Graft-versus-Host Disease–Free,Relapse-Free Survival after Allogeneic Stem Cell Transplantation for Myelodysplastic Syndrome

Graft-versus-host disease–free, relapse-free survival (GRFS) is a composite endpoint that measures survival free of relapse or significant morbidity after allogeneic hematopoietic stem cell transplantation (HSCT). Consecutive adult patients (N?=?324) who received HSCT with fludarabine and busulfan–based conditioning for myelodysplastic syndrome (MDS) or secondary acute myeloid leukemia evolved from MDS were retrospectively analyzed. One-year and 3-year GRFS rates were 47.8% and 34.5%, respectively. Three fixed factors (circulating blast > 3%, high cytogenetic risk, and high comorbidity index) and 2 factors (which are) modifiable by clinicians (myeloablative conditioning [MAC] and low-dose [<7.5 mg/kg] antithymocyte globulin [ATG]) were independent factors for poor GRFS. Based on these 5 factors, 3 groups (3-year GRFS: 64.9% in low risk, 33.6% in intermediate risk, and 6.6% in high risk; P < .001) were identified. Fixed factor–adjusted GRFS in patients receiving reduced-intensity conditioning (RIC) plus high-dose ATG (≥7.5 mg/kg) was superior (P < .001) to those receiving MAC and/or low-dose ATG. Favorable influences of RIC plus ATG ≥ 7.5 mg/kg were evident in the low-risk group defined by fixed factors (3-year GRFS, 38.9% versus 4.4%; P < .001) but were not evident in the high-risk group (3-year GRFS, .0% versus 5.3%; P?=?.678). Conclusively, this study suggests that risk-adapted selection of conditioning intensity and ATG could improve qualified HSCT outcomes.     

Impact of Single-Dose Plerixafor as an Adjunct to Granulocyte Colony-Stimulating Factor–Based Peripheral Blood Stem Cell Mobilization on the Graft Composition and Outcome for T Cell–Replete Haploidentical Peripheral Blood Stem Cell Transplantation with Post-Transplantation Cyclophosphamide: A Comparative Study

We conducted a prospective study on T and natural killer (NK) cell subset composition of graft and transplant outcomes in T cell–replete haploidentical transplantation with a single dose of subcutaneous plerixafor (Px) added to granulocyte colony-stimulating factor (G-CSF)-based mobilization in allogeneic donors to collect 10?×?10⁶/kg CD34⁺ hematopoietic stem cells (HSCs) at single apheresis. Twnety-six donors received G-CSF?+?Px and 25 G-CSF alone for mobilization. Despite significantly lower peripheral blood (PB) CD34⁺ HSCs on day 4 in the G-CSF?+?Px group (33 [range, 6-47] cells/µL versus 81 [range, 50-168] cells/µL in the G-CSF group; P?=?.0001), PB CD34⁺ HSC count (median 136 versus 139 cells/µL) on day 5 as well as that in the graft (2.7 versus 2.3?×?10⁶/mL, P?=?.1) were comparable between the 2 groups. The total nucleated cell count was higher (3.4 versus 3.1?×?10⁸/mL, P?=?.05), but CD4⁺ T cells (2.3 versus 2.7?×?10⁷/mL, P?=?.09) were lower in the G-CSF group with mobilization of regulatory T cells being similar. NK cells were skewed toward the CD56⁺/16^? subset in both groups, varying significantly from the steady-state NK subset ratio in PB. The time to engraftment, incidences of acute and chronic graft-versus-host disease, nonrelapse mortality, and overall survival were also similar. Addition of single-dose Px to G-CSF mobilization improves CD34 recovery and does not significantly alter the T and NK cell composition of the graft, including regulatory T cells, with no adverse impact on transplant outcomes.     

Peripheral Blood Stem Cells versus Bone Marrow for T Cell–Replete Haploidentical Transplantation with Post-Transplant Cyclophosphamide in Hodgkin Lymphoma

Haploidentical stem cell transplantation (haplo-SCT) with post-transplant cyclophosphamide (PT-Cy) represents a potential curative strategy for patients with Hodgkin lymphoma (HL) when a matched related or unrelated donor is not available. The role of graft source, either bone marrow (BM) or peripheral blood stem cells (PBSCs), in this setting has not been fully elucidated. We performed a retrospective study on 91 patients with HL to compare the outcome after BM (n = 53) or PBSC (n = 38) transplant. Eighty-nine patients engrafted with no difference between BM and PBSCs in terms of median time for neutrophil (20 versus 20 days, P = .405) and platelet (26 versus 26.5 days, P = .994) engraftment. With a median follow-up of 40.2 months, 100-day cumulative incidences of grades II to IV acute graft-versus host disease (GVHD) and grades II to IV acute GVHD were 24% and 4%, respectively. Graft source was not associated with a different risk of acute GVHD both by univariate and multivariate analyses. Consistently, 1-year cumulative incidence of chronic GVHD was 7% with no differences between the 2 graft types (P = .761). Two-year rates of overall survival (OS), progression-free survival (PFS), nonrelapse mortality, and GVHD/relapse-free survival (GRFS) were 67%, 58%, 20%, and 52%, respectively. By univariate analysis, pretransplant disease status was the main variable affecting all outcomes. By multivariate analysis, PBSCs resulted in a protective factor for OS (hazard ratio [HR], .29; P = .006), PFS (HR, .38; P = .001), and GRFS (HR, .44; P = .020). The other independent variables affecting the final outcome were pretransplant disease status and hematopoietic cell transplant–specific comorbidity index. In conclusion, when planning a haplo-SCT with PT-Cy for patients with poor-risk HL, graft type is an important variable to take into account when selecting the best available donor.     

Comparative Analysis of Calcineurin Inhibitor–Based Methotrexate and Mycophenolate Mofetil–Containing Regimens for Prevention of Graft-versus-Host Disease after Reduced-Intensity Conditioning Allogeneic Transplantation

The combination of a calcineurin inhibitor (CNI) such as tacrolimus (TAC) or cyclosporine (CYSP) with methotrexate (MTX) or with mycophenolate mofetil (MMF) has been commonly used for graft-versus-host disease (GVHD) prophylaxis after reduced-intensity conditioning (RIC) allogeneic hematopoietic cell transplantation (alloHCT), but there are limited data comparing efficacy of the 2 regimens. We evaluated 1564 adult patients who underwent RIC alloHCT for acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL), chronic myelogenous leukemia (CML), and myelodysplastic syndrome (MDS) from 2000 to 2013 using HLA-identical sibling (matched related donor [MRD]) or unrelated donor (URD) peripheral blood graft and received CYSP or TAC with MTX or MMF for GVHD prophylaxis. Primary outcomes of the study were acute and chronic GVHD and overall survival (OS). The study divided the patient population into 4 cohorts based on regimen: MMF-TAC, MMF-CYSP, MTX-TAC, and MTX-CYSP. In the URD group, MMF-CYSP was associated with increased risk of grade II to IV acute GVHD (relative risk [RR], 1.78; P < .001) and grade III to IV acute GVHD (RR, 1.93; P = .006) compared with MTX-TAC. In the URD group, use of MMF-TAC (versus MTX-TAC) lead to higher nonrelapse mortality. (hazard ratio, 1.48; P = .008). In either group, no there was no difference in chronic GVHD, disease-free survival, and OS among the GVHD prophylaxis regimens. For RIC alloHCT using MRD, there are no differences in outcomes based on GVHD prophylaxis. However, with URD RIC alloHCT, MMF-CYSP was inferior to MTX-based regimens for acute GVHD prevention, but all the regimens were equivalent in terms of chronic GVHD and OS. Prospective studies, targeting URD recipients are needed to confirm these results.     

Graft Monocytic Myeloid-Derived Suppressor Cell Content Predicts the Risk of Acute Graft-versus-Host Disease after Allogeneic Transplantation of Granulocyte Colony-Stimulating Factor–Mobilized Peripheral Blood Stem Cells

Myeloid-derived suppressor cells (MDSCs) are powerful immunomodulatory cells that in mice play a role in infectious and inflammatory disorders, including acute graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation. Their relevance in clinical acute GVHD is poorly known. We analyzed whether granulocyte colony-stimulating factor (G-CSF) administration, used to mobilize hematopoietic stem cells, affected the frequency of MDSCs in the peripheral blood stem cell grafts of 60 unrelated donors. In addition, we evaluated whether the MDSC content in the peripheral blood stem cell grafts affected the occurrence of acute GVHD in patients undergoing unrelated donor allogeneic stem cell transplantation. Systemic treatment with G-CSF induces an expansion of myeloid cells displaying the phenotype of monocytic MDSCs (Lin^low/negHLA-DR⁻CD11b⁺CD33⁺CD14⁺) with the ability to suppress alloreactive T cells in vitro, therefore meeting the definition of MDSCs. Monocytic MDSC dose was the only graft parameter to predict acute GVHD. The cumulative incidence of acute GVHD at 180 days after transplantation for recipients receiving monocytic MDSC doses below and above the median was 63% and 22%, respectively (P = .02). The number of monocytic MDSCs infused did not impact the relapse rate or the transplant-related mortality rate (P > .05). Although further prospective studies involving larger sample size are needed to validate the exact monocytic MDSC graft dose that protects from acute GVHD, our results strongly suggest the modulation of G-CSF might be used to affect monocytic MDSCs graft cell doses for prevention of acute GVHD.     

T Cell–Depleted Related HLA-Mismatched Peripheral Blood Stem Cell Transplantation as Salvage Therapy for Graft Failure after Single Unit Unrelated Donor Umbilical Cord Blood Transplantation

Graft failure is a severe treatment complication of unrelated donor umbilical cord blood transplantation (UCBT). Its incidence seems to be higher after UCBT than after transplantation with bone marrow or peripheral blood stem cells (PBSCs). The only curative option is to perform a second transplantation; however, both the ideal stem cell source and the conditioning regimen for this salvage transplantation remain unclear. We report a series of 11 patients who underwent haploidentical PBSC transplantation (PBSCT) as salvage therapy for graft failure after a previous UCBT. The reduced-intensity conditioning regimen consisted of fludarabine 150 mg/m² for 3 days and horse antithymocyte globulin 8 mg/kg for 4 days. Ex vivo CD34⁺ positive selection was performed in all cases, and no post-transplantation graft-versus-host disease prophylaxis was used. Six of the 9 evaluable patients (67%) eventually engrafted, at a median time of 10 days. The cumulative incidence of engraftment at 28 days was 64% (95% confidence interval [CI], 35% to 92%). Two patients relapsed after PBSCT. The cumulative incidence of TRM was 55% at 2 years (95% CI, 25% to 84%), and the probability of overall survival at 2 years was 36%. Our findings suggest that haploidentical ex vivo T cell–depleted PBSCT is a feasible alternative for treating graft failure after UCBT.     

Effects of Low-Dose Glucocorticoid Prophylaxis on Chronic Graft-versus-Host Disease and Graft-versus-Host Disease–Free,Relapse-Free Survival after Haploidentical Transplantation: Long-Term Follow-Up of a Controlled,Randomized Open-Label Trial

This long-term follow-up study evaluated the effects of corticosteroid prophylaxis on graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) based on a controlled open-label randomized trial in which 228 allotransplant recipients were categorized as low risk (n?=?83, group A) or high risk; patients at high risk were randomly assigned to receive (n?=?72, group B) or not receive (n?=?73, group C) low-dose methylprednisolone prophylaxis. The cumulative incidences of chronic GVHD, relapse, nonrelapse mortality, leukemia-free survival, overall survival, and GRFS were 60%, 19%, 16%, 68%, 73%, and 46%, respectively, in all cases. Compared with the patients in group C, the cases in group B experienced a lower cumulative incidence of moderate to severe chronic GVHD (42% versus 20%; P = .010), herpes zoster infection (28% versus 12%; P = .010), pulmonary infections (42% versus 21%; P = .040), and osteonecrosis of the femoral head (ONFH; 16% versus 6%; P = .045) as well as better GRFS (59% versus 33%; P = .017). Factors associated with GRFS included total dose of corticosteroid used in the first 100days after transplantation (hazard ratio, 1.547; P?=?.015) and platelet recovery (hazard ratio, 1.456; P?=?.037). Our results suggest that low-dose glucocorticoid prophylaxis reduces GVHD and thus reduces the total dose of steroids, which might contribute to lower incidence of infections and ONFH and a superior GRFS, indicating that higher steroid doses are harmful. Reducing the total dose is of course beneficial. (ClinicalTrials.gov number, NCT01607580.)     

Single Antigen–Mismatched Unrelated Hematopoietic Stem Cell Transplantation Using High-Dose Post-Transplantation Cyclophosphamide Is a Suitable Alternative for Patients Lacking HLA-Matched Donors

The optimal prophylaxis regimen for graft-versus-host disease (GVHD) in the setting of mismatched unrelated donor (MMUD) allogeneic hematopoietic stem cell transplantation (alloHSCT) is not defined. The use of high-dose post-transplant cyclophosphamide (PTCy) in haploidentical transplantation has proven feasible and effective in overcoming the negative impact of HLA disparity on survival. We hypothesized that PTCy could also be effective in the setting of MMUD transplantation. We retrospectively analyzed 86 consecutive adult recipients of alloHSCT in our institution, comparing 2 contemporaneous groups: PTCy MMUD (n?=?26) versus matched unrelated donor (MUD) (n?=?60). Graft source was primarily peripheral blood (92%). All PTCy MMUD were HLA 7/8 (differences in HLA class I loci in 92% of patients) and received PTCy plus tacrolimus ± mofetil mycophenolate as GVHD prophylaxis. No differences were observed between PTCy MMUD and MUD in the 100-day cumulative incidence of acute GVHD grades II to IV (31% versus 22%, respectively; P?=?.59) and III to IV (8% versus 10%, P?=?.67). There was a trend for a lower incidence of moderate to severe chronic GVHD at 1 year after PTCy MMUD in comparison with MUD (22% versus 41%, P?=?.098). No differences between PTCy MMUD and MUD were found regarding nonrelapse mortality (25% versus 18%, P?=?.52) or relapse rate (11% versus 19%, P?=?.18). Progression-free survival and overall survival at 2 years were similar in both cohorts (67% versus 54% [HR, .84; 95% CI, .38 to 1.88; P?=?.68] and 72% versus 57% [HR, .71; 95% CI, .31 to 1.67; P?=?.44], respectively). The 2-year cumulative incidence of survival free of moderate to severe chronic GVHD and relapse tended to be higher in the PTCy MMUD group (47% versus 24%; HR, .60; 95% CI, .31 to 1.14; P?=?.12). We conclude that HLA 7/8 MMUD transplantation using PTCy plus tacrolimus is a suitable alternative for those patients who lack a MUD.     

Human Herpes Virus-6–Associated Encephalitis/Myelitis Mimicking Calcineurin Inhibitor–Induced Pain Syndrome in Allogeneic Stem Cell Transplantation Recipients

Human herpes virus-6 (HHV6)-associated myelitis and calcineurin inhibitor–induced pain syndrome (CIPS) are serious complications of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Because these 2 complications cause similar sensory nerve–related symptoms, such as paresthesia, pruritus, and severe pain occurring around the engraftment, it can be difficult to differentially diagnose the 2 conditions. We retrospectively analyzed 435 recipients to distinguish clinical symptoms of these 2 complications. Twenty-four patients (5.5%) developed HHV6-associated encephalitis/myelitis; of these, 11 (2.5%) presented only with myelitis-related symptoms (HHV6-associated myelitis), which was confirmed by the detection of HHV6 DNA, and 8 (1.8%) had CIPS, with undetected HHV6 DNA. All patients with HHV6-associated myelitis or CIPS exhibited similar sensory nerve–related symptoms. Diagnostic images did not provide definite evidence specific for each disease. Symptoms of all patients with CIPS improved after switching to another immunosuppressant. Overall survival rate at 2 years for patients with HHV6-associated encephalitis/myelitis was significantly lower than that of CIPS (13.1% versus 29.2%; P?=?.049) or that of patients without HHV6-associated encephalitis/myelitis or CIPS (42.4%; P?=?.036), whereas there was no significant difference among the latter 2 groups (P?=?.889). The development of HHV6-associated encephalitis/myelitis but not CIPS was significantly associated with poor prognosis. Thus, transplant physicians should be aware that sensory nerve–related symptoms indicate early manifestations that might be correlated with reactivation of HHV6 or CIPS. Therefore, identification of HHV6 DNA is crucial for making a differential diagnosis and immediately starting appropriate treatments for each complication.     

Unrelated Donor Peripheral Blood Stem Cell Transplantation for Patients with β-Thalassemia Major Based on a Novel Conditioning Regimen

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only available curative treatment for patients with β-thalassemia major (β-TM). However, the problem of finding a suitable sibling donor with well-matched human leukocyte antigens is still a major obstacle to curing these patients. With the progress in high-resolution HLA typing technology and supportive care, outcomes after allogeneic HSCT from an HLA well-matched unrelated donor (UD) now approach those of well-matched sibling donors. However, UD HSCT is hampered by an increased risk of graft-versus-host disease and transplant-related mortality. Here we report the outcome of transplantation in patients with β-TM using a novel WZ-14-TM transplant protocol, based on cyclophosphamide, intravenous busulfan, fludarabine, and antithymocyte globulin, in our center. Forty-eight patients between 2 and 11 years of age with β-TM received HLA well-matched UD peripheral blood stem cell transplantation following the WZ-14-TM protocol. All of the transplanted patients achieved donor engraftment. The incidences of grade II to IV acute and chronic graft-versus-host disease were 8.3% and 8.3%, respectively. The overall survival and thalassemia-free survival rates were both 100%. This encouraging result suggests that the WZ-14-TM protocol is a feasible and safe conditioning regime for patients with β-TM undergoing UD HSCT.     

Changing Epidemiology of Clostridium difficile–Associated Disease during Stem Cell Transplantation

The incidence and severity of Clostridium difficile–associated disease (CDAD) within the general population has risen dramatically over the past decade, yet little data are available from hematopoietic stem cell transplantation (HSCT) centers. In the present study, we performed a chart review of 822 consecutive autologous and allogeneic HCST recipients treated at Northwestern Memorial Hospital between 2004 and 2008 to determine the incidence of CDAD at our institution. Variables including age, sex, diagnosis, chemotherapy regimen, transplantation type, microbial colonization, coinfections, diet, antibiotic use, neutropenic fever, comorbid conditions, time to engraftment, growth factor administration, and occurrence of graft-versus-host disease were assessed as potential risk factors for the development of CDAD. Eighty-five CDAD cases (10.3%) were identified. Bivariate analysis revealed a significant association between CDAD and neutropenic fever, administration of a neutropenic diet, ciprofloxacin and aztreonam use and duration of therapy, vancomycin and aztreonam use and duration of therapy, receipt of an allogeneic transplantation, bacterial coinfection, and vancomycin-resistant Entereococcus faecium (VRE) colonization. Cox regression analysis identified the following as factors associated with the development of CDAD: age >60 years, allogeneic transplantation, and prior VRE colonization. Allogeneic recipients with CDAD experienced increased higher rates of grades II to IV gastrointestinal graft-versus-host disease and nonrelapse mortality. A risk stratification model was developed to identify HSCT recipients at different levels of risk. With an incidence >10%, CDAD is a significant infectious complication of stem cell transplantation.     

Lower Graft-versus-Host Disease and Relapse Risk in Post-Transplant Cyclophosphamide–Based Haploidentical versus Matched Sibling Donor Reduced-Intensity Conditioning Transplant for Hodgkin Lymphoma

Classic Hodgkin lymphoma (cHL) patients with relapsed or refractory disease may benefit from allogeneic hematopoietic cell transplantation (allo-HCT), but many lack a matched sibling donor (MSD). Herein, we compare outcomes of 2 reduced-intensity conditioning (RIC) HCT platforms in cHL: T cell–replete related donor haploidentical (haplo) HCT with a post-transplant cyclophosphamide (PTCy)-based approach versus an MSD/calcineurin inhibitor (CNI)-based approach. The study included 596 adult patients who underwent a first RIC allo-HCT for cHL between 2008 and 2016 using either a haplo-PTCy (n = 139) or MSD/CNI-based (n = 457) approach. Overall survival (OS) was the primary endpoint. Secondary endpoints included acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD), nonrelapse mortality (NRM), relapse/progression, and progression-free survival (PFS). On multivariate analysis, there was no significant difference between haplo/PTCy and MDS/CNI-based approaches in terms of OS (hazard ratio [HR], 1.07; 95% confidence interval [CI], .79 to 1.45; P = .66) or PFS (HR, .86; 95% CI, .68 to 1.10; P = .22). Haplo/PTCy was associated with a significantly higher risk of grades II to IV aGVHD (odds ratio [OR], 1.73, 95% CI, 1.16 to 2.59; P = .007), but the risk of grades III to IV aGVHD was not significantly different between the 2 cohorts (OR, .61; 95% CI, .29 to 1.27; P = .19). The haplo/PTCy platform provided a significant reduction in cGVHD risk (HR, .45; 95% CI, .32 to .64; P < .001), and a significant reduction in relapse risk (HR, .74; 95% CI, .56 to .97; P = .03). There was a statistically nonsignificant trend toward higher NRM with a haplo/PTCy approach (HR, 1.65; 95% CI, .99 to 2.77; P = .06). Haplo/PTCy-based approaches are associated with lower incidences of cGVHD and relapse, with PFS and OS outcomes comparable with MSD/CNI-based approaches. There was a leaning toward higher NRM with a haplo/PTCy-based platform. These data show that haplo/PTCy allo-HCT in cHL results in survival comparable with MSD/CNI-based allo-HCT.     

T Cell–Depleted Stem Cell Transplantation for Adults with High-Risk Acute Lymphoblastic Leukemia: Long-Term Survival for Patients in First Complete Remission with a Decreased Risk of Graft-versus-Host Disease

Consolidation with allogeneic hematopoietic stem cell transplantation (allo-HSCT) provides a survival benefit to patients with acute lymphoblastic leukemia (ALL). We have previously reported comparable survival and relapse rates after T cell–depleted (TCD) allo-HSCT compared with unmodified transplantations for acute myelogenous leukemia, myelodysplastic syndrome, and non-Hodgkin lymphoma with significantly decreased graft-versus-host disease (GVHD). We performed a 56-patient retrospective study to evaluate TCD allo-HSCT for the treatment of ALL after myeloablative total body irradiation–based therapy. The 2-year and 5-year overall survival rates for patients with ALL after TCD allo-HSCT were 0.39 (95% confidence interval [CI], 0.26-0.52) and 0.32 (95% CI, 0.19-0.44), respectively, and the 2-year and 5-year disease-free survival rates were 0.38 (95% CI, 0.25-0.50) and 0.32 (95% CI, 0.20-0.44). There was a trend toward improved survival of patients who underwent TCD allo-HSCT in first complete remission compared with those who did so in other remission states. The cumulative incidence of grade II-IV acute GVHD at 1 year was 0.20 (95% CI, 0.10-0.31), and no patients developed grade IV acute GVHD. The cumulative incidence of chronic GVHD in 41 evaluable patients at 2 and 5 years was 0.15 (95% CI, 0.04-0.26), and that of extensive chronic GVHD at 2 and 5 years was 0.05 (95% CI, 0-11.6). We demonstrate OS and DFS rates that compare favorably to unmodified allo-HSCT with lower rates of GVHD.     

Umbilical Cord Blood as an Alternative Source of Reduced-Intensity Hematopoietic Stem Cell Transplantation for Chronic Epstein-Barr Virus–Associated T or Natural Killer Cell Lymphoproliferative Diseases

Chronic Epstein-Barr virus–associated T/natural killer cell lymphoproliferative diseases represented by chronic active Epstein-Barr virus infection are lethal but are curable with several courses of chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT). Recently, we reported that reduced-intensity conditioning (RIC) provided better outcomes than myeloablative conditioning because RIC was less toxic. However, it was unclear whether cord blood transplantation (CBT) works in the context of RIC. We retrospectively analyzed 17 patients who underwent RIC followed by bone marrow transplantation (RIC-BMT) and 15 patients who underwent RIC followed by CBT (RIC-CBT). The representative regimen was fludarabine and melphalan based. The overall survival rates with RIC-BMT and RIC-CBT were 92.9% ± 6.9% and 93.3% ± 6.4%, respectively (P = .87). One patient died of lung graft-versus-host disease after RIC-BMT, and 1 patient died of multiple viral infections after RIC-CBT. Although cytotoxic chemotherapy was also immunosuppressive and might contribute to better donor cell engraftment after RIC-HSCT, the rate of engraftment failure after RIC-CBT was still higher than that after RIC-BMT (not significant); however, patients who had experienced graft failure were successfully rescued with a second HSCT. Unrelated cord blood can be an alternative source for RIC-HSCT if a patient has no family donor.     

HLA-Haploidentical T Cell–Depleted Allogeneic Hematopoietic Stem Cell Transplantation in Children with Fanconi Anemia

We report the outcome of 12 consecutive pediatric patients with Fanconi anemia (FA) who had neither an HLA-identical sibling nor an HLA-matched unrelated donor and who were given T cell–depleted, CD34⁺ positively selected cells from a haploidentical related donor after a reduced-intensity, fludarabine-based conditioning regimen. Engraftment was achieved in 9 of 12 patients (75%), and the cumulative incidence of graft rejection was 17% (95% confidence interval [CI], 5% to 59%). Cumulative incidences of grades II to IV acute and chronic graft-versus-host disease were 17% (95% CI, 5% to 59%) and 35% (95% CI, 14% to 89%), respectively. The conditioning regimen was well tolerated, with no fatal regimen-related toxicity and 3 cases of grade III regimen-related toxicity. The cumulative incidence of transplant-related mortality was 17% (95% CI, 5% to 59%). The 5-year overall survival, event-free survival, and disease-free survival were 83% (95% CI, 62% to 100%), 67% (95% CI, 40% to 93%), and 83% (95% CI, 62% to 100%), respectively. These data demonstrate that a fludarabine-based conditioning regimen, followed by infusion of high doses of T cell–depleted stem cells, is able to ensure engraftment with good overall survival and disease-free survival, confirming the feasibility of haploidentical hematopoietic stem cell transplantation in FA. To the best of our knowledge, this is the largest series of hematopoietic stem cell transplantation from a haploidentical related donor in FA patients reported to date.