Allogeneic Hematopoietic Cell Transplantation in the Outpatient Setting

Conditioning with fludarabine and low-dose total-body irradiation before allogeneic hematopoietic cell transplantation (HCT) enabled treating older or medically infirm patients with advanced hematologic malignancies in the outpatient setting. Between December 1997 and June 2017, 1037 patients with hematologic malignancies received peripheral blood stem cell (PBSC) grafts from HLA-matched or 1 HLA antigen/allele-mismatched related or unrelated donors. Median age was 58 (range, 18 to 80) years. Serious comorbidities with Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI) scores ≥3 were present in 52% of patients. We found that 47% of patients were either never hospitalized or only had an overnight hospital stay for infusion of late-arriving PBSCs while 53% were admitted for a median of 6 days. Main reasons for admission were infection, fever, graft-versus-host disease, and regimen-related toxicity. Two thirds of admissions occurred within 3 weeks of HCT. The 5-year risk of nonrelapse mortality (NRM) was 26% among hospitalized patients and 13% among nonhospitalized patients. Significant risk factors for hospitalization included unrelated transplants, 1 HLA antigen-mismatched transplant, high HCT-CI scores, and diagnosis of nonmyeloma malignancies. Significant risk factors for NRM were hospitalization, older age, unrelated transplants, and high HCT-CI scores. Ambulatory allogeneic HCT is feasible and safe.     

Outcomes of Lung Transplantation after Allogeneic Hematopoietic Stem Cell Transplantation

Other than lung transplantation (LT), no specific therapies exist for end-stage lung disease resulting from hematopoietic stem cell transplantation (HCT)-related complications, such as bronchiolitis obliterans syndrome (BOS). We report the indications and outcomes in patients who underwent LT after HCT for hematologic disease from a retrospective case series at our institution and a review of the medical literature. We identified a total of 70 cases of LT after HCT, including 9 allogeneic HCT recipients from our institution who underwent LT between 1990 and 2010. In our cohort, the median age was 16 years (range, 10 to 35 years) at the time of HCT and 34 years (range, 17 to 44 years) at the time of LT, with a median interval between HCT and LT of 10 years (range, 2.9 to 27 years). Indications for LT-included pulmonary fibrosis (n = 4), BOS (n = 3), interstitial pneumonitis related to graft-versus-host disease (GVHD) (n = 1), and primary pulmonary hypertension (n = 1). Median survival was 49 months (range, 2 weeks to 87 months), and 1 patient remains alive at more than 3 years after LT. Survival at 1 year and 5 years after LT was 89% and 37%, respectively. In the medical literature between 1992 and July 2013, we identified 20 articles describing 61 cases of LT after HCT from various centers in the United States, Europe, and Asia. Twenty-six of the 61 cases (43%) involved patients age <18 years at the time of LT. BOS and GVHD of the lung were cited as the indication for LT in the majority of cases (80%; n = 49), followed by pulmonary fibrosis and interstitial lung disease (20%; n = 12). In publications reporting 3 or more cases with a follow-up interval ranging from the immediate postoperative period to 16 years, the survival rate was 71% (39 of 55). Most deaths were attributed to long-term complications of the lung allograft, including infections and BOS. Two deaths were related to recurrent or relapsed hematologic malignancy. LT can prolong survival in some patients who suffer from end-stage pulmonary complications after HCT. Patient factors that likely improve the chances of a good long-term outcome include young age, at least 2 years post-HCT free of relapse from the original hematologic malignancy, and lack of other end-organ dysfunction or manifestations of chronic GVHD that require treatment with immunosuppressive agents.     

Second Solid Cancers after Allogeneic Hematopoietic Cell Transplantation Using Reduced-Intensity Conditioning

We examined risk of second solid cancers after allogeneic hematopoietic cell transplantation (AHCT) using reduced-intensity/nonmyeloablative conditioning (RIC/NMC). RIC/NMC recipients with leukemia/myelodysplastic syndrome (MDS) (n = 2833) and lymphoma (n = 1436) between 1995 and 2006 were included. In addition, RIC/NMC recipients 40 to 60 years of age (n = 2138) were compared with patients of the same age receiving myeloablative conditioning (MAC, n = 6428). The cumulative incidence of solid cancers was 3.35% at 10 years. There was no increase in overall cancer risk compared with the general population (leukemia/MDS: standardized incidence ratio [SIR] .99, P = 1.00; lymphoma: SIR .92, P = .75). However, risks were significantly increased in leukemia/MDS patients for cancers of lip (SIR 14.28), tonsil (SIR 8.66), oropharynx (SIR 46.70), bone (SIR 23.53), soft tissue (SIR 12.92), and vulva (SIR 18.55) and skin melanoma (SIR 3.04). Lymphoma patients had significantly higher risks of oropharyngeal cancer (SIR 67.35) and skin melanoma (SIR 3.52). Among RIC/NMC recipients, age >50 years was the only independent risk factor for solid cancers (hazard ratio [HR] 3.02, P < .001). Among patients ages 40 to 60 years, when adjusted for other factors, there was no difference in cancer risks between RIC/NMC and MAC in leukemia/MDS patients (HR .98, P = .905). In lymphoma patients, risks were lower after RIC/NMC (HR .51, P = .047). In conclusion, the overall risks of second solid cancers in RIC/NMC recipients are similar to the general population, although there is an increased risk of cancer at some sites. Studies with longer follow-up are needed to realize the complete risks of solid cancers after RIC/NMC AHCT.     

Impact of Lung Function on Bronchiolitis Obliterans Syndrome and Outcome after Allogeneic Hematopoietic Cell Transplantation with Reduced-Intensity Conditioning

Lung function deterioration contributes to treatment-related morbidity and mortality in patients after allogeneic hematopoietic cell transplantation (allo-HCT). Better understanding of impaired lung function including bronchiolitis obliterans syndrome (BOS) as chronic manifestation of graft-versus-host disease (GVHD) might improve outcomes of patients after allo-HCT.To detect early pulmonary function test abnormalities associated with BOS incidence and outcome after allo-HCT, we performed a retrospective analysis of homogenous-treated 445 patients (median age, 61.9 years; range, 19 to 76 years) with a reduced intensity/toxicity conditioning protocol. The cumulative incidence of BOS was 4.1% (95% confidence interval [CI], 2.6 to 6.4) at 1 year and 8.6% (95% CI, 6.3 to 11.6) at 5 years after allo-HCT with a median follow-up of 43.2 months (range, 3.3 to 209 months). In multivariate analysis, pre-existence of moderate small airway disease reflected by decreased midexpiratory flows before allo-HCT was associated with increased risk for BOS development. In addition, severe small airway disease before allo-HCT and combined restrictive/obstructive lung disease at day +100 after allo-HCT were associated with higher risk for nonrelapse mortality (NRM) due mainly to pulmonary cause of death.In summary, we identified novel pulmonary function test abnormalities prior and after allo-HCT associated with BOS development and NRM. These findings might help to identify a risk population and result in personalized GVHD prophylaxis and preventive or early therapeutic interventions.     

Comparison of Two Doses of Antithymocyte Globulin in Reduced-Intensity Conditioning Allogeneic Hematopoietic Stem Cell Transplantation

The appropriate dose of antithymocyte globulin (ATG) to be used in reduced-intensity conditioning (RIC) allogeneic hematopoietic stem cell transplantation (allo-HSCT) is yet to be determined. We retrospectively analyzed the outcomes of patients who underwent unrelated or mismatch related RIC allo-HSCT for hematologic malignancies and received r-ATG (4.5 mg/kg, 141 patients) versus R-ATG (6 mg/kg, 216 patients). There was a higher incidence of cytomegalovirus (P < .001) and Epstein-Barr virus viremia (P =.03) in the R-ATG group than in the r-ATG group. The cumulative incidences of acute graft-versus-host disease (aGVHD) grades II to IV at day 180 in the r-ATG and R-ATG groups were 59% and 44% (P = .006) and grades III to IV 20% and 12% (P = .029), respectively. In multivariable models adjusting for disease diagnosis, the risk of aGVHD grades III to IV did not reach statistical significance (P = .087). The respective cumulative incidences of chronic GVHD in the r-ATG and R-ATG groups were 26% and 15% (P = .10), respectively. There were no significant differences in relapse rate (P = .24), nonrelapse mortality (P = .96), progression-free survival (P = .24), overall survival (P = .70), and GVHD-free relapse-free survival (P = .24). In this retrospective analysis, aGVHD incidence was higher in those treated with r-ATG compared with R-ATG, but this did not translate into significant differences of clinical outcome. Given the increasing use of RIC allo-HSCT for treating malignant hematologic conditions, the correct dose and schedule of ATG administration should be defined by prospective randomized controlled trials.     

Donor Chimerism Early after Reduced-Intensity Conditioning Hematopoietic Stem Cell Transplantation Predicts Relapse and Survival

The impact of early donor cell chimerism on outcomes of T cell–replete reduced-intensity conditioning (RIC) hematopoietic stem cell transplantation (HSCT) is ill defined. We evaluated day 30 (D30) and 100 (D100) total donor cell chimerism after RIC HSCT undertaken between 2002 and 2010 at our institution, excluding patients who died or relapsed before D30. When available, donor T cell chimerism was also assessed. The primary outcome was overall survival (OS). Secondary outcomes included progression-free survival (PFS), relapse, and nonrelapse mortality (NRM). We evaluated 688 patients with hematologic malignancies (48% myeloid and 52% lymphoid) and a median age of 57 years (range, 18 to 74) undergoing RIC HSCT with T cell–replete donor grafts (97% peripheral blood; 92% HLA-matched), with a median follow-up of 58.2 months (range, 12.6 to 120.7). In multivariable analysis, total donor cell and T cell chimerism at D30 and D100 each predicted RIC HSCT outcomes, with D100 total donor cell chimerism most predictive. D100 total donor cell chimerism <90% was associated with increased relapse (hazard ratio [HR], 2.54; 95% confidence interval [CI], 1.83 to 3.51; P < .0001), impaired PFS (HR, 2.01; 95% CI, 1.53 to 2.65; P < .0001), and worse OS (HR, 1.50; 95% CI, 1.11 to 2.04, P = .009), but not with NRM (HR, .76; 95% CI, .44 to 2.27; P = .33). There was no additional utility of incorporating sustained D30 to D100 total donor cell chimerism or T cell chimerism. Low donor chimerism early after RIC HSCT is an independent risk factor for relapse and impaired survival. Donor chimerism assessment early after RIC HSCT can prognosticate for long-term outcomes and help identify high-risk patient cohorts who may benefit from additional therapeutic interventions.     

Outcomes of Allogeneic Hematopoietic Cell Transplantation in Patients with Dyskeratosis Congenita

We describe outcomes after allogeneic transplantation in 34 patients with dyskeratosis congenita who underwent transplantation between 1981 and 2009. The median age at transplantation was 13 years (range, 2 to 35). Approximately 50% of transplantations were from related donors. Bone marrow was the predominant source of stem cells (24 of 34). The day-28 probability of neutrophil recovery was 73% and the day-100 platelet recovery was 72%. The day-100 probability of grade II to IV acute GVHD and the 3-year probability of chronic graft-versus-host disease were 24% and 37%, respectively. The 10-year probability of survival was 30%; 14 patients were alive at last follow-up. Ten deaths occurred within 4 months from transplantation because of graft failure (n = 6) or other transplantation-related complications; 9 of these patients had undergone transplantation from mismatched related or from unrelated donors. Another 10 deaths occurred after 4 months; 6 of them occurred more than 5 years after transplantation, and 4 of these were attributed to pulmonary failure. Transplantation regimen intensity and transplantations from mismatched related or unrelated donors were associated with early mortality. Transplantation of grafts from HLA-matched siblings with cyclophosphamide-containing nonradiation regimens was associated with early low toxicity. Late mortality was attributed mainly to pulmonary complications and likely related to the underlying disease.     

Viral Respiratory Tract Infections in Allogeneic Hematopoietic Stem Cell Transplantation Recipients in the Era of Molecular Testing

Viral respiratory tract infection (vRTI) is a significant cause of morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study aimed to assess the epidemiologic characteristics, risk factors, and outcomes of vRTI occurring in the period from conditioning to 100 days after allo-HSCT in the era of molecular testing. This study was a retrospective record review of patients who underwent allo-HSCT at Royal Melbourne Hospital between January 2010 and December 2015. Symptomatic patients were tested using respiratory multiplex polymerase chain reaction (PCR). Logistic regression and Kaplan-Meier analysis were used to identify risk factors for vRTI and the risk of death or intensive care unit (ICU) admission, respectively. A total of 382 patients were reviewed, and 65 episodes of vRTI were identified in 56 patients (14.7%). Rhinovirus accounted for the majority of infections (69.2%). The majority of episodes presented initially with upper respiratory tract infection (58.5%), with 28.9% of them progressing to lower respiratory tract infection. Eleven episodes (16.9%) were associated with ICU admission. There were no deaths directly due to vRTI. Previous autologous HSCT was associated with an increased risk of vRTI (odds ratio, 2.1; 95% confidence interval, 1.0 to 4.1). The risks of death (P?=?.47) or ICU admission (P?=?.65) were not significantly different by vRTI status. vRTI is common in the first 100 days after allo-HSCT and is associated with ICU admission.     

Impact of Hyperferritinemia on the Outcome of Reduced-Intensity Conditioning Allogeneic Hematopoietic Cell Transplantation for Lymphoid Malignancies

Hyperferritinemia has been associated with adverse outcomes after allogeneic hematopoietic cell transplantation (allo-HCT) with myeloablative conditioning. However, its characteristics and impact on the outcome in the reduced-intensity conditioning (RIC) and in the lymphoid malignancy settings are far from clear. The study includes 201 adult patients undergoing allo-HCT with RIC (allo-RIC) for lymphoid malignancies with a median follow-up for survivors of 52 months (range, 3 to 123). Median serum ferritin level at allo-RIC was 379 ng/mL (range, 4 to 10,790). In the multivariate analysis, patients with hyperferritinemia at transplantation (>399 ng/mL) showed lower 4-year overall survival (hazard ratio [HR], 1.8 [95% confidence interval {CI}, 1.2 to 2.8]; P = .008), higher nonrelapse mortality (NRM) (HR, 1.8 [95% CI, 1.1 to 3.2]; P = .03), and higher infection-related mortality (HR, 2.3 [95% CI, 1.1 to 4.8]; P = .02) than patients without hyperferritinemia. Neutrophil and platelet engraftment and 100-day NRM were similar between both groups. The adverse outcome associated with hyperferritinemia seemed higher in patients without major comorbidities and was not influenced by the elevation of acute phase reactants. Our results indicate that high ferritin levels at HCT are associated with an adverse outcome after allo-RIC in patients with lymphoid malignancies.     

Analysis of Donor and Recipient ABO Incompatibility and Antibody-Associated Complications after Allogeneic Stem Cell Transplantation with Reduced-Intensity Conditioning

Allogeneic hematopoietic stem cell transplantation (HSCT) can be performed across the ABO blood group barrier. The impact of ABO incompatibility on clinical outcome is controversial. A retrospective analysis of 310 patients who underwent HSCT with reduced-intensity conditioning between 1998 and 2011 was performed to investigate the frequency and clinical implications of anti-RBC antibodies in passenger lymphocyte syndrome (PLS) after minor ABO mismatch (mm), persistent or recurring recipient type ABO antibodies (PRABO) after major ABO mm HSCT, and autoimmune hemolytic anemia (AIHA). Transplantation characteristics and clinical outcome were analyzed by univariate and multivariate analysis for groups with or without anti-RBC antibodies. ABO blood group incompatibility did not affect clinical outcome despite an increased requirement of blood transfusion. Twelve patients with AIHA, 6 patients with PLS, and 12 patients with PRABO post-HSCT were identified. AIHA did not affect overall survival (OS) or transplant-related mortality (TRM), but patients with AIHA had a lower incidence of grades II to IV acute graft-versus-host disease (P = .05). OS in the PLS group was 0% compared with 61% in the whole group receiving minor ABO mm transplants (P < .001). Comparing PRABO patients with those receiving a major ABO mm HSCT, the OS was 17% versus 73% (P = .002) and TRM was 50% versus 21% (P = .03). At our center, PLS after minor ABO mm and PRABO antibodies after major ABO mm HSCT are significant risk factors for decreased OS and TRM. Our results suggest that occurrence of unexpected ABO antibodies after HSCT warrant a wider investigation individual to find the underlying cause.     

Double-Expressor Lymphoma Is Associated with Poor Outcomes after Allogeneic Hematopoietic Cell Transplantation

Double-expressor lymphoma (DEL) is a diffuse large B cell lymphoma that exhibits co-expression of MYC and BCL2 proteins by immunohistochemistry. Patients with double-expressor lymphoma have a poor prognosis after standard chemoimmunotherapy or after high-dose chemotherapy with autologous transplantation, but the prognostic impact of DEL after allogeneic hematopoietic cell transplantation has not been well characterized. We retrospectively analyzed 60 consecutive patients with de novo diffuse large B cell lymphoma or transformed follicular lymphoma who underwent allogeneic transplantation at our center and had available immunohistochemistry data. Thirty-seven patients (62%) had DEL. The 2-year progression-free and overall survival rates were lower in patients with DEL than in those without DEL (20% versus 78%; overall P?<.001 and 46% versus 77%; overall P?=?.016, respectively). The cumulative incidence of disease progression at 2 years was higher in patients with DEL (60% versus 13%; overall P?=?.005). The cumulative incidence of nonrelapse mortality did not differ statistically in the 2 groups. Even in patients with DEL and chemosensitive disease at transplantation, the 2-year progression-free survival rate was only 27% due to early disease progression. Multivariate analysis showed associations between DEL and increased risks of progression-free survival events (hazard ratio [HR], 4.58; 95% confidence interval [CI], 2.07-10.2; P?<.001), overall mortality (HR, 2.29; 95% CI, 1.03-5.09; P?=?.042) and disease progression (HR, 3.60; 95% CI, 1.38-9.44; P?=?.009). Patients with DEL had poor outcomes after allogeneic transplantation. Innovative strategies are needed to improve outcomes in this population.     

Predictors and Impact of Thirty-Day Readmission on Patient Outcomes and Health Care Costs after Reduced-Toxicity Conditioning Allogeneic Hematopoietic Cell Transplantation

Thirty-day readmission (30-DR) has become an important quality-of-care measure. Allogeneic hematopoietic cell transplantation (allo-HCT) presents a medical setting with higher readmission rates. We analyzed factors affecting 30-DR and its impact on patient outcomes and on health care costs in 91 patients who underwent reduced-toxicity conditioning (RTC) allo-HCT with fludarabine and busulfan. The patient cohort was divided into 2: the readmission group (R-gp) or the no-readmission group (NR-gp). Overall, 38% (n = 35) required readmission with a median time to readmission of 14 days. In multivariate analysis, only documented infection during the index admission predicted 30-DR, P = .01. With a median follow-up of 18 months (range, 1 to 69) for surviving patients, the 2-year overall survival was 49% and 58% in the R-gp and NR-gp respectively, P = .48. The 1-year nonrelapse mortality in R-gp and NR-gp was 18% and 13% respectively, P = .43. The median post-transplantation hospital charges in the R-gp and NR-gp were $85,115 (range, $32,015 to $242,519) and $45,083 (range, $10,715 to $485,456), P = .0002. In conclusion, only documented infections during the index hospitalization influenced 30-DR after RTC allo-HCT. Although 30-DR did not adversely affect mortality or survival, it was associated with significantly increased 100-day post-transplantation hospital charges, thus supporting its role as a quality-of-care measure in allo-HCT patients.     

Comparison of Outcomes of Allogeneic Hematopoietic Cell Transplantation for Multiple Myeloma Using Three Different Conditioning Regimens

Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative therapy for patients with multiple myeloma, as it provides a graft-versus-myeloma effect alongside a myeloma-free graft. Although reduced-intensity conditioning regimens decrease nonrelapse mortality (NRM), there is a paucity of data with regard to the ideal conditioning regimen in myeloma. We conducted a retrospective comparison of 3 different preparative regimens used for allo-HCT for multiple myeloma at our institution in recent clinical trials: busulfan/fludarabine (BuFlu), fludarabine/melphalan 100 mg/m² (FM100), and fludarabine/melphalan 140 mg/m² (FM140). NRM, progression-free survival (PFS) at 3 years, and overall survival (OS) at 3 years were the primary endpoints. Secondary endpoints included time to engraftment, and the incidence of grades II through IV acute graft-versus-host disease and chronic graft-versus-host disease. A total of 73 patients received allo-HCT with these regimens. NRM at 3 years was seen in 3 (21%), 5 (28%), and 6 (24%) patients in the BuFlu, FM100, and FM140 groups, respectively. Three-year PFS in the BuFlu, FM100, and FM140 groups was 16% (hazard ratio [HR], 1.2; 95% confidence interval [CI], 0.6 to 2.1), 26% (HR, 0.6; 95% CI, 0.3 to 1.2), and 11% (reference), respectively. Three-year OS in the BuFlu, FM100, and FM140 groups was 39% (HR, 1.1; 95% CI, 0.5 to 2.2), 43% (HR, 0.7; 95% CI, 0.3 to 1.4), and 32% (reference), respectively. High-risk cytogenetics and relapsed disease prior to allo-HCT were found to be independent predictors of inferior OS on multivariate analysis, with a HR of 2.1 (P = .02) and 2.6 (P = .004), respectively. In contrast, the preparative regimen did not emerge as a predictor of PFS or OS. Durable clinical remission can be achieved in 11% to 25% of patients with multiple myeloma with the use of allo-HCT without any significant difference in the safety or efficacy of the conditioning regimen. High-risk cytogenetics and relapsed disease prior to transplant were associated with inferior PFS and OS.     

Radioimmunotherapy in Combination with Reduced-Intensity Conditioning for Allogeneic Hematopoietic Cell Transplantation in Patients with Advanced Multiple Myeloma

Radioimmunotherapy (RIT) has the potential to reduce the incidence of relapse after allogeneic hematopoietic cell transplantation (allo-HCT) in patients with advanced-stage multiple myeloma (MM). In this study, we evaluated the efficacy of RIT in combination with chemotherapy-based reduced-intensity conditioning (RIC). RIT was based on the coupling of an anti-CD66 antibody to the beta emitter 188-rhenium (188-re) for targeted bone marrow irradiation. Between 2012 and 2018, 30 patients with MM, most of them heavily pretreated with various therapies including proteasome inhibitors, immunomodulatory drugs, anti-CD38 antibodies, and autologous hematopoietic cell transplantation (auto-HCT), were treated with a RIT-RIC combination before allo-HCT. In addition to a fludarabine plus melphalan- or treosulfan-based RIC, a median dose of 18.1 Gy (interquartile range [IQR], 14.6 to 24.1 Gy) was applied to the bone marrow. After a median duration of follow-up for surviving patients of 2.1 years (IQR, 1.3 to 3.0 years), the 2-year progression-free survival and overall survival rates were 43% (95% confidence interval [CI], 26% to 73%) and 55% (95% CI, 38% to 79%), respectively. The 2-year nonrelapse mortality and cumulative incidence of progression were 17% (95% CI, 3% to 30%) and 46% (95% CI, 25% to 67%), respectively. Renal toxicity and mucositis were the most frequent extramedullary side effects. In conclusion, the addition of RIT to RIC was safe and feasible and resulted in promising outcomes compared with those previously reported for RIC-based allo-HCT without the addition of RIT in patients with relapsed/refractory MM. Nevertheless, despite the addition of RIT, relapse after allo-HCT remained a major determinant of therapeutic failure. Therefore, the development of novel RIT strategies (eg, dual targeting strategies or combinations with adapter chimeric antigen receptor T cell-based therapies) is needed.     

Outcomes of Children with Hemophagocytic Lymphohistiocytosis Given Allogeneic Hematopoietic Stem Cell Transplantation in Italy

We report on 109 patients with hemophagocytic lymphohistiocytosis (HLH) undergoing 126 procedures of allogeneic hematopoietic stem cell transplantation (HSCT) between 2000 and 2014 in centers associated with the Italian Pediatric Hematology Oncology Association. Genetic diagnosis was FHL2 (32%), FHL3 (33%), or other defined disorders known to cause HLH (15%); in the remaining patients no genetic abnormality was found. Donor for first transplant was an HLA-matched sibling for 25 patients (23%), an unrelated donor for 73 (67%), and an HLA-partially matched family donor for 11 children (10%). Conditioning regimen was busulfan-based for 61 patients (56%), treosulfan-based for 21 (20%), and fludarabine-based for 26 children (24%). The 5-year probabilities of overall survival (OS) and event-free survival (EFS) were 71% and 60%, respectively. Twenty-six patients (24%) died due to transplant-related causes, whereas 14 (13%) and 10 (9%) patients experienced graft rejection and/or relapse, respectively. Twelve of 14 children given a second HSCT after graft failure/relapse are alive and disease-free. Use of HLA-partially matched family donors was associated with higher risk of graft failure and thus with lower EFS (but not with lower OS) in multivariable analysis. Active disease at transplantation did not significantly affect prognosis. These data confirm that HSCT can cure most HLH patients, active disease not precluding successful transplantation. Because in HLH patients HLA-haploidentical HSCT performed through CD34⁺ cell positive selection was found to be associated with poor sustained engraftment of donor cells, innovative approaches able to guarantee a more robust engraftment are warranted in patients given this type of allograft.     

CD34+ Cell Selection versus Reduced-Intensity Conditioning and Unmodified Grafts for Allogeneic Hematopoietic Cell Transplantation in Patients Age >50 Years with Acute Myelogenous Leukemia and Myelodysplastic Syndrome

Reduced-intensity conditioning (RIC) and T cell depletion (TCD) through CD34⁺ cell selection without the use of post-transplantation immunosuppression are 2 strategies used to reduce nonrelapse mortality (NRM) in older patients after allogeneic hematopoietic cell transplantation (allo-HCT). To compare the efficacy of the RIC and TCD approaches, we evaluated the outcomes of patients age >50 years with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS) who underwent allo-HCT from an HLA-matched donor with one of these strategies. Baseline characteristics were comparable in the patients receiving TCD (n?=?204) and those receiving RIC (n?=?151), except for a higher proportion of unrelated donors (68% versus 40%; P?<?.001) and a higher comorbidity burden (Hematopoietic Cell Transplantation Comorbidity Index [HCT-CI] ≥3: 51% versus 38%; P?<?.001) in the TCD cohort. Analysis of outcomes at 3 years showed a higher chronic graft-versus-host disease (GVHD)/relapse-free survival (CRFS) (51% versus 7%; P?<?.001), lower incidences of grade II-IV acute GVHD (18% versus 46% at day +180) and chronic GVHD (6% versus 55% at 3 years; P?<?.001), and a lower incidence of relapse (19% versus 33% at 3 years; P?=?.001) in the TCD group compared with the RIC group. Relapse-free survival (RFS), overall survival (OS), and NRM were similar in the 2 groups. Combining transplantation approach (RIC versus TCD) and comorbidity burden (HCT-CI 0-2 versus ≥3), patients with an HCT-CI score of 0-2 seemed to benefit from the TCD approach. In conclusion, in this retrospective study, the use of a CD34⁺ cell-selected graft and a myeloablative conditioning regimen was associated with higher CRFS and similar RFS and OS compared with unmodified allo-RIC in patients age >50 years with AML and MDS.     

Assessment of the Hematopoietic Cell Transplantation Comorbidity Index in Non-Hodgkin Lymphoma Patients Receiving Reduced-Intensity Allogeneic Hematopoietic Stem Cell Transplantation

The hematopoietic cell transplantation comorbidity index (HCT-CI), a weighted index of 17 pretransplantation comorbidities, has been validated in nonmyeloablative and myeloablative allogeneic hematopoietic stem cell transplantation (HSCT) studies, but it has not been specifically tested in patients with non-Hodgkin lymphoma (NHL) receiving reduced-intensity conditioning (RIC). We performed a retrospective analysis to assess the impact of the HCT-CI on outcomes of NHL patients treated with HSCT relative to treatment-related mortality (TRM), disease-related mortality (DRM), with a specific emphasis on overall survival (OS). Individual pretransplantation and disease-related factors also were analyzed with HCT-CI relative to their impact on OS. All patients were uniformly treated with an identical pretransplantation induction regimen and an identical RIC regimen (cyclophosphamide [Cy]/fludarabine [Flu]), and received T cell–replete allografts from HLA-matched siblings. The analysis included 63 NHL patients with a median HCT-CI score of 2 (range, 0 to 11). The HCT-CI (0 to 2 comorbidities vs 3+ comorbidities) demonstrated a potential association with TRM, but not with DRM, at 100 days (4.5% vs 26.3%) and at 1 year (13.6% vs 36.8%) posttransplantation. The factor most strongly associated with OS was response to pretransplantation chemotherapy (P = .0001), based on a composite measure. In a Cox model, pretransplantation chemotherapy response remained the most important factor (P < .0001) relative to OS, and there was a trend (P = .056) toward HCT-CI adding predictive value for OS. Although HCT-CI may be useful for predicting TRM, our data further underscore the importance of response to chemotherapy before transplantation as a predictor of overall transplantation outcome in NHL patients being considered for RIC allogeneic HSCT.     

Preconditioning Absolute Lymphocyte Count and Transplantation Outcomes in Matched Related Donor Allogeneic Hematopoietic Stem Cell Transplantation Recipients with Reduced-Intensity Conditioning and Antithymocyte Globulin Treatment

The integration of antithymocyte globulin (ATG) into therapy has significantly reduced the incidence of graft-versus-host disease (GVHD) and is being actively used in allogeneic hematopoietic stem cell transplantation (allo-HSCT). The ATG dosage is determined by the recipient's body weight, but some insist that this approach does not reflect the actual target of ATG. In this respect, weight-based dosing may lead to ATG overdose, particularly in recipients with a relatively low absolute lymphocyte count (ALC). We retrospectively analyzed 84 patients with acute leukemia or myelodysplastic syndrome who underwent matched related donor (MRD) allo-HSCT with reduced-intensity conditioning (RIC) at a single institution. Patients were dichotomized according to the ALC measured on the first day of conditioning (day -7) to investigate the associations of the ALC with GVHD and survival outcomes. The median duration of follow-up was 29 months. The preconditioning ALC was closely correlated with the ALC at the first ATG administration (day -3). The cumulative incidences of both acute GVHD and chronic GVHD were significantly lower in the preconditioning ALC <500/μL group compared with the ALC ≥500/μL group. There was no significant difference in disease relapse incidence between the 2 groups; however, mortality was significantly higher in the ALC <500/μL group. Multivariate analysis including disease status, modified European Blood and Marrow Transplantation score, and preconditioning ALC (≥500/μL versus <500/μL) identified disease status and ALC as being independently associated with overall survival (OS). In particular, infection was the most common cause of death in the ALC <500/μL group. Our data suggest that uniform weight-based ATG dosing in MRD allo-HSCT with RIC is associated with an increase in nonrelapse mortality and a relatively inferior OS in patients with a significantly low preconditioning ALC. Therefore, alternative strategies for the integration of ATG should be considered in allo-HSCT, at least for patients with a substantially low preconditioning ALC.     

Melphalan-Based Reduced-Intensity Conditioning is Associated with Favorable Disease Control and Acceptable Toxicities in Patients Older Than 70 with Hematologic Malignancies Undergoing Allogeneic Hematopoietic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (alloHCT) is offered increasingly to elderly patients with hematologic malignancies. However, outcome data in those who are 70 years or older are limited, and no standard conditioning regimen has been established for this population. In this retrospective study we evaluated the outcome of 53 consecutive patients aged 70 years and older who underwent alloHCT with melphalan-based reduced-intensity conditioning (RIC) at City of Hope. Engraftment was prompt, with median time to neutrophil engraftment of 15 days. More than 95% of patients achieved complete donor chimerism within 6 weeks from HCT, consistent with the “semiablative” nature of this regimen. With a median follow-up of 31.1 months, the 2-year overall survival (OS), progression-free survival (PFS), and nonrelapse mortality (NRM) were 68.9%, 63.8%, and 17.0%, respectively. Cumulative incidence of relapse at 1 and 2 years was 17.0% and 19.3%, respectively. One hundred–day cumulative incidence of grades II to IV acute graft-versus-host disease was 37.7% (grades III to IV, 18.9%), and 2-year cumulative incidence of chronic graft-versus-host disease was 61.9% (extensive, 45.9%). The only significant predictor for poor OS was high/very high disease risk index. Transplant-related complications and morbidities observed here did not differ from the commonly expected in younger patients treated with RIC. In conclusion, alloHCT with a melphalan-based conditioning regimen is associated with acceptable toxicities and NRM, lower incidence of relapse, and favorable OS and PFS in patients aged 70 years or older.