Characterization of clonal dynamics using duplex sequencing in donor-recipient pairs decades after hematopoietic cell transplantation.

After allogeneic hematopoietic cell transplantation (HCT), a very small number of donor stem cells reconstitute the recipient hematopoietic system, whereas the donor is left with a near-normal pool of stem cells. We hypothesized that the increased replicative stress on transplanted donor cells in the recipient could lead to the disproportionate proliferation of clonal hematopoiesis (CH) variants. We obtained blood samples from 16 related donor-recipient pairs at a median of 33.8 years (range: 6.6 to 45.7) after HCT, including the longest surviving HCT recipients in the world. For 11 of 16 pairs, a donor sample from the time of HCT was available for comparison. We performed ultrasensitive duplex sequencing of genes recurrently mutated in myeloid malignancies and CH, as well as a set of functionally neutral genomic regions representative of human genomic content at large. CH variants were observed in all donors, even those as young as 12 years old. Where donor pre-HCT sample was available, the average mutation rate in donors compared to recipients post-HCT was similar (2.0% versus 2.6% per year, respectively) within genes recurrently mutated in myeloid malignancies. Twenty-two (5.6%) of the 393 variants shared between paired donors and recipients post-HCT showed ≥10-fold higher variant allele frequency (VAF) in the recipient. A longer time since HCT was positively associated with the expansion of shared variant VAFs in the recipient. In conclusion, even decades after HCT, there does not appear to be widespread accelerated clonal expansion in the transplanted cells, highlighting the immense regenerative capacity of the human hematopoietic system.

American Society for Transplantation and Cellular Therapy International Affairs Committee: Report of the 4th Workshop on Quality as a Development Tool for Hematopoietic Cell Transplantation Programs at the 2023 Tandem BMT Meetings.

We provide a summary of the 4th ASTCT International Workshop with presentations from experts from Chile ("Setting Up a Transplantation Program in Chile," by Dr Pablo Ramirez), Saudi Arabia ("Developing Quality Programs in North Africa," by Dr Amal Alseraihy), and Japan ("The Japanese Transplant Registry Unified Management Program [TRUMP]: Current Issues and the Future," by Dr Yoshiko Atsuta). Workshop objectives included: (1) recognizing the benefits and importance for low- and middle-income countries of developing quality criteria and programs beyond existing accreditation programs, such as the Foundation for the Accreditation of Cellular Therapy (FACT) and the Joint Accreditation Committee ISCT-Europe and EBMT (JACIE); (2) describing the relationships among monitoring outcomes, including mortality, improvement of care, data reporting, and associated costs; and (3) reviewing how quality structures have been implemented and are improving care worldwide.

Patient-reported treatment response in chronic graft-versus-host disease.

Chronic graft-versus-host disease (GvHD) treatment response is assessed using National Institutes of Health (NIH) Consensus Criteria in clinical trials, and by clinician assessment in routine practice. Patient-reported treatment response is central to the experience of chronic GvHD manifestations as well as treatment benefit and toxicity, but how they correlate with clinician- or NIH-responses has not been well-studied. We aimed to characterize 6-month patientreported response, determine associated chronic GvHD baseline organ features and changes, and evaluate which patientreported quality of life and chronic GvHD symptom burden measures correlated with patient-reported response. From two nationally representative Chronic GVHD Consortium prospective observational studies, 382 subjects were included in this analysis. Patient and clinician responses were categorized as improved (completely gone, very much better, moderately better, a little better) versus not improved (about the same, a little worse, moderately worse, very much worse). At six months, 270 (71%) patients perceived chronic GvHD improvement, while 112 (29%) perceived no improvement. Patient-reported response had limited correlation with either clinician-reported (kappa 0.37) or NIH chronic GvHD response criteria (kappa 0.18). Notably, patient-reported response at six months was significantly associated with subsequent failure-free survival. In multivariate analysis, NIH responses in eye, mouth, and lung had significant association with 6-month patient-reported response, as well as a change in Short Form 36 general health and role physical domains and Lee Symptom Score skin and eye changes. Based on these findings, patient-reported responses should be considered as an important complementary endpoint in chronic GvHD clinical trials and drug development.

Association of Self-Reported COVID-19 Vaccination Status with COVID-19 Infection among Adult Long-Term Hematopoietic Cell Transplantation Survivors.

Hematopoietic cell transplantation (HCT) recipients experience significant morbidity and mortality from coronavirus disease 19 (COVID-19) infection. Data are limited regarding long-term HCT survivors' uptake of and experiences with COVID-19 vaccination and infection. This study aimed to characterize COVID-19 vaccination uptake, use of other prevention measures, and COVID-19 infection outcomes in adult HCT recipients at our institution. Between July 1, 2021, and June 30, 2022, long-term adult HCT survivors were surveyed regarding overall health, chronic graft-versus-host (cGVHD) status, and experiences with COVID-19 vaccinations, prevention measures, and infections. Patients reported COVID-19 vaccination status, vaccine-related adverse effects, use of nonpharmaceutical prevention measures, and infections. Comparisons by response and vaccination status were performed using the chi-square test and Fisher exact test for categorical variables and the Kruskal-Wallis test for continuous variables. Of 4758 adult HCT survivors who underwent HCT between 1971 and 2021 and consented to participate in annual surveys, 1719 (36%) completed the COVID-19 module, and 1598 of 1705 (94%) reported receiving ≥1 dose of COVID-19 vaccine. Severe vaccine-related adverse effects were infrequent (5%). Among respondents receiving an mRNA vaccine, completion of doses according to the Centers for Disease Control and Prevention's vaccine recommendations at the time of survey return was 2 doses in 675 of 759 (89%), 3 doses in 610 of 778 (78%), and 4 doses in 26 of 55 (47%). Two hundred fifty respondents (15%) reported COVID-19 infection; 25 (10%) required hospitalization. Vaccinated respondents reported significantly higher uptake of household vaccination (1284 of 1404 [91%] versus 18 of 88 [20%]; P < .001) and the use of nonpharmaceutical interventions (P < .001). Vaccinated respondents were significantly less likely to have contracted COVID-19 (85 of 1480 [6%] versus 130 of 190 [68%]; P < .001), as were their household members (149 of 1451 [10%] versus 85 of 185 [46%]; P < .001). Receipt of additional COVID-19 vaccine doses beyond the first dose was associated with a reduced risk of COVID-19 infection (odds ratio, .63; 95% confidence interval, .47 to .85; P = .002). Vaccination was well tolerated and associated with a lower risk of COVID-19 infection among HCT survivors and their household contacts. Vaccination and booster doses should be encouraged as part of a multifaceted approach in this high-risk population.

Prognostic Value of Cutaneous Disease Severity Estimates on Survival Outcomes in Patients With Chronic Graft-vs-Host Disease.

Importance: Prior studies have demonstrated an association between cutaneous chronic graft-vs-host disease (cGVHD) and mortality. Assessment of the prognostic value of different measures of disease severity would assist in risk stratification. Objective: To compare the prognostic value of body surface area (BSA) and National Institutes of Health (NIH) Skin Score on survival outcomes stratified by erythema and sclerosis subtypes of cGVHD. Design, Setting, and Participants: Multicenter prospective cohort study from the Chronic Graft-vs-Host Disease Consortium including 9 medical centers in the US, enrolled from 2007 through 2012 and followed until 2018. Participants were adults and children with a diagnosis of cGVHD requiring systemic immunosuppression and with skin involvement during the study period, who had longitudinal follow-up. Data analysis was performed from April 2019 to April 2022. Exposures: Patients underwent continuous BSA estimation and categorical NIH Skin Score grading of cutaneous cGVHD at enrollment and every 3 to 6 months thereafter. Main Outcomes and Measures: Nonrelapse mortality (NRM) and overall survival (OS), compared between BSA and NIH Skin Score longitudinal prognostic models, adjusted for age, race, conditioning intensity, patient sex, and donor sex. Results: Of 469 patients with cGVHD, 267 (57%) (105 female [39%]; mean [SD] age, 51 [12] years) had cutaneous cGVHD at enrollment, and 89 (19%) developed skin involvement subsequently. Erythema-type disease had earlier onset and was more responsive to treatment compared with sclerosis-type disease. Most cases (77 of 112 [69%]) of sclerotic disease occurred without prior erythema. Erythema-type cGVHD at first follow-up visit was associated with NRM (hazard ratio, 1.33 per 10% BSA increase; 95% CI, 1.19-1.48; P < .001) and OS (hazard ratio, 1.28 per 10% BSA increase; 95% CI, 1.14-1.44; P < .001), while sclerosis-type cGVHD had no significant association with mortality. The model with erythema BSA collected at baseline and first follow-up visits retained 75% of the total prognostic information (from all covariates including BSA and NIH Skin Score) for NRM and 73% for OS, with no statistical difference between prognostic models (likelihood ratio test χ2, 5.9; P = .05). Conversely, NIH Skin Score collected at the same intervals lost significant prognostic information (likelihood ratio test χ2, 14.7; P < .001). The model incorporating NIH Skin Score instead of erythema BSA accounted for only 38% of the total information for NRM and 58% for OS. Conclusions and Relevance: In this prospective cohort study, erythema-type cutaneous cGVHD was associated with increased risk of mortality. Erythema BSA collected at baseline and follow-up predicted survival more accurately than the NIH Skin Score in patients requiring immunosuppression. Accurate assessment of erythema BSA may assist in identifying patients with cutaneous cGVHD at high risk for mortality.

Frailty in Patients with Chronic Graft-versus-Host Disease.

Frailty is an increasingly recognized clinical diagnosis associated with high risk of disability and mortality. Frailty in patients after hematopoietic cell transplantation (HCT) is associated with increased nonrelapse mortality (NRM) and decreased overall survival (OS). Frailty has not been studied extensively in patients with chronic graft-versus-host disease (cGVHD). The objectives of the present study were to assess the prevalence and clinical correlates of frailty and the association of frailty with NRM and OS in patients enrolled in the Chronic GVHD Consortium. Patients were characterized as frail if they met the Fried definition of ≥3 of the following criteria at enrollment: unintentional weight loss, exhaustion, slow walking speed, low physical activity, and weakness. Frailty was assessed retrospectively using surrogate measures for the 5 domains of frailty. Frailty, cGVHD organ scores, and patient-reported outcomes were measured at the time of enrollment. The study included 399 patients from 9 centers in the United States, with 32% characterized as frail and 68% as not frail. The median duration of follow-up from enrollment was 9 years (interquartile range, 7 to 11 years). Frail patients were more likely to be older (P = .004), to have a lower Karnofsky Performance Status (P < .001), to have severe cGVHD (P < .001), and to have gastrointestinal (P < .001), liver (P = .04), or lung cGVHD (P = .002). In a multivariable analysis, older age, increased cGVHD global severity, and thrombocytopenia were statistically significantly associated with frailty when cGVHD organ involvement was excluded. A separate analysis excluding cGVHD severity and including organ involvement showed that lung and liver cGVHD and older age were associated with frailty. Neither corticosteroid use at the time of enrollment nor the maximum recorded dose of corticosteroids before enrollment was associated with frailty. Frail patients had higher NRM than nonfrail patients (P < .001), with a 10-year cumulative incidence of 41% (95% confidence interval [CI], 32% to 49%) versus 22% (95% CI, 17% to 28%). Reciprocally, frailty also was associated with a significantly lower OS (P < .001), with a 10-year OS of 43% (95% CI, 35% to 53%) in frail patients versus 63% (95% CI, 57% to 69%) in nonfrail patients. In multivariable analysis that included the individual domains of frailty, weakness, low physical activity, and slow walking speed were associated with survival. Frail patients also had worse scores on various measures of patient-reported outcomes, including the Short Form (SF)-36, the Lee Symptom Scale, and the trial outcome of the Functional Assessment of Cancer Therapy-Bone Marrow Transplantation (FACT-BMT) index score. Frail patients with cGVHD have significantly worse outcomes than nonfrail patients. Such clinical features as older age and lung and liver cGVHD are associated with frailty. Earlier clinical recognition of frailty in patients with cGVHD may prompt interventions to counteract frailty that could be beneficial for this population.

Chronic graft-versus-host-disease treatment in Brazil: analyses of failure-free survival.

Failure-free survival (FFS), defined as the absence of new systemic treatment, recurrence of original malignancy and mortality not associated with recurrence after allogeneic hematopoietic stem cell transplantation (HCT), is a robust clinical measure to interpret results of initial systemic treatment of chronic graft-versus-host disease (cGVHD). We evaluate FFS after initial treatment of cGVHD in a mixed-race cohort from a resource-constrained country. This retrospective study included 354 consecutive patients after their first HCT between January 2014 and August 2020, who received initial systemic treatment for moderate or severe cGVHD at 13 Brazilian centers. Cox regression models were used to identify risk factors for treatment failure. The overall median follow-up among survivors was 28 months (range 1-71) after initial treatment. FFS was 89% at 6 months, 71% at 1 year and 52% at 2 years. New systemic treatment was the major cause of failure. In multivariable models, prior grades II-IV acute GVHD, a National Institutes of Health severity score of 3 in liver, gastrointestinal tract or lung involvement, and onset of initial treatment of cGVHD within 12 months after transplantation were all associated with an increased risk of treatment failure. Our results could serve as a benchmark for the design of future clinical trials evaluating initial treatment of cGVHD in resource-constrained locations.

Impact of GVHD prophylaxis on CMV reactivation and disease after HLA-matched peripheral blood stem cell transplantation.

The kinetics of early and late cytomegalovirus (CMV) reactivation after hematopoietic cell transplantation using various methods of graft-versus-host-disease (GVHD) prophylaxis are poorly defined. We retrospectively compared CMV reactivation and disease among 780 seropositive patients given HLA-matched peripheral blood stem cell (PBSC) grafts and calcineurin inhibitor plus posttransplantation cyclophosphamide (PTCy; n = 44), mycophenolate mofetil (MMF; n = 414), or methotrexate (MTX; n = 322). Transplantation occurred between 2007 and 2018; CMV monitoring/management followed uniform standard practice. Hazards of CMV reactivation at various thresholds were compared. Spline curves were fit over average daily viral load and areas under the curve (AUC) within 1 year were calculated. PTCy and MMF were associated with an increased risk of early (day ≤100) CMV reactivation ≥250 IU/mL after multivariate adjustment. The viral load AUC at 1 year was highest with MMF (mean difference = 0.125 units vs MTX group) and similar between PTCy and MTX (mean difference = 0.016 units vs MTX group). CMV disease risk was similar across groups. There was no interaction between GVHD prophylaxis and CMV reactivation on chronic GVHD risk. Despite PTCy-associated increased risk of early CMV reactivation, the CMV disease risk by 1 year was low in HLA-matched PBSC transplant recipients. In contrast, MMF was associated with higher overall CMV viral burden in the 1 year posttransplant. Although different mechanisms of immunosuppressive agents may affect CMV reactivation risk, effective prevention of GVHD may reduce corticosteroid exposure and mitigate infection risk over time.

Fatigue in Hematopoietic Cell Transplantation Survivors: Correlates, Care Team Communication, and Patient-Identified Mitigation Strategies.

With improved survival after hematopoietic cell transplantation (HCT), the number of individuals at risk for persistent or late effects is increasing. The importance of optimizing HCT survivor health and well-being is mounting. Fatigue is a common post-transplantation symptom that impairs quality of life, yet it remains poorly understood and inadequately addressed. Multiple challenges to addressing fatigue exist, including its multidimensional presentation, multiple (often concomitant) causes, patient-clinician communication barriers, and few highly effective, evidence-based interventions that can be readily implemented. To address these challenges, we sought to better describe the impact and potential causes of fatigue in the post-transplantation setting, fatigue-related communication with clinicians, and the most effective patient-identified mitigation strategies (PIMS) for fatigue. A total of 1703 adult HCT recipients from a single center completed a survey including the Medical Outcomes Survey Short Form-36 (SF-36), PROMIS Fatigue, and other fatigue-related items between July 2017-June 2018. The survey was offered to recipients at their post-transplantation anniversary occurring during this interval. Two independent raters categorized free-text responses about fatigue PIMS. PROMIS Fatigue scores were dichotomized into low (≤55) or high (>55). Associations between high fatigue and participant characteristics and health outcomes were evaluated using the Fisher exact test for categorical variables and the Student 2-sample t test for continuous variables. Among the 1660 respondents with evaluable fatigue scores, 67% underwent allogeneic HCT. The majority of these (n = 1588; 96%) had a malignancy, with hematologic malignancy the most common diagnostic category (n = 1555; 94%). The median time post-transplantation was 11 years (interquartile range, 4 to 20 years). PROMIS item responses indicate that 44% of patients were at least somewhat fatigued and 37% were at least somewhat bothered by it. The mean fatigue score was 50.2 ± 11; 591 patients (36%) had high fatigue, which was associated with worse SF-36 scores across all domains (General Health, Physical Functioning, Emotional Well-being/Mental Health, Social Functioning, Role Limitation due to Physical Health, Role Limitation due to Emotional Health, Vitality [eg, energy], and Bodily Pain). High fatigue also was associated with self-reported chronic graft-versus-host disease, anxiety, depression and sleep problems. Diagnosis of plasma cell disorder and receipt of an autologous transplant were associated with high fatigue (P = .001). Among the 553 individuals who received an autologous transplant, 226 (41%) had multiple myeloma. Compared with the autologous transplant recipients without myeloma group, those with multiple myeloma were significantly more likely to have high fatigue (109 of 226 [48%] versus 118 of 325 [36%]; P < .01). Twenty percent of the patients with high fatigue did not discuss it with their care team. Among the 89 different reasons provided for not discussing it, the most common was "thought they already knew the answer" (n = 21). The 370 survivors with high fatigue who identified at least 1 most effective PIMS generated a total of 639 PIMS. Although the PIMS for fatigue spanned a wide array of strategies, most PIMS were related to sleep/rest (n = 192; 30%) or exercise (n = 139; 22%). Although fatigue is associated with worse HCT survivor-reported outcomes, it is only sometimes discussed with care teams. Survivors identify specific strategies that are most effective. Given its prevalence and impact, clinicians should promote communication about fatigue, treat underlying causes, and recommend sleep/rest and exercise, recognizing that individualized approaches also may be beneficial.

Humoral and Cellular Immune Response to Covid-19 Vaccination in Patients with Chronic Graft-versus-Host Disease on Immunosuppression.

Chronic graft-versus-host disease (cGVHD) and its management with immunosuppressive therapies increase the susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, as well as progression to severe Coronavirus 19 disease (COVID-19). Vaccination against COVID-19 is strongly recommended, but efficacy data are limited in this patient population. In this study, responses to COVID-19 vaccination were measured at 3 time points-after the initial vaccine series, before the third dose, and after the third dose-in adults with cGVHD receiving immunosuppressive therapy. Humoral response was measured by quantitative anti-spike antibody and neutralizing antibody levels. Anti-nucleocapsid antibody levels were measured to detect natural infection. T cell response was evaluated by a novel immunosequencing technique combined with immune repertoire profiling from cryopreserved peripheral blood mononuclear cell samples. Present or absent T cell responses were determined by the relative proportion of unique SARS-CoV-2-associated T cell receptor sequences ("breadth") plus clonal expansion of the response ("depth") compared with those in a reference population. Based on both neutralizing antibody and T cell responses, patients were categorized as vaccine responders (both detected), nonresponders (neither detected), or mixed (one but not both detected). Thirty-two patients were enrolled for the initial series, including 17 (53%) positive responders, 7 (22%) mixed responders, and 8 (25%) nonresponders. All but one patient categorized as mixed responders had humoral responses while lacking T cell responses. No statistical differences were observed in patient characteristics among the 3 groups of patients categorized by immune response, although sample sizes were limited. Significant positive correlations were observed between the robustness of cellular and humoral responses after the initial series. Among the 20 patients with paired samples (pre- and post-third dose), a third vaccination resulted in increased neutralizing antibody titers. cGVHD worsened in 10 patients (26%; 6 after the initial series and 4 after the third dose), necessitating escalation of immunosuppressive doses in 5 patients, although 4 had been tapering immunosuppression and 5 had already worsening cGVHD at the time of vaccination, and a clear association between COVID-19 vaccination and cGVHD could not be drawn. Among the patients with cGVHD on immunosuppressive therapy, 72% demonstrated a neutralizing antibody response after a 2-dose primary COVID-19 vaccination, two-thirds of whom also developed a T cell response; 25% had neither a humoral nor a T cell response. A third dose further amplified the antibody response.

Neuropathy and Muscle Cramps in Autologous and Allogeneic Hematopoietic Cell Transplantation Survivors.

Although autologous and allogeneic hematopoietic cell transplantation are used to treat hematologic diseases, they are associated with high morbidity and mortality. The goal of this cross-sectional study was to describe the incidence, characteristics, severity and clinical correlates of neuropathy and muscle cramps, as self-reported by hematopoietic cell transplantation survivors. We included all respondents to a survey conducted July 1, 2020, to June 30, 2021. Surveys were completed online or on-paper according to participants' preferences; they received one reminder if no survey was received 1 month after distribution. Statistics are primarily descriptive comparing subgroups of patients. Of 4641 potentially eligible patients, 1745 responded and are included in the analysis. Participants (615 [35%] autologous, 1130 [65%] allogeneic) were a median age of 64.1 years (interquartile range [IQR] 55.2-70.8) and surveyed at a median of 11 years (IQR 4-21) after their most recent transplantation. Neuropathy symptoms were reported by 65% of autologous recipients, 66% of allogeneic transplant recipients with current chronic graft versus host disease (GVHD), and 45% of allogeneic recipients who never developed chronic GVHD. Muscle cramps were reported by 56% of autologous recipients, and 52% of allogeneic recipients and were rated as "very painful" by nearly half of patients who experienced them. These results suggest that neuropathy symptoms and muscle cramps are much more prevalent among survivors after hematopoietic cell transplantation than previously recognized. Better approaches for prevention and treatment of these bothersome complications are needed.

Long-term patient-reported neurocognitive outcomes in adult survivors of hematopoietic cell transplant.

Survivors of hematopoietic cell transplant (HCT) are at risk for neurocognitive impairments, which can negatively affect quality of life. Given limited studies, we aimed to describe the neurocognitive outcomes in a cohort of long-term adult HCT survivors. Eligible survivors (age ≥21 years at HCT and alive ≥2 years following HCT) completed a 60-question survey of neurocognitive function and quality of life, which included the Neuro-Quality of Life Cognitive Function Short Form (Neuro-QoL) and the Childhood Cancer Survivor Study Neurocognitive Questionnaire (NCQ). Analyses of risk factors included univariate comparisons and multivariable logistic regression. Survivors (n = 1861, 47.7% female, 65.6% allogeneic HCT) were surveyed at a median age of 64.2 years (interquartile range [IQR], 56.8-70.5) and a median 12.0 years (IQR, 6.0-21.0) from HCT. Survivors reported average Neuro-QoL scores (50.0 allogeneic; 49.2 autologous survivors) compared with an expected mean of 50 in the general population. On the NCQ, 17.4% to 31.2% of survivors reported impairments (Z-score >1.28) in task efficiency, memory, emotional regulation, or organization, compared with an expected 10% in the general population (all P < .01). In multivariable regression analyses, impaired Neuro-QoL (T-score <40) was independently associated with hearing issues (odds ratio [OR], 2.13; 95% confidence interval [CI], 1.46-3.10) and sleep impairment (OR, 4.41; 95% CI, 2.80-6.94) among allogeneic survivors, with comparable associations in autologous survivors. Overall, long-term adult HCT survivors reported average cognitive quality of life compared with the general population. Subsets of survivors with hearing issues and sleep impairments were more likely to report lower quality of life and impaired neurocognitive function, which may facilitate targeted monitoring or interventions following HCT.

Naive T-Cell Depletion to Prevent Chronic Graft-Versus-Host Disease.

PURPOSE: Graft-versus-host disease (GVHD) causes morbidity and mortality following allogeneic hematopoietic cell transplantation. Naive T cells (TN) cause severe GVHD in murine models. We evaluated chronic GVHD (cGVHD) and other outcomes in three phase II clinical trials of TN-depletion of peripheral blood stem-cell (PBSC) grafts. METHODS: One hundred thirty-eight patients with acute leukemia received TN-depleted PBSC from HLA-matched related or unrelated donors following conditioning with high- or intermediate-dose total-body irradiation and chemotherapy. GVHD prophylaxis was with tacrolimus, with or without methotrexate or mycophenolate mofetil. Subjects received CD34-selected PBSC and a defined dose of memory T cells depleted of TN. Median follow-up was 4 years. The primary outcome of the analysis of cumulative data from the three trials was cGVHD. RESULTS: cGVHD was very infrequent and mild (3-year cumulative incidence total, 7% [95% CI, 2 to 11]; moderate, 1% [95% CI, 0 to 2]; severe, 0%). Grade III and IV acute GVHD (aGVHD) occurred in 4% (95% CI, 1 to 8) and 0%, respectively. The cumulative incidence of grade II aGVHD, which was mostly stage 1 upper gastrointestinal GVHD, was 71% (95% CI, 64 to 79). Recipients of matched related donor and matched unrelated donor grafts had similar rates of grade III aGVHD (5% [95% CI, 0 to 9] and 4% [95% CI, 0 to 9]) and cGVHD (7% [95% CI, 2 to 13] and 6% [95% CI, 0 to 12]). Overall survival, cGVHD-free, relapse-free survival, relapse, and nonrelapse mortality were, respectively, 77% (95% CI, 71 to 85), 68% (95% CI, 61 to 76), 23% (95% CI, 16 to 30), and 8% (95% CI, 3 to 13) at 3 years. CONCLUSION: Depletion of TN from PBSC allografts results in very low incidences of severe acute and any cGVHD, without apparent excess risks of relapse or nonrelapse mortality, distinguishing this novel graft engineering strategy from other hematopoietic cell transplantation approaches.

Conditioning intensity and peritransplant flow cytometric MRD dynamics in adult AML.

In acute myeloid leukemia (AML), measurable residual disease (MRD) before or after allogeneic hematopoietic cell transplantation (HCT) is an established independent indicator of poor outcome. To address how peri-HCT MRD dynamics could refine risk assessment across different conditioning intensities, we analyzed 810 adults transplanted in first or second remission after myeloablative conditioning (MAC; n = 515) or non-MAC (n = 295) who underwent multiparameter flow cytometry-based MRD testing before as well as 20 to 40 days after allografting. Patients without pre- and post-HCT MRD (MRDneg/MRDneg) had the lowest risks of relapse and highest relapse-free survival (RFS) and overall survival (OS). Relative to those patients, outcomes for MRDpos/MRDpos and MRDneg/MRDpos patients were poor regardless of conditioning intensity. Outcomes for MRDpos/MRDneg patients were intermediate. Among 161 patients with MRD before HCT, MRD was cleared more commonly with a MAC (85 of 104; 81.7%) than non-MAC (33 of 57; 57.9%) regimen (P = .002). Although non-MAC regimens were less likely to clear MRD, if they did, the impact on outcome was greater. Thus, there was a significant interaction between conditioning intensity and "MRD conversion" for relapse (P = .020), RFS (P = .002), and OS (P = .001). Similar findings were obtained in the subset of 590 patients receiving HLA-matched allografts. C-statistic values were higher (indicating higher predictive accuracy) for peri-HCT MRD dynamics compared with the isolated use of pre-HCT MRD status or post-HCT MRD status for prediction of relapse, RFS, and OS. Across conditioning intensities, peri-HCT MRD dynamics improve risk assessment over isolated pre- or post-HCT MRD assessments in patients with AML.

Long-term survival with mixed chimerism in patients with AML and MDS transplanted after conditioning with targeted busulfan, fludarabine, and thymoglobulin.

We evaluated long-term outcome in 40 patients with MDS or AML, transplanted from related or unrelated donors following conditioning with targeted busulfan (Bu, over 4 days), fludarabine (Flu, 120 [n = 23] or 250 [n = 17] mg/m2) and thymoglobulin (THY). Compared to 95 patients conditioned with Bu/Cyclophosphamide (Cy) without THY, BuFluTHY-conditioned patients had lower rates of chronic graft-vs.-host disease (GVHD). Adjusted hazard ratios (HR) for BuFlu(120)THY and BuFlu(250)THY-conditioned patients were 1.60 (95% confidence interval (CI) 0.66-3.86) and 1.87 (0.68-5.11), respectively, for relapse; 0.77 (0.30-1.99) and 1.32 (0.54-3.23) for non-relapse mortality; 0.81 (0.42-1.57) and 1.38 (0.72-2.57) for overall mortality; and 0.78 (0.30-2.05) and 1.62 (0.63-4.41) for relapse or death (failure for relapse-free survival). At one year, 45% of BuFlu(120 or 250)THY-conditioned patients had mixed CD3+ chimerism compared to 0% with BuCy (p < 0.0001). None of 7 patients with long-term mixed chimerism had chronic GVHD; two relapsed, five remained stable mixed chimeras. THY is effective in reducing chronic GVHD, and long-term mixed T-cell chimerism can be compatible with relapse-free survival. However, Thy may also be associated with an increased risk of relapse and, dose-dependent, with non-relapse mortality.

Cancers after HLA-matched related bone marrow transplantation for aplastic anemia.

We analyzed subsequent cancers in 329 patients with aplastic anemia given HLA-matched related marrow grafts. Median follow-up: 26 (range 1-47) years. Conditioning: cyclophosphamide ± antithymocyte globulin; graft-vs.-host disease (GVHD) prevention: methotrexate ± cyclosporine. The long follow-up and homogeneous treatment allowed definitive analyses of incidence, nature, time of onset, and potential causes of cancers. Fifty-three cancers occurred in 46 patients, 42 had solid tumors and 4 blood cancers. Of the 42, 22 had non-melanoma skin and 7 oropharyngeal cancers. The remainder had a spectrum of other cancers including two liver cancers from pre-transplant hepatitis C. The 26-year cumulative incidence (CI) of cancer was 11% and mortality 5%. Excluding non-melanoma skin cancers, the 26-year CI of cancer was 7%. Cancers were 2.03-fold more than expected from SEER data; that number was 1.89-fold after excluding liver cancers. Nearly all cancers developed between 14 and 34 years. Skin and oropharyngeal cancers showed significant association with chronic GVHD, whereby GVHD had resolved in most patients within 7 years of transplantation. Thus, tumors evolved after a lag time of 7-27 years. Other cancers showed no clear associations with chronic GVHD or drugs used for transplantation. Results reemphasize the importance of preventing chronic GVHD.