Prior Graft-versus-host Disease Research Articles

Lessons Learned from COVID-19 Pandemic: Outcomes after Sars-Cov-2 Infection in Hematopoietic Cell Transplant and Cell Therapy Recipients

Background: Coronavirus disease 2019 (COVID-19), a respiratory illness caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic in March 2020. Over 500 million cases of SARS-CoV-2 have been reported worldwide, with over 90 million being in the US. More than 6 million lives, with over 1 million only from the US, have been claimed by the pandemic. Hematopoietic cell transplant (HCT) or chimeric antigen receptor-T (CART) cell therapy recipients have a higher risk of mortality with COVID-19. In this updated analysis, we investigated the outcomes after SARS-CoV-2 infection in HCT/CART recipients. Methods: We conducted a single-center prospective study, including all (n=196) adult HCT/CART recipients who were diagnosed with COVID-19 at the University of Kansas Medical Center from March 2020 to March 2022. Baseline and disease-related characteristics were ascertained from medical records. Data were analyzed using SPSS version 21 (SPSS Inc, Chicago, IL). Bivariate analyses, using the chi-square and t-test, were performed. Kaplan-Meier and cox regression analyses were conducted. Results: The study included 196 HCT/CART recipients who acquired SARS-CoV-2 infection, including allogeneic HCT (n=91, 46%), autologous HCT (n=89, 46%), and CART (n=16, 8%) recipients. The median age was 59.8 (21.9-79.5) years; 76.5% were Caucasians and 58% were males. The median time since HCT/CART to SARS-CoV-2 infection was 25.4 (0.2-201.9) months, and 12% of patients acquired SARS-CoV-2 within the first 100 days post-HCT/CAR-T. Plasma cell (37%), myeloid (34%), lymphoid (28%) or solid (1%) malignancies were primary diagnoses. Myeloablative conditioning was performed in 64% of patients. Donors were autologous (53%), matched sibling (12%), matched unrelated (21%), and haploidentical (14%). Prior acute graft-versus-host disease (GVHD), prior chronic GVHD, active GVHD, and current immunosuppressive therapy (IST) were noted in 20%, 26.5%, 23.5%, and 25.5% of patients respectively. Concurrent infections were observed in 12% of patients. COVID-19 severity was mild (n=136, 70%), moderate (n=24, 12%), severe (n=20, 10%) or critical/fatal (n=16, 8%). Clinical findings included pneumonia or abnormal chest imaging (31%), hypoxia (19%), intensive care unit admission (9%), and mechanical ventilation (6%). Therapies included remdesivir (31%), convalescent plasma (11%), dexamethasone (15%), monoclonal antibodies (32%), and tocilizumab/baricitinib (5%). At least one dose of SARS-CoV-2 vaccine was reported in 70% of patients (45% pre-COVID, 25% post-COVID) while 3% of patients had received pre-exposure prophylaxis. The median duration of viral shedding (positive SARS-CoV-2 PCR) was 6.5 (0.3-23.4) weeks. After a median follow-up of 5.4 (0.3-24.8) months, the mortality rate was 12% with COVID-specific mortality of 8%. Of allogeneic HCT patients, 18% (n=16) developed subsequent GVHD after COVID-19 requiring systemic steroids and additional immunosuppression. Eighty-four (43%) patients were diagnosed with COVID after Sep 2021 and had the lowest COVID-specific mortality (2% compared to 12.5% in preceding months of the pandemic). Significant predictors of COVID-19 mortality included allogeneic HCT (HR 3.7, 95% CI 1.2-11.6, p=0.023), COVID-19 within 100 days of HCT/CART (HR 4.8, 95% CI 1.7-13.2, p=0.002), COVID-19 diagnosis earlier in the pandemic (HR 5.2, 95% CI 1.1-24.4, p=0.037), prior acute GVHD (HR 3.2, 95% CI 1.2-8.5, p=0.022), active GVHD (HR 3.5, 95% CI 1.3-9.2, p=0.013), and concurrent IST (OR 7.0, 95% CI 2.4-20.1, p<0.001) while prior SARS-CoV-2 vaccination significantly reduced the COVID-19 mortality (HR 0.19, 95% CO 0.05-0.68, p=0.010). In 15 patients with available data, vaccination induced protective anti-spike protein antibody response (>100 U/mL) in 67% of patients with a median titer of 656 (9-688,000) U/mL after completion of the primary vaccination series. Conclusion: Hematopoietic stem cell transplant and CART cell therapy recipients have a higher risk of morbidity and mortality with SARS-CoV-2 infection. Our findings highlight factors associated with COVID-19 mortality in HCT/CAR-T recipients. In HCT/CART recipients, strict vigilance, infection prevention measures, vaccination prioritization, close monitoring, and early aggressive treatment interventions are suggested for COVID-19 and future emerging infectious diseases. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

First-in-Human Clinical Trial of the IL-15 Super-Agonist Complex ALT-803 for Patients Relapsed after Allogeneic Hematopoietic Cell Transplantation

Background : The prognosis of hematologic malignancy patients who relapse after allogeneic hematopoietic cell transplantation (allo-HCT) remains poor and an unmet clinical need. IL-15 is a cytokine that stimulates both CD8 T cells and NK cells without significant effects on Tregs. ALT-803 is an IL-15/IL15Rα-Fc super-agonist complex with enhanced stability in vivo. We hypothesized that ALT-803 may augment T and NK cell number and function in the post allo-HCT relapse setting without Treg modulation, and initiated first-in-human phase I dose escalation clinical trial to test this idea. We previously reported preliminary results of the IV cohort (Miller JS et al, ASH 2016); here we report the complete study.Methods : Patients with hematologic malignancies that have relapsed >60 days after allo-HCT with no active graft versus host disease (GVHD), off immune-suppression, and with at least 10% donor chimerism were eligible. A phase 1 dose finding study design used a 3x3 dose escalation to define the maximal tolerated dose, followed by an expansion cohort. ALT-803 was administered to N=33 patients in 4 weekly doses via two routes: IV or SQ (Table 1). Median age was 58 (22-74) years, diagnoses primarily included AML (67%) and MDS (18%), and type of donor included matched-related (39%), matched-unrelated (21%), cord blood (27%), or related haploidentical (12%). 27% of patients had any grade of GVHD with <1% having a prior history of aGVHD > grade II, or moderate to severe cGVHD. In the IV cohort (N=16) 4 dose levels of ALT-803 were administered: 1 (n=6), 3 (n=3), 6 (n=4), and 10 (n=3) mcg/kg. In a second SQ cohort, 17 patients were treated at two dose levels, 6 (n=8) and 10 (n=9) mcg/kg. 4 patients in the SQ cohort were not evaluable and were replaced. Immunomonitoring was performed using flow and mass cytometry to evaluate changes in immune cells, with a focus on T and NK cells.Results: ALT-803 was well tolerated in both the IV and SQ cohorts; no DLTs were observed. The most common AEs were constitutional symptoms. Injection site rash occurred commonly in the SQ patients, which were self-limiting and showed a variable degree of CD8+, CD4+ T cells and NK cells on biopsies. No patients developed cytokine release or capillary leak syndromes, nor was there new onset severe GVHD or clinical progression of prior GVHD. 3 patients had grade 4 or 5 severe adverse events: sepsis (n=2) and an intracranial hemorrhage, which were expected in this high-risk patient HCT population with active disease. 3 clinical responses occurred with one CR and two patients with stable disease. For the CR (6 mcg/kg IV cohort), the patient's BM blast percentage decreased from 9% to 3%, his previously complex cytogenetics with -7 normalized, and his donor chimerism increased from 46% to 93%. Pharmacokinetic analyses revealed a longer half-life in SQ (10 mcg/kg: T1/2 29.3+10.3 h) vs. IV (10 mcg/kg: T-1/2 mean 4.87+3.46h) (Figure 1A). There was marked induction of Ki67+ NK cells peaking at day 5 post-injection, with significantly longer persistence of Ki67+ via the SQ route (10 mcg/kg, IV: 32%, SQ 70%, P=0.002). Increased NK cell percentages (Figure 1B) and absolute numbers were observed (Figure 1C). Ki67 was also induced within CD8+ T cells, but to a lesser degree than in the NK cells. Minimal induction of Ki67 was observed within CD4+ T cells. Mass cytometry was performed to deeply immunophenotype the NK cell compartment (Romee R et al, Sci Transl Med, 2016) of N=4 patients (10 mcg/kg SQ), comparing pre-, days 5 and 7 after the first dose of ALT-803. viSNE clustering of 37 different NK cell markers revealed marked alteration of the NK cell compartment after ALT-803. There were minimal changes in KIR and NKG2A expression on NK cells, but consistent upregulation of the receptors NKG2D, NKp30, and TIM-3 in vivo. There was more inter-patient variability with other receptors, with LAG-3 and DNAM-1 each being markedly upregulated in 1 of 4 patients evaluated.Conclusions: ALT-803 was a safe, well-tolerated immunostimulatory agent when administered in the post-HCT setting, which resulted in 1 CR and SD in several patients with AML and MDS. We identified distinct PK profiles following IV vs. SQ administration, and evidence of ALT-803 stimulation of the NK cell and CD8 T cell compartments, without major changes in CD4+ T cells. ALT-803 is a promising agent that warrants additional investigation in the allo-HCT setting, and in combination with other immunotherapy strategies. [Display omitted] DisclosuresJeng:Altor Bioscience: Employment, Equity Ownership. Rock:Altor Bioscience Corp: Employment. Wong:Altor BioScience: Employment, Equity Ownership. Miller:Oxis Biotech: Consultancy; Celegene: Consultancy; Fate Therapeutics: Consultancy, Research Funding.

Asymptomatic Brainstem Lesions and Pachymeningeal Enhancement After anti-PD-1 Therapy

Neurological immune-related adverse events (irAEs) are rare toxicities that occur following immune checkpoint inhibitor therapy. We propose that patients with thymic malignancies and graft-versus-host disease (GVHD) are predisposed to irAEs.We present two asymptomatic patients, one with thymoma and another with GVHD, who developed abnormal brain MRIs after treatment with programmed cell death protein 1 inhibitors. The first patient, with thymic cancer and thymoma, developed pontine enhancing MRI lesions following treatment with pembrolizumab. The second patient, with prior GVHD, developed pachymeningeal enhancement following treatment with nivolumab. IrAEs with abnormal MRI studies, despite asymptomatology, have significant impact on the treatment strategy for these patients.

Soluble C5b-9 As a Prognostic Biomarker for Thrombotic Microangiopathy at the Onset of Graft-Versus-Host Disease

Schmidt: Kypha Inc: Employment, Equity Ownership. Lee:Incyte: Research Funding; Syndax: Research Funding; Amgen: Research Funding; Novartis: Research Funding; Takeda: Research Funding; Kadmon: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; AstraZeneca: Research Funding.

Using immuno-PET imaging to monitor kinetics of T cell-mediated inflammation and treatment efficiency in a humanized mouse model for GvHD.

Hematopoietic stem cell transplantation is the only curative treatment for several hematological malignancies and immune deficiency syndromes. Nevertheless, the development of graft-versus-host disease (GvHD) after transplantation is a severe complication with high morbidity and mortality. The aim of this study was to image human T cells during GvHD development and their migration into GvHD-related organs. By using a radiolabeled anti-human CD3 monoclonal antibody (mAb), we were able to visualize GvHD progression in a humanized mouse model. Human peripheral blood mononuclear cells (PBMC) were transferred into immunodeficient mice (initially n = 11 mice/group) to induce GvHD. One group additionally received regulatory T cells (Treg) for prevention of GvHD. T cell migration was visualized by sequential small animal PET/MRI using 89Zr-labeled anti-human CD3 mAb. Flow cytometry and immunohistochemistry were used to measure T cell frequencies in relevant organs at different time points after engraftment. Using radiolabeled anti-CD3 mAb, we successfully visualized human T cells in inflamed organs of mice by 89Zr-anti-CD3-PET/MRI. Upon GvHD progression, we observed increased numbers of CD3+ T cells in the liver (22.9% on day 3; 94.2% on day 10) and the spleen (4.4% on day 3; 58.8% on day 10) which correlated with clinical symptoms. The liver showed distinct spot-like lesions representing a strong focal accumulation of T cells. Administration of Treg prior GvHD induction reduced T cell accumulation in the liver from 857 ± 177 CD3+ cells/mm2 to 261 ± 82 CD3+ cells/mm2 and thus prevented GvHD. 89Zr-labeled anti-human CD3 mAb can be used as a proof of concept to detect the exact spatio-temporal distribution of GvHD-mediating T cells. In the future, radiolabeled T cell-specific mAb could be employed as a predictive early biomarker during the course of GvHD maybe even before clinical signs of the disease become evident. Furthermore, monitoring T cell migration and proliferation might improve tailored GvHD therapy.

Graft-Versus-Leukemia Effect after Haplo-Identical Stem Cell Transplantation with Post-Transplant Cyclophosphamide in Patients with AML- No Association with Graft-Versus-Host Disease: A Study on Behalf of the Acute Leukemia Working Party of EBMT

Introduction. Allogeneic stem-cell transplantation (SCT) is a curative approach in acute myeloid leukemia (AML) by providing dose-intensive chemo-radiotherapy and enhancing a graft-versus-leukemia (GVL) effect. The GVL effect is provided by alloimmune T- cells and is usually closely associated with graft-versus-host disease (GVHD). Patients with GVHD have a lower incidence of relapse, but at high grades a higher incidence of non-relapse mortality (NRM). However, GVL can also occur independently of GVHD. The use of haplo-identical SCT is rapidly increasing over the last decade due to the introduction of non-T depleted methods, in particular with post-transplant cyclophosphamide (PTCy), with expected outcomes that are similar to other donor sources. The GVL effect after T- depleted haplo-identical SCT is mostly related to natural-killer cell alloreactivity and is not necessarily associated with GVHD. However, there is no definite data whether GVL after SCT in the non-T depleted setting is similarly associated with GVHD as in the matched donor setting.Methods. We assessed the impact of acute and chronic GVHD on SCT outcomes in patients with AML following non-T depleted haplo-identical SCT with PTCy, by using a series of landmark analyses.Results. The study included 605 patients with AML in CR1 (73%) or CR2 (27%) after non-T depleted haplo-identical SCT with PTCy, given during the years 2009-2016. The median age was 53 years (range, 18-76). 71% had myeloablative conditioning and 29% had reduced-intensity conditioning . The overall rate of acute GVHD grade II-IV and III-IV was 28.4% and 8.0%, respectively. The rates of chronic GVHD all grades and extensive were 32.7% and 12.3%, respectively. The rate of relapse and NRM were 21.8% and 18.2% and the rates of leukemia-free survival (LFS) and overall survival, 2 years after SCT were 59.9% and 64.1%, respectively. 509 patients were alive and leukemia-free 100 days after transplant. 366 had no prior acute GVHD at this landmark, 107 had acute GVHD grade II and 36 had grade III-IV. The overall rate of subsequent relapse was 20.3%, 18.3% and 11.9%, respectively (P=0.60). The overall rates of subsequent NRM were 10.3%, 19.0% and 35.7%, respectively (P<0.001). The rates of LFS were 69.4%, 62.6% and 52.4%, respectively (P=0.01). Multivariate analysis showed that acute GVHD grade II before day 100 was not associated with subsequent relapse (Hazard ratio (HR) 1.02, P=0.93), had borderline association with NRM (HR 1.79, P=0.09) and no association with LFS (HR 1.28, P=0.27). Acute GVHD grade III-IV before day 100 was not associated with subsequent relapse (HR 0.92, P=0.87), while it was associated with higher NRM (HR 5.23, P<0.001) and inferior LFS (HR 2.35, P=0.003). Both acute GVHD grade II and grade III-IV were associated with subsequent extensive chronic GVHD, HR 2.02 (P=0.04) and 6.93 (P<0.001), respectively. 393 patients were alive and leukemia-free 6 months after transplant. Out of them 316 had no prior chronic GVHD at this landmark, 55 had limited and 22 extensive chronic GVHD. The overall rate of subsequent relapse was 14.3%, 9.2% and 23.9%, respectively (P=0.60). The overall rates of subsequent NRM were 7.3%, 10.4% and 31.7%, respectively (P=0.003). The rates of LFS were 78.4%, 80.4% and 44.4%, respectively (P=0.01). Multivariate analysis showed that limited grade chronic GVHD occurring before 6 months was not associated with subsequent relapse (HR 0.69, P=0.44), NRM (HR 1.43, P=0.55) or LFS (HR 0.88, P=0.74). Extensive chronic GVHD was not associated with subsequent relapse (HR 1.44, P=0.56) but was associated with higher NRM (HR 5.77, P=0.004) and inferior LFS (HR 2.75, P=0.01). Similar results were seen for prior chronic GVHD at the 1 year landmark.Conclusions. By a series of landmark analyses at 100 days, 6 months and 1 year after SCT, we did not find any association of acute GVHD grade II or III-IV or chronic GVHD (limited or extensive) with subsequent relapse. Acute GVHD grade III-IV was associated with a higher NRM and lower LFS rates after day100. All grades of acute GVHD were associated with a higher incidence of chronic GVHD. Previous extensive chronic GVHD was also associated with a higher NRM and a lower LFS. GVL is thus not associated with GVHD after non T-deleted haplo-identical SCT with PTCy. Future novel strategies for prevention of significant GVHD are warranted. DisclosuresAngelucci:Vertex Pharmaceuticals Incorporated (MA) and CRISPR CAS9 Therapeutics AG (CH): Other: Chair DMC; Roche Italy: Other: Local (national) advisory board; Novartis: Honoraria, Other: Chair Steering Comiittee TELESTO Protocol; Celgene: Honoraria, Other: Chair DMC; Jazz Pharmaceuticals Italy: Other: Local ( national) advisory board. Mohty:MaaT Pharma: Consultancy, Honoraria.

Outcomes of Rituximab for EBV Viremia/Post-Transplant Lymphoproliferative Disease in CD34+ Selected Allogeneic Hematopoietic Stem Cell Transplantation

Recipients of T-cell depleted allogeneic hematopoietic stem cell transplants (SCT) are at high risk forEpstein Barr Virus (EBV) reactivation and post-transplant lymphoproliferative disease (PTLD). Early treatment strategies, including chemotherapy and de-escalation of immunosuppression, proved unsuccessful. Unselected donor leukocyte infusions (DLIs) can be effective, but increase the risk of graft-versus-host disease (GVHD). Rituximab is increasingly used as preemptive therapy for EBV viremia to prevent PTLD development, leading to improved outcomes.However, there are limited data on rituximab-related toxicities in this population. The purpose of this study is to retrospectively describe these outcomes and toxicities in CD34+ selected SCT.Patients who received a CD34+ selected SCT between January 2008 and February 2015 at Memorial Sloan Kettering Cancer Center were evaluated for inclusion. All patients with EBV reactivation post-transplant were included. Proven PTLD was defined as biopsy-confirmed, with corresponding clinical manifestations. Probable PTLD was defined as significant lymphadenopathy or end-organ disease with EBV viremia in the absence of another cause. All patients with EBV reactivation received rituximab per institutional guidelines.Response to rituximab was assessed by viral clearance and the criteria for PTLD, described by Cheson, et al. Patients without repeat imaging were assessed for clinical response (resolution of PTLD signs and symptoms without need for additional therapy). Toxicities assessed 1 year post-rituximab include new-onset hypogammaglobulinemia (IgG <500 mg/dL), new-onset neutropenia, (absolute neutrophil count ≤1000/mm3), and infections (e.g. viral, bacterial, and fungal).The cumulative incidence of each outcome was determined using the cumulative incidence method for competing risks, with death as the competing event. A landmark analysis investigated possible differences in outcomes related to the number of rituximab doses received by 4 weeks (>3 or ≤3 doses). Differences in outcomes due to EBV diagnosis, prior GVHD or immunosuppressant use, or number of rituximab doses by 4 weeks were evaluated using Gray’s test. For all analyses, pvalues <0.05 were considered statistically significant.Eighty-eight patients had EBV reactivation (16.6% of CD34+ selected SCT recipients). EBV viremia was most common (n=42), followed by probable PTLD (n=28), and proven PTLD (n=18). Baseline demographics are summarized in Table 1.Patients with EBV viremia received fewer doses of rituximab (median 2, range 1 - 5) compared to patients with probable (median 4, range 2 - 5) or proven PTLD (median 4, range 3 - 11). Viral clearance occurred in >95% of patients with EBV viremia and probable PTLD versus 77.7% of patients with proven PTLD. For EBV viremia, viral clearance occurred after a median of 1 dose of rituximab (range 1 - 4).Figure 1 depicts treatment responses to rituximab. The complete response (CR) rate was higher in patients with probable versus proven PTLD (39.3% vs. 22.2%). Patients with probable PTLD also had a higher clinical response rate (50.0% vs. 27.8%). Only patients with proven PTLD received subsequent therapy after rituximab (45.5%).The cumulative incidence of infection of any type was 71.8% (95% confidence interval [CI], 60.9 to 80.1) at 1 year post-rituximab. By univariate analysis, infectious outcomes were not impacted by number of rituximab doses by 4 weeks, EBV diagnosis, prior GVHD or immunosuppressant use. New-onset neutropenia occurred in 39/71 patients, with a cumulative incidence of 55.2% (95% CI, 42.7 to 66.0) at 1 year. New-onset hypogammaglobulinemia occurred in 18/64 patients, with a cumulative incidence of 28.4% (95% CI, 17.8 to 39.8) at 1 year. The cumulative incidence of hypogammaglobulinemia was significantly higher in the proven PTLD cohort (53.8% [95% CI, 22.3 to 77.5]) than in the probable PTLD (24.5% [95% CI, 9.6 to 42.9]) and viremia (19.4% [95% CI, 6.9 to 36.8]) cohorts (p=0.03).This study shows that rituximab is effective and clears EBV viremia in >95% of CD34+ selected SCT recipients with EBV viremia or probable PTLD. However, only 22.2% of patients with proven PTLD achieved a CR. Hypogammaglobulinemia and neutropenia are important toxicities of rituximab. Infectious complications were common, but difficult to attribute solely to rituximab. Further research and prolonged follow-up are needed. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Cytomegalovirus Infection in Pediatric Hematopoietic Stem Cell Transplantation: Risk Factors for Primary Infection and Cases of Recurrent and Late Infection at a Single Center

Cytomegalovirus (CMV) infection is a significant source of morbidity and mortality in allogeneic stem cell transplantation (SCT). We identified a cohort of 91 pediatric SCT patients at risk (defined as either donor and/or recipient seropositivity) for CMV infection at our institution. We retrospectively categorized at-risk SCT recipients as those who (1) were at risk of CMV infection in the post-SCT period, (2) had documented CMV infection before SCT, (3) experienced recurrence of post-SCT CMV viremia, or (4) experienced late post-SCT CMV viremia; categories were not mutually exclusive. We analyzed the impact of SCT-related factors on incidence of CMV infection and outcome, and we described the outcome of each of these cohorts. In univariate analysis, recipient CMV seropositivity, use of umbilical cord blood graft, and acute graft-versus-host disease (GVHD) predicted post-SCT CMV viremia, and the effects of acute GVHD (odds ratio, 4.018; 95% confidence interval, 1.032 to 15.643) and CMV seropositivity (odds ratio, 16.525; 95% confidence interval, 2.041 to 133.803) were confirmed in multivariate analysis. Patients with recurrence of post-SCT CMV viremia had a 50% all-cause mortality rate, compared with 12% in all 91 patients. Patients with pre-SCT CMV infection had a high incidence of post-SCT CMV infection but could successfully undergo SCT with antiviral prophylaxis and pre-emptive CMV treatment. All patients with late CMV infection had prior GVHD. Theses findings identify risk factors for post-SCT CMV infection and provide novel descriptions of childhood SCT recipients with pre-SCT, recurrent, and late CMV infection, which may contribute to risk stratification strategies for CMV at-risk patients in pediatric allogeneic SCT.

Robust Vaccine Responses in Adult and Pediatric Cord Blood Transplantation Recipients Treated for Hematologic Malignancies.

Because cord blood (CB) lacks memory T and B cells and recent decreases in herd immunity to vaccine-preventable diseases in many developed countries have been documented, vaccine responses in CB transplantation (CBT) survivors are of great interest. We analyzed vaccine responses in double-unit CBT recipients transplanted for hematologic malignancies. In 103 vaccine-eligible patients, graft-versus-host disease (GVHD) most commonly precluded vaccination. Sixty-five patients (63%; engrafting units median HLA-allele match 5/8; range, 2 to 7/8) received protein conjugated vaccines, and 63 patients (median age, 34 years; range, .9 to 64) were evaluated for responses. Median vaccination time was 17 months (range, 7 to 45) post-CBT. GVHD (n = 42) and prior rituximab (n = 13) delayed vaccination. Responses to Prevnar 7 and/or 13 vaccines (serotypes 14, 19F, 23F) were seen in children and adults (60% versus 49%, P = .555). Responses to tetanus, diphtheria, pertussis, Haemophilus influenzae, and polio were observed in children (86% to 100%) and adults (53% to 89%) even if patients had prior GVHD or rituximab. CD4(+)CD45RA(+) and CD19(+) cell recovery significantly influenced tetanus and polio responses. In a smaller cohort responses were seen to measles (65%), mumps (50%), and rubella (100%) vaccines. No vaccine side effects were identified, and all vaccinated patients survived (median follow-up, 57 months). Although GVHD and rituximab can delay vaccination, CBT recipients (including adults and those with prior GVHD) have similar vaccine response rates to adult donor allograft recipients supporting vaccination in CBT recipients.

Increased NKT-like Cells and Markers of T Cell Activation in Long Term Survivors of Allogeneic Hematopoietic Cell Transplantation

Background: Both impaired immune reconstitution (IR) of selected cellular subsets and abnormally high lymphocyte expression of activation markers, such as HLA-DR, CD25, and CD69, have been observed in recipients of HCT experiencing graft-versus-host disease (GVHD). Whether such alterations in cell subsets and expression of activation markers occurs normally in long term survivors of allogeneic HCT, including those without any prior GVHD, has not been well described.Patients and methods: 122 consecutive adult allogeneic HCT survivors who were at least 2 years beyond HCT and returning for long-term follow up were included if they had an immune reconstitution panel drawn between 9-14-11 (date of current panel antibody choice and gating strategy) and 9-5-13. Sixty-four were male, 52 underwent reduced intensity conditioning, 69 received grafts from matched unrelated donors (MUD), 60 received GVHD prophylaxis that included prednisone, 74 had prior acute GVHD, and 111 had chronic GVHD. Transplant factors considered in analyzing differences in IR and lymphocyte activation included age, sex, conditioning intensity, donor, GVHD prophylaxis, prior acute GVHD, and prior chronic GVHD. IR parameters analyzed included the absolute neutrophil, lymphocyte, monocyte, and eosinophil counts (ANC, ALC, AMC, AEC), platelet counts, and percentages of the following lymphocyte phenotypes: CD3+, CD3+/4+, CD3+/8+, double negative CD3, double positive CD4, naïve T, NK, NKT-like (CD3+56+), total B, naïve B, marginal zone-like B, switched memory B, CD4/8 ratio, and lymphocytes expressing activation markers, including CD3+HLA-DR+, CD4+25+, CD4+25bright+, CD8+CD69+.Results: CD4/8 ratio was <1 in 54 patients (44%) in this cohort of long-term survivors. Several determinants of IR showed variability with respect to different transplant-related factors. Total CD4% and CD4%CD25bright+% but not absolute counts were increased in those receiving myeloablative conditioning. CD4% was also increased in those receiving grafts from HLA-matched siblings compared to MUD. Prednisone-based GVHD prophylaxis was associated with a decreased percentage of naïve B cells compared to others. Absolute monocyte count was increased in those with a history of acute GVHD. CD3+HLA-DR+% was increased in those with chronic GVHD. As dichotomized variables below or above the normal range, increases in NKT-like cells were observed in 63% of patients (median 3.1%, IQR 1.3 – 6.8%, typically 1-2% in healthy controls) and increased T cell subsets expressing activation markers, (e.g. increased CD25 in 43% and CD69 in 25% of patients), could be observed in even in those who had never experienced GVHD. B cells were negatively correlated (r= -0.44, p<0.001) and CD69-expressing CD8+ T cells positively correlated (r=0.33, p=0.005) with NKT-like cells. History of acute GVHD was associated with increased CD4+25bright+ T cells during long term follow up (increased in 10% of patients with a history of acute GVHD, compared to 1.6% of those without a history of acute GVHD, p=0.046), otherwise no significant differences in those who had acute or chronic GVHD versus those who never had GVHD were identified.Conclusions: Over half of long-term allogeneic HCT survivors have an increased percentage of circulating NKT-like cells. In addition, many survivors, including those who have never had GVHD, have abnormally high expression of T cell activation markers. Despite most of this cohort exhibiting clinical tolerance with treated chronic GVHD, subclinical abnormalities in lymphocyte activation remained detectable. Further longitudinal studies are needed to determine whether these abnormalities predict future flares of chronic GVHD, susceptibility to infections, or other post-HCT complications. DisclosuresNo relevant conflicts of interest to declare.

Competing Risks and Multistate Models

Complex clinical endpoints are present in studies in cancer. Especially in studies on hematopoietic stem-cell transplantation (HSCT), various risks exist after HSCT. Patients can experience acute and chronic graft versus host disease (GVHD) or need to undergo immunosuppressive therapy (IST), a relapse can occur, or patients can die after relapse or without former relapse (nonrelapse mortality, NRM). Sometimes, endpoints can be reasonably combined in a composite endpoint, as, for example, relapse and NRM are combined into disease-free survival (DFS). In this case, standard survival techniques, as Kaplan-Meier estimation of the DFS probability, can be applied. Often, interest focuses on endpoints for which competing risks are present, as, for example, GVHD, with death without prior GVHD as competing risk. This results in a competing risks model, a special case of a multistate model. A more complex multistate model is required when the effects of events occurring in the course of the study on further disease process shall be investigated, as, for example, the effect of GVHD on relapse and NRM. Another endpoint of interest is time under IST. As patients usually experience multiple episodes of IST, thus switching back and forth between "IST" and "no IST" during follow-up, the multistate model used for analysis must be adapted for this event structure. The aim of this nontechnical report is to explain use and interpretation of Cox-type regression models suitable for the different situations in a randomized trial on the effects of anti-T-cell globulin as GVHD prophylaxis.

Outcome and Prognostic Factors for Patients Who Relapse After Allogeneic Stem Cell Transplantation.

AbstractAbstract 3069▪▪This icon denotes a clinically relevant abstractDisease relapse remains a major obstacle to the success of allogeneic hematopoietic stem cell transplantation (HSCT) for patients with hematologic malignancies (HM), and the principal cause of failure after reduced intensity conditioning HSCT. Much work has focused on identifying the risk factors for relapse and devising strategies for its prevention, but comparatively little is known about the outcome of patients who relapse and the relevant prognostic factors in this setting. We conducted a retrospective study of 1080 consecutive adult patients with HM transplanted at our institution between 2004 and 2008. 351 (33%) relapsed at a median of 4.5 months after HSCT. The 4-year post-relapse overall survival (pr-OS) was 15%, with a median post-relapse follow-up of 39 months. Significant risk factors for post-relapse mortality included shorter time to relapse, higher disease risk index1 at HSCT, myeloablative conditioning, and high HCT-CI2 at HSCT. While being on immunosuppression at the time of relapse did not significantly affect outcome in multivariable models, a history of acute or chronic graft-versus host disease (GVHD) prior to relapse conferred a higher risk for death after relapse. Based on those 5 factors and their hazard ratio for mortality in the Cox models, we constructed a simple risk score that stratified patients into 4 groups, with 4-year pr-OS ranging from 64% in patients with fewer than 3 points (13% of the cohort, among whom over one third had myeloid diseases) to 0% in those with greater than 6 points (p<0.0001) (Figure). This score performed similarly in a historical validation cohort of 276 relapsed patients who were transplanted between 1998 and 2003. An analysis of the impact of post-relapse treatment on outcome showed that immune manipulation, through either donor lymphocyte infusion or repeat HSCT, was associated with significantly better pr-OS (4-year pr-OS 28% versus 9%, p<0.0001). Even though this likely reflects in part selection bias, the difference remained significant in models that accounted for other post-relapse prognostic factors, in landmark analyses of patients who survived at least 2 months from relapse, and in patients with active GVHD at the time of relapse. The results of this study may aid with prognostication and management of patients who relapse after HSCT, as well as motivate the design of clinical trials aimed at relapse prevention or treatment in the higher-risk groups. [Display omitted] Risk factors are: •Disease Risk Index (0 points for low risk, 1 point for intermediate, 2 points for high or very high)1•Time to relapse (0 points for >24 months, 1 point for 6–24 months, 2 points for 3–6 months, 3 points for <3 months)•HCT-CI (0 points for index of 0–2, 1 point for index of 3+)2•Myeloablative conditioning (1 point)•Prior GVHD (1 point) Disclosures:No relevant conflicts of interest to declare.

Immunity after (re)vaccination of paediatric patients following haematopoietic stem cell transplantation

Loss of specific immunity follows allogeneic haematopoietic stem cell transplantation (HSCT) in the majority of cases. Responses to (re)vaccinations can be used as indicators of a functional immunological recovery. Twenty-three paediatric recipients of HSCT were enrolled in a single centre setting and responses to scheduled immunizations analysed. Immunity to vaccine-preventable diseases was impaired post HSCT, but (re)vaccinations induced protective responses in 59-100%, depending on the vaccine, regardless of prior graft-versus-host disease (GVHD) history. Despite the marked impact of moderate to severe chronic prior GVHD on both the qualitative and quantitative T-cell recovery post allogenic HSCT, most paediatric recipients of allogeneic stem cell grafts appear to attain protective antibody levels after immunization.

Association of Graft-Versus-Host Disease and Immunosuppressive Treatment with Risks of Recurrent Malignancy and Mortality After Allogeneic Hematopoietic Cell Transplantation

AbstractAbstract 218 Background:Graft-versus-leukemia (GVL) effects are closely associated with graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). In a reexamination of GVL effects, we evaluated acute and chronic GVHD defined by NIH consensus criteria and immunosuppressive treatment (IST) as risk factors for recurrent malignancy after HCT. Patients and methods:We analyzed a cohort of 2656 consecutive patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML), myelodysplastic syndrome (MDS) or myeloproliferative neoplasms (MPN) who received allogeneic HCT after high-intensity conditioning between 1992 and 2005. The onset of NIH chronic GVHD was ascertained by retrospective chart review using follow-up information obtained by our Long Term Follow Up clinic. Rates and hazards of recurrent malignancy and mortality were analyzed according to GVHD and IST as time-varying covariates. To illustrate the effect of time-varying covariates, we calculated the rate of recurrent malignancy per patient-year according to prior GVHD within sequential 90-day intervals after HCT. Cox proportional hazard models were adjusted for potential factors affecting outcomes. Results:The median patient age at HCT was 39 years (range, 0 to 71 years). Donors were HLA-identical relatives (n=1088), HLA-matched unrelated volunteers (n=912), HLA-mismatched relatives (n=243), and HLA-mismatched unrelated volunteers (n=413). GVHD prophylaxis was mostly cyclosporine and methotrexate (n=1885, 71%). Relapse rates per patient-year declined from 3 months until at least 36 months after HCT for patients with prior acute GVHD or NIH chronic GVHD (Figure). Patients without prior GVHD showed a much less pronounced decline between 12 and 30 months after HCT. Adjusted Cox analysis showed that acute GVHD and NIH chronic GVHD were associated with statistically similar reductions in risk of late recurrent malignancy beyond 18 months after HCT, with no incremental effect of chronic GVHD in patients with prior acute GVHD (Table 1). GVL effects were demonstrable in patients with CML or AML but not in those with ALL or MDS/MPN. Discontinuation of IST was associated with a decreased risk of recurrent malignancy among patients without prior GVHD but not among those with prior GVHD (Table 2). Grades III–IV acute GVHD and NIH chronic GVHD with prior acute GVHD were associated with a statistically significant increase in risk of early mortality between 3 and 18 months, but grade II acute GVHD and NIH chronic GVHD without prior acute GVHD were not. [Display omitted] Conclusion:Both acute and NIH chronic GVHD are associated with potent GVL effects, but NIH chronic GVHD does not confer any incremental benefit after acute GVHD. Withdrawal of IST was associated with a reduction in risk of recurrent malignancy in patients without prior GVHD. Analyses of GVL effects should account for time from HCT, the history of GVHD, type of malignancy and IST. Immune manipulations such as prophylactic donor lymphocyte infusion or early withdrawal of IST may represent reasonable approaches to decrease the risk of recurrent malignancy in patients without prior GVHD, if the risk of GVHD could be minimized. Disclosures:No relevant conflicts of interest to declare.

Herpes Zoster (HZ) Infection in the Post-Hematopoietic Stem Cell Transplant Pediatric Population May Be Preceded by Transaminitis.

HZ infection is a common complication following hematopoietic stem cell transplantation (HSCT). We reviewed the incidence, complications, and associated risk factors in a post-HSCT pediatric population at a single center and examined whether antecedent blood counts or transaminase levels (AST, ALT) might predict the onset of infection prior to the development of skin manifestations. Seventy-eight children between the ages of 2 months and 21 years developed HZ among the 309 patients, on whom data was available, who underwent HSCT from January 1995 to December 2002. Underlying diagnoses included: acute leukemia (n=108), chronic myelogenous leukemia (n=22), myelodysplastic syndrome (n=24) and other conditions (n=155). Two hundred patients underwent an allogeneic HSCT (98 sibling donor, 102 unrelated donor) and 109 underwent an autologous HSCT. The incidence of HZ was 25% by 10 months and 40% by 70 months post-HSCT. Post-herpetic neuralgia occurred in 21/73 (29%; 95% CI=19%, 41%) evaluable patients, disseminated skin involvement in 15/74 (20%; 95% CI= 12%, 31%) patients and visceral organ involvement in 6/75 (8%; 95% CI= 3%, 17%) patients. Acyclovir prophylaxis for cytomegalovirus (CMV) antigen positivity was given for 21 days post-BMT in 49/75 (65%) patients and had no impact on the incidence or onset of HZ, nor did immune compromise (defined as history of chemotherapy or underlying primary immune deficiency) prior to HSCT. Risk factors for development of HZ included: patient age-greater than 10 years (p<0.0001), allogeneic HSCT (p<0.001), and conditioning with total body irradiation (TBI) (p<0.059). Type of allogeneic donor did not add significantly to the model. Graft-versus-host-disease (GVHD) increased the interval to HZ infection (p<0.0018). There was insufficient evidence to attribute this surprising result to CMV prophylaxis. However, prior GVHD did increase the risk of disseminated skin involvement (p<0.016). There was a significant change in ALT level in the month preceding diagnosis of HZ (p<0.02), with 22/37 (59%) evaluable patients having a progressive increase. This rise in ALT level was not associated with GVHD (p=0.60). Changes in AST levels, white blood cell and platelet counts were not significant. Forty-four patients were admitted to hospital for HZ infection for a median of 6 days (range 2–39). Length of stay for allogeneic patients was significantly affected by skin dissemination and visceral involvement (p<0.023 and p<0.034, respectively) and not by donor type, prior immune status, GVHD or TBI. Inclusion of HZ infection post-HSCT in the differential diagnosis of patients with a rising ALT level, particularly if > 10 years of age after allogeneic HSCT with TBI conditioning may allow for earlier initiation of therapy with less morbidity and decreased need for hospital admission.

Additional Stem Cell Therapy for Graft Failure after Allogeneic Bone Marrow Transplantation

In this study we retrospectively evaluated the effect and outcome of a boost dose of donor stem cells without additional chemotherapy or total body irradiation. Between March 1983 and August 1999, 20 of 788 (2.5%) patients receiving allogeneic bone marrow transplantation (BMT) were treated with an additional boost dose of donor cells. The reasons for the use of the boost treatment were primary graft failure (early rejection; n = 7), secondary graft failure including late rejection (n = 10), refractory pure red cell aplasia caused by the remaining recipient cells producing anti-erythrocyte antibodies (n = 2), and donor lymphocyte infusion induced pancytopenia (n = 1). The patients were aged from 17 to 48 years (median age 31 years). The underlying diseases of the patients were severe aplastic anemia in 12 patients, acute myelogenous leukemia in 3, acute lymphocytic leukemia in 3, and chronic myelogenous leukemia in 2. The donors were human leukocyte antigen-identical siblings in 18 cases, 1 mismatched related donor, and 1 unrelated donor. The cell source was bone marrow in 6 cases and peripheral blood progenitor cells in 14. The median interval between BMT and the boost treatment was 7 weeks (range 1–124). No conditioning regimen was given prior to the boost treatment for 11 patients, while 4 received total nodal irradiation (TNI) plus antithymocyte globulin (ATG), 3 ATG alone, and 2 TNI plus steroid. The median infused booster mononuclear cell dose was 2.55 × 10⁸/kg (range 0.28–37.0). Fifteen (75%) patients achieved a hematological recovery. After the boost treatment, 6 of 20 (30%) patients developed acute graft-versus-host disease (GVHD) ≧ grade II, 3 of whom had had prior GVHD. Five (31.3%) of the evaluable 16 patients developed chronic GVHD. The GVHDs were easily controlled using immunosuppressive agents except in the case of 1 patient. Five patients died after the boost treatment; 2 within 30 days, 2 within 60 days, and 1 after 32 months. The causes of death were: 3 engrafment failures, 1 late rejection, and 1 infection following GVHD. With a median follow-up of 31.5 months (range 6–92), the Kaplan-Meier method estimated that the overall survival rate 1 and 3 years after the boost treatment was 80 and 71%, respectively. The survival of patients with primary graft failure was determined to be significantly lower compared to that of patients with secondary graft failure, using the log rank test (p = 0.0176). Disease category, stem cell source, conditioning prior to a boost treatment, and year of boost treatment did not have an influence on survival. We conclude that the reinfusion of donor stem cells is frequently successful in achieving engraftment with rare occurrence of fatal GVHD. Furthermore, relatively good long-term survival was demonstrated.