undergo hematopoietic stem cell transplants.

Hepatic SOS is a potentially life-threatening complication of conditioning for allogeneic HSCT. rTM is a new drug for treating DIC. We report our experience of the use of rTM as a prophylaxis against SOS in high-risk pediatric patients that underwent HSCT. We evaluated the cases of 19 pediatric hematology and oncology patients who underwent HSCT at our institution between 2007 and 2016. The patients who received HSCT after 2012 (n=8) were treated with rTM as a prophylaxis against SOS together with UDCA and LMWH, whereas the others (n=11) were only treated with UDCA and LMWH. Although SOS occurred by post-HSCT day 35 in 3 (27%) patients in the control group, SOS was not seen in the rTM group. Two of the former three patients suffered severe SOS, and one died of the condition. The mean peak level of PAI-1 (a marker of endothelial damage) was significantly lower in the rTM group. rTM appears to be a safe prophylaxis for SOS. The present findings suggest that prophylactic rTM after HSCT might help to prevent SOS.

Hypoglycemia During the Temporary Interruption of Parenteral Nutrition Infusion in Pediatric Hematopoietic Stem Cell Transplantation.

Parenteral nutrition (PN) is required with pediatric procedures such as hematopoietic stem cell transplantation (HSCT). However, risks associated with temporary PN infusion interruption remain unclear. We retrospectively analyzed in 22 children undergoing HSCT receiving PN with the same daily routine: temporary PN infusion interruption before breakfast for administering a saline-diluted acyclovir drip. After correcting patients' glucose levels, we examined minimum blood glucose levels between preparative regimen initiation and post-HSCT day 30. Patients were divided into 2 groups according to a minimum glucose cutoff of 60 mg/dL. Patient background characteristics and hypoglycemia risk factors were compared between both groups. The hypoglycemia group had a significantly lower body surface area, higher glucose infusion rate (GIR), lower cholinesterase levels, and higher zinc levels at the onset of the minimum blood glucose level ( P < .05). Multivariate analyses revealed an association only between higher GIR (≥5 mg/kg/min) and hypoglycemia during the temporary PN infusion interruption. A time course analysis of blood glucose and immunoreactive insulin (IRI) levels in 1 patient revealed a combined high-caloric and saline flush before acyclovir initiation, causing temporary increased IRI, as the etiology for hypoglycemia. Particular attention and several precautions are required to prevent complications associated with temporary PN infusion interruption in children with higher GIR.

Hepatic veno-occlusive disease may develop in secondary iron overloaded mice after allogeneic hematopoietic stem cell transplantation with total body irradiation.

BackgroundThe outcome of hematopoietic stem cell transplantation (HSCT) is poor in patients with secondary iron overload (SIO). We evaluated the relationship between SIO and veno-occlusive disease (VOD) in an animal model with radiation for HSCT.MethodsWe used a 6-week-old female BDF1 (H-2b/d) and a male C57/BL6 (H-2b) as recipient and donor, respectively. Recipient mice were injected intraperitoneally with 10 mg of iron dextran (cumulative doses of 50 mg, 100 mg, and 200 mg). All mice received total body irradiation for HSCT. We obtained peripheral blood for alanine transaminase (ALT) and liver for pathologic findings, lipid hyperoxide (LH) as reactive oxygen species (ROS), and liver iron content (LIC) on post-HSCT day 1 and day 7. The VOD score was assessed by pathologic findings.ResultsALT levels increased depending on cumulative iron dose, with significant differences between days 1 and 7 for mice loaded with 200 mg of iron (P<0.01). LH levels significantly increased in mice loaded with 200 mg of iron compared to those in other groups (P<0.01). For mice loaded with 100 mg of iron, the LH level depended on the radiation dose (P<0.01). There was a statistically significant relationship among ALT, LH, and LIC parameters (P<0.05). Pathologic scores for VOD correlated with LIC (P<0.01).ConclusionLivers with SIO showed high ROS levels depending on cumulative iron dose, and correlations with elevated liver enzyme and LIC. The pathologic score for VOD was associated with the LIC. Our results suggest that SIO may induce VOD after HSCT with irradiation.

Autologous Stem Cell Transplant for Myasthenia Gravis: A Single-Centre Experience

Myasthenia Gravis is an antibody-mediated disease that affects the neuromuscular junction. Despite advances in immune-targeted therapies, a subset of patients demonstrate refractory disease with severe or life-threatening symptoms. Disease control has been achieved using autologous hematopoietic stem cell transplant (HSCT) in a variety of autoimmune conditions including multiple sclerosis, chronic inflammatory demyelinating polyneuropathy, stiff person syndrome, and others. Here we report our center’s experience using autologous HSCT in seven patients with myasthenia.Seven myasthenia patients underwent HSCT between 2001 and 2011. Six patients were female. Median age (range) was 37 at diagnosis (17-52) and 43 at HSCT (24-55). Before HSCT, myasthenia severity, standardized by the Myasthenia Foundation of America (MGFA) clinical classification, was graded as moderate in 2 patients, severe in 3 patients, and life-threatening in 2 patients. Treatment regimens included pyridostigmine in all patients, and immune-targeted therapies including: steroid therapy in all patients, an additional immunomodulating drug in 6 patients, and plasma exchange or intravenous immunoglobulin in all patients. All patients had at least one myasthenia-related emergency department visit or hospitalization prior to HSCT, 3 requiring ICU stays and 2 requiring intubation.All patients underwent HSCT mobilization with cyclophosphamide and filgrastim. Stem cells were harvested from peripheral blood and selected for CD34+ cells in all cases. Conditioning regimens used busulfan, cyclophosphamide, and antithymocyte globulin (Bu-Cy-ATG) in 4 patients, Cy-ATG and total body irradiation in 2 patients, and etoposide, melphalan and dexamethasone in 1 patient who was undergoing HSCT for relapsed follicular lymphoma (FL).Median post-HSCT follow-up was 40 months (range 29-149). At last follow-up MGFA postintervention status was classified as complete stable remission (CSR) in all patients, indicating patients bad been experiencing no myasthenia symptoms and were on no myasthenia therapy for at least one year. Six patients had no further hospitalizations or emergency department visits post HSCT. One patient required hospitalizations in the 6 months post HSCT but at time of writing had been not hospitalized for myasthenia for more than 10 years. One patient died 29 months post HSCT from relapsed FL. At time of death this patient’s myasthenia was in CSR.There were no HSCT regimen-related deaths. No patients required ICU care during HSCT admission. Absolute neutrophil count exceeded 0.5 x 109/L on median post HSCT day 11 (range 13 - 28). Median hospital stay, including administration of conditioning regimen was 34 days (range 20-43). In the first post-HSCT year the cohort experienced 6 viral reactivations in 3 patients: 3 cases CMV viremia, 1 case BK virus-induced hemorrhagic cystitis, 1 case VZV dermatitis, 1 case oral HSV. Two late post-HSCT complications were observed: one case of acquired amegakaryocytic thrombocytopenia (post-HSCT day 701), and one case of relapsed FL (post-HSCT day 846) resulting in patient death.HSCT resulted in longstanding symptom- and treatment-free remission in seven patients with refractory myasthenia gravis. The procedure was tolerable however the intense immune depletion transiently increased risk of viral reactivation. This experience demonstrates that in selected myasthenia gravis cases, HSCT is a viable option for long-term disease control. The novel application of HSCT for this and other autoimmune conditions is an area that warrants further exploration and long-term follow-up. DisclosuresNo relevant conflicts of interest to declare.

Human herpesvirus 6 reactivation on the 30th day after allogeneic hematopoietic stem cell transplantation can predict grade 2-4 acute graft-versus-host disease.

Viral infections and their occult reactivation occasionally cause not only organ damage, but also exacerbation of acute graft-versus-host disease (aGVHD), which may increase transplantation-related mortality synergistically. To determine correlations between viral reactivation and transplantation-related complications, we performed various viral screening tests on the 30th day after allogeneic hematopoietic stem cell transplantation (HSCT), and assessed the clinical implications. Between August 2007 and January 2013, 49 patients (37 men, 12 women) underwent HSCT in our hospital. The stem cell sources were bone marrow (n = 21), peripheral blood (n = 13), and cord blood (n = 15). The presence of cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpesvirus (HHV) 6, and HHV7 in plasma samples prospectively collected from HSCT recipients on day 30 after HSCT was assayed by quantitative polymerase chain reaction, and the correlations with transplantation-related complications were evaluated. The positivities of CMV, EBV, HHV6, and HHV7 were 44.9%, 22.4%, 53.1%, and 18.3%, respectively. We analyzed transplantation-related complications, and a significant correlation was found only between HHV6 and grade 2-4 aGVHD from day 30 to day 100 (P < 0.001). Using a receiver operating characteristic curve, the area under the curve was calculated as 0.86 (95% confidence interval [CI], 0.74-0.98) between the viral load (VL) of HHV6 and grade 2-4 aGVHD. The sensitivity and specificity were 79% and 93%, respectively, when a cutoff value of 87 copies/mL was used. In multivariate analysis using the Fine and Gray proportional hazards model, the clinically determined high-risk patients (P = 0.004; hazard ratio [HR], 3.69; 95% CI, 1.52-9.00) and the positivity of HHV6 (P < 0.001; HR, 9.957; 95% CI, 2.68-37.06) were extracted as independent risk factors for the cumulative incidence of grade 2-4 aGVHD on or after post-HSCT day 30. The only risk factor extracted for the elevation of HHV6 VL >87 copies/mL was cord blood transplantation (P = 0.0032; odds ratio, 7.10; 95% CI, 1.98-30.00). All of the risk factors previously reported to predict severe aGVHD were obtained only during, but not after, HSCT. Our study suggests that the reactivation of HHV6 (≥ 87 copies/mL) at 30 days after HSCT is a possible predictive marker for grade 2-4 aGVHD on or after post-HSCT day 30.

NK Cell KIR Ligand Mismatches Influence Engraftment Following Combined Haploidentical and Umbilical Cord Blood (UCB) Transplantation In Patients With Severe Aplastic Anemia (SAA)

BackgroundAllogeneic hematopoietic stem cell transplant (HSCT) is curative for patients (pts) with severe aplastic anemia (SAA). For SAA pts who lack HLA-identical donors, we explored a HSCT approach that co-infuses PBSCs enriched for CD34+ cells from a haplo-identical relative combined with a single umbilical cord blood unit (UCB). Although most pts undergoing this approach had early haplo-myeloid engraftment that was eventually supplanted by the UCB unit, engraftment patterns were highly variable; in some pts full cord myeloid chimerism was delayed greater than one year, while others had loss of cord engraftment with sustained full haplo-donor myeloid chimerism. Here, we investigated the impact of various patient, UCB, and haplo-donor characteristics, as well as NK cell KIR ligand mismatches between graft sources, on engraftment kinetics following haplo-cord HSCT. MethodsPts with SAA or SAA evolved to MDS unresponsive to immunosuppressive therapy with severe neutropenia (ANC<500), who lacked an HLA-matched donor and had an available haploidentical family member, and had at least one ≥ 4/6 matched UCB unit with a minimum TNC dose ≥1.5x107 cells/kg were eligible for HSCT. Pts were conditioned with cyclophosphamide (120 mg/kg), fludarabine (125 mg/m2), equine-ATG (160 mg/kg) and 200 cGy of total body irradiation. On Day 0, pts received a CD34 selected (Miltenyi CliniMacs) G-CSF mobilized haplo-donor allograft combined with a single UCB. Tacrolimus and MMF were given for GVHD prophylaxis. Results16 pts (median age: 18.9 yrs, range: 4.5-27.9) including 13 SAA and 3 with SAA evolved to MDS underwent haplo-cord transplant. Ten pts received a 4/6, and six pts received a 5/6 HLA-matched UCB unit. A median 3.6x107 TNC/kg (range: 1.96-6.93) from the UCB unit, and 3.3x106CD34+ cells/kg (range: 3.0-4.1) from the haplo-donor were transplanted. All 16 pts had sustained engraftment with 15/15 pts evaluable past day 100 having transfusion independence. At a median follow-up of 570 days (range: 55-1826), 14/16 pts survive for an overall survival rate of 81.8%. Two pts died at day 414 and 402 post-HSCT from viral related complications (CMV pneumonitis and limbic encephalopathy). Neutrophil and platelet recovery occurred at a median 10 (range: 9-22), and 21 (range: 10-213) days post-HSCT, respectively. By post-HSCT day 11, 15/16 pts had neutrophil recovery. Cord myeloid engraftment (cord ANC>500, calculated from chimerism data) occurred in 13/16 pts at a median 42 days. 3/16 did not achieve a cord ANC>500 but had sustained haplo-donor engraftment. The cumulative incidence of acute grade II-IV GvHD was 38.1%. Engraftment profiles were highly variable among pts; 12 achieved full cord chimerism in all cell lineages, 2 remained mixed haplo-cord chimeras, and 2 failed to have UCB engraftment but had sustained 100% haplo-donor myeloid chimerism. Higher degrees of HLA matching (out of 10 alleles) between recipient and UCB unit were associated with faster rates of full cord engraftment (p=0.006) and a higher probability of complete loss of haplo-donor chimerism (p=0.018). KIR ligand incompatibility in the haplo vs. cord direction (defined as the presence of a KIR ligand in the haplo-donor graft that is absent in the UCB unit at HLA epitopes Bw4, HLA-C Group 1 & 2, HLA-A3, and HLA-A11) negatively impacted cord myeloid engraftment. 5/5 (100%) pts who failed to achieve full cord myeloid chimerism by post-HSCT day 400 had haplo vs. cord KIR ligand incompatibility. Moreover, both pts who failed to have UCB engraftment and had sustained haplo-donor chimerism had haplo vs. cord KIR ligand incompatibility. In contrast, only 3/11 (27%) pts who achieved full cord myeloid chimerism post-HSCT by day 231 had haplo vs. cord KIR ligand incompatibility (p=0.026). KIR ligand incompatibility in the cord vs. haplo direction showed no significant effect on haplo-donor myeloid engraftment. ConclusionThese results show that haplo-cord HSCT is an effective treatment option for pts with SAA who lack an HLA-matched donor. Further, these results suggest that NK cell alloreactivity, occurring as a consequence of KIR ligand mismatch between the two graft sources, may have a negative impact on cord engraftment when haplo vs. cord KIR ligand incompatibility is present. In summary, this study highlights a novel factor that should be considered during graft selection for haplo-cord transplantation. Disclosures:No relevant conflicts of interest to declare.

Maintenance of complete remission after allogeneic stem cell transplantation in leukemia patients treated with Wilms tumor 1 peptide vaccine

Maintenance of complete remission after allogeneic stem cell transplantation in leukemia patients treated with Wilms tumor 1 peptide vaccine

Veno-occlusive Disease in Pediatric Patients After Hematopoietic Stem Cell Transplantation

Prediction of veno-occlusive disease (VOD), its precise diagnosis, and treatment have been the subject of various studies, but still remain unclear. Our goal was to investigate the levels of activated coagulation and fibrinolysis markers and natural anticoagulants in pediatric patients with VOD after hematopoietic stem cell transplantation (HSCT). We investigated 47 pediatric patients: 20 with neuroblastoma, 17 with leukemias, and 10 with lymphomas and measured the values of antithrombin (AT), protein C (PC), fibrinogen (FI), thrombin AT complex, prothrombin fragments 1+2 (F1+2), and D-dimer from day -7 to day +30 post-HSCT. Patients were monitored for the occurrence of VOD, and it occurred in 10 patients at a median post-HSCT day of 17.5 (range: 2 to 28 d). In the VOD group, at baseline the levels of FI were significantly lower, and on days +7 and +14 a relevant difference existed in F1+2 levels. The levels of PC were significantly lower on day +14. Logistic multivariate regression analysis between the groups showed significantly different D-dimer levels on day +14. On day +30, the levels of PC, AT, and F1+2 were different between these 2 groups of patients. The levels of D-dimer and F1+2 were increased, and PC and FI decreased before the clinical onset of VOD. The parameter differences may have a predictive value in VOD onset, which makes them candidates to be routinely monitored in patients after HSCT.

Use of the cytomegalovirus pp65 antigenemia assay for preemptive therapy in allogeneic hematopoietic stem cell transplantation: a real‐world review

Despite advances in surveillance strategies and antivirals, cytomegalovirus (CMV) infection continues to pose problems to patients receiving hematopoietic stem cell transplants (HSCTs). The bone marrow transplant (BMT) unit at the Singapore General Hospital embraced the preemptive strategy in late 2003. Although several studies have demonstrated its usefulness, we conducted this review to document CMV-related events at our institution. Forty-six patients underwent CMV surveillance using the CMV pp65 antigenemia (CMV Ag) assay from January 2004 to December 2005. Twenty-seven patients had CMV infection, and 19 remained antigenemia-negative. No differences were found between the 2 groups for the following potential risk factors for CMV infection: age, total number of co-morbidities, duration of neutropenia after conditioning, baseline creatinine, type of conditioning regimen (conventional vs. reduced intensity), type of transplant (matched sibling vs. others), recipient CMV status, donor CMV status, and use of total body irradiation. Two patients received alemtuzumab; both developed CMV Ag. Twelve episodes of CMV infection occurred after the 100th post-HSCT day. Two patients developed CMV disease. One of them could be considered a failure of the preemptive strategy, as she had CMV gastritis diagnosed on the same day that she became pp65-positive. The other developed CMV disease despite prompt institution of ganciclovir, although she had multiple post-HSCT complications requiring enhanced immunosuppression, as well as relapsed disease. One-year disease-free survival was 55.5% in those with CMV infection and 52.3% in those without infection. Survival was not affected by CMV infection.

Inhibition of Graft Versus Host Disease Using CD4+ CD25+ T Cells Induced with Interleukin-2 in Mismatched Allogeneic Murine Hematopoietic Stem Cell Transplantation

Background: In kidney transplantation, donor specific transfusion may induce tolerance as a result of some immune regulatory cells against the graft. In organ transplantation, the immune state arises from a relationship between the immunocompromised graft and the immunocompetent host. However, a reverse immunological situation exists between the graft and the host in hematopoietic stem cell transplantation (HSCT). In addition, early IL-2 injections after an allogeneic murine HSCT have been shown to prevent lethal graft versus host disease (GVHD) due to CD4+ cells. We investigated the induction of the regulatory CD4+CD25+ cells after a transfusion of irradiated recipient cells with IL-2 into a donor. Methods: The splenocytes (SP) were obtained from 6 week-old BALB/c mice (H-2) and irradiated as a single cell suspension. The donor mice (C3H/ He, H-2) received 5×10 irradiated SP, and 5,000 IU IL-2 injected intraperitoneally on the day prior to HSCT. The CD4+CD25+ cell populations in SP treated C3H/He were analyzed. In order to determine the in vivo effect of CD4+CD25+ cells, the lethally irradiated BALB/c were transplanted with 1×10 donor BM and 5×10 CD4+CD25+ cells. The other recipient mice received either 1×10 donor BM with 5×10 CD4+ CD25cells or the untreated SP. The survival and GVHD was assessed daily by a clinical scoring system. Results: In the MLR assay, BALB/c SP was used as a stimulator with C3H/He SP, as a responder, with or without treatment. The inhibition of proliferation was 30.0±13% compared to the control. In addition, the MLR with either the CD4+CD25+ or CD4+CD25cells, which were isolated by MidiMacs, from the C3H/He SP treated with the recipient SP and IL-2 was evaluated. The donor SP treated with the recipient cells and IL-2 contained more CD4+CD25+ cells (5.4±1.5%) than the untreated mice SP (1.4±0.3%)(P<0.01). There was a profound inhibition in the CD4+CD25+ cells (61.1±6.1%), but a marked proliferation in the CD4+CD25cells (129.8±65.2%). Mice in the CD4+CD25+ group showed low GVHD scores and a slow progression from the post-HSCT day 4 to day 9, but those in the control and 287 Immune Network ꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏꠏ 책임저자:정대철, 성모자애병원 소아과, ꂕ 403-720, 인천시 부평구 부평 6동 665 Tel: 032-510-5687, Fax: 032-503-9724, E-mail: dcjeong@olmh.cuk.ac.kr 이 논문은 2003년 가톨릭중앙의료원 성의장학 연구비원과제비에 의해 이루어졌음. 288 Jae Ho Hyun, et al