Outcomes following autologous hematopoietic stem cell transplant for patients with relapsed Wilms' tumor: a CIBMTR retrospective analysis.

Despite the marked improvement in the overall survival (OS) for patients diagnosed with Wilms' tumor (WT), the outcomes for those who experience relapse have remained disappointing. We describe the outcomes of 253 patients with relapsed WT who received high-dose chemotherapy (HDT) followed by autologous hematopoietic stem cell transplant (HCT) between 1990 and 2013, and were reported to the Center for International Blood and Marrow Transplantation Research. The 5-year estimates for event-free survival (EFS) and OS were 36% (95% confidence interval (CI); 29-43%) and 45% (95 CI; 38-51%), respectively. Relapse of primary disease was the cause of death in 81% of the population. EFS, OS, relapse and transplant-related mortality showed no significant differences when broken down by disease status at transplant, time from diagnosis to transplant, year of transplant or conditioning regimen. Our data suggest that HDT followed by autologous HCT for relapsed WT is well tolerated and outcomes are similar to those reported in the literature. As attempts to conduct a randomized trial comparing maintenance chemotherapy with consolidation versus HDT followed by stem cell transplant have failed, one should balance the potential benefits with the yet unknown long-term risks. As disease recurrence continues to be the most common cause of death, future research should focus on the development of consolidation therapies for those patients achieving complete response to therapy.

Dose-adapted post-transplant cyclophosphamide for HLA-haploidentical transplantation in Fanconi anemia.

We developed a haploidentical transplantation protocol with post-transplant cyclophosphamide (CY) for in vivo T-cell depletion (TCD) using a novel adapted-dosing schedule (25 mg/kg on days +3 and +4) for Fanconi anemia (FA). With median follow-up of 3 years (range, 37 days to 6.2 years), all six patients engrafted. Two patients with multiple pre-transplant comorbidities died, one from sepsis and one from sepsis with associated chronic GVHD. Four patients without preexisting comorbidities and early transplant referrals are alive with 100% donor chimerism and excellent performance status. We conclude that adjusted-dosing post-transplant CY is effective in in vivo TCD to promote full donor engraftment in patients with FA.

Marrow grafts from HLA-identical siblings for severe aplastic anemia: does limiting the number of transplanted marrow cells reduce the risk of chronic GvHD?

A total of 21 patients with severe aplastic anemia (SAA) underwent marrow transplantation from HLA-identical siblings following a standard conditioning regimen with cyclophosphamide (50 mg/kg/day × 4 days) and horse antithymocyte globulin (30 mg/kg/day × 3 days). Post-grafting immunosuppression consisted of a short course of methotrexate (MTX) combined with cyclosporine (CSP). The transplant protocol tested the hypothesis that the incidence of chronic GvHD could be reduced by limiting the marrow grafts to ⩽2.5 × 108 nucleated marrow cells/kg. None of the patients rejected the graft, all had sustained engraftment and all are surviving at a median of 4 (range 1-8) years after transplantation. Chronic GvHD developed in 16% of patients given ⩽2.5 × 108 nucleated marrow cells/kg. Post-grafting immunosuppression has been discontinued in 20 of the 21 patients. In conclusion, limiting the number of transplanted marrow cells may have resulted in minimal improvement in the incidence and severity of chronic GvHD.

Cyclophosphamide-based in vivo T-cell depletion for HLA-haploidentical transplantation in Fanconi anemia.

Allogeneic hematopoietic cell transplantation (HCT) is the only known cure for patients with Fanconi anemia (FA) who develop aplasia or leukemia. However, transplant regimens typically contain high-dose alkylators, which are poorly tolerated in FA patients. Furthermore, as many patients lack human leukocyte antigen (HLA)-matched family donors, alternative donors are used, which can increase the risk of both graft rejection and graft-versus-host disease (GVHD). To improve on these three concerns, we developed a multi-institutional clinical trial using a fludarabine (FLU)-based conditioning regimen with limited alkylators/low-dose radiation, HLA-haploidentical marrow, followed by reduced-dose cyclophosphamide (CY) to treat three FA patients with aplasia. All three patients engrafted with 100% donor CD3 chimerism at 1 month. One patient died early from disseminated toxoplasmosis infection. Of the two survivors, one had significant pretransplant co-morbidities and inadequate immunosuppression, and developed severe acute GVHD. The other patient had only mild acute and no chronic GVHD. With a follow-up of 2 and 3 years, respectively, both patients are doing well, are transfusion-independent, and maintain full donor chimerism. The patient with severe GVHD has resolving oral GVHD and good quality of life. We conclude that using low-intensity conditioning, HLA-haploidentical marrow, and reduced-dose CY for in vivo T-cell depletion can correct life-threatening aplasia in FA patients.

Prognostic factors for outcomes in allogeneic transplantation for CML in the imatinib era: a CIBMTR analysis.

Allogeneic hematopoietic SCT is an effective treatment in accelerated (AP) or blast phase (BP) CML. Imatinib (IM) has transient but significant activity in advanced phases of CML, which may permit early allografting for responding patients. To identify prognostic factors in allograft recipients previously treated with IM, we analyzed 449 allogeneic hematopoietic SCTs performed from 1999 to 2004 in advanced-phase CML, using the data reported to the Center for International Blood and Marrow Transplant Research. CML patients in second chronic phase (CP2, n=184), AP (n=185) and BP (n=80) received HLA-identical sibling (27%), related (3%), or matched or mismatched unrelated donor (70%), peripheral blood (47%) or BM (53%) hematopoietic SCT after myeloablative (78%) or non-myeloablative (22%) conditioning. In all, 52% in CP2, 49% in AP and 46% in BP received IM before hematopoietic SCT. Disease-free survival was 35-40% for CP2, 26-27% for AP and 8-11% for BP. Cumulative incidence of acute and chronic GVHD and TRM were not affected by the stages of CML or pre-hematopoietic SCT IM exposure. Multivariate analyses showed that conventional prognostic indicators remain the strongest determinants of transplant outcomes. In conclusion, there are no new prognostic indicators of the outcomes of allogeneic hematopoietic SCT for advanced-phase CML in the IM era.

Analysis of risk factors influencing outcome in children with myelodysplastic syndrome after unrelated cord blood transplantation.

We describe 70 children with myelodysplastic syndrome (MDS) (refractory cytopenia (n=31) and refractory anemia with excess blasts (n=30) or blasts in transformation (n=9)) who received umbilical cord blood (UCB) transplantation with a single UCB unit and a myeloablative conditioning regimen. Approximately 20% of children had secondary MDS. Median age at transplantation was 7 years and the median follow-up was 3 years. The day-60 probability of neutrophil recovery was 76%; recovery was faster after transplantation of matched or 1-locus mismatched UCB, irradiation-containing conditioning regimen, cell dose >6 × 10(7)/kg and monosomy 7. Risks of treatment failure (recurrent disease or death) were lower in patients with monosomy 7 and transplantations after 2001. The 3-year disease-free survival (DFS) was 50% for transplantations after 2001 compared with 27% for the earlier period (P=0.018). Transplantations after 2001 occurred within 6 months after diagnosis and used UCB units with higher cell dose. DFS was highest in patients with monosomy 7 (61%) compared with other karyotypes (30%), P=0.017. These data suggest that transplantation of mismatched UCB graft is an acceptable alternative for children without a matched sibling or suitably matched unrelated adult donor.

Treatment of Fanconi anemia patients using fludarabine and low-dose TBI, followed by unrelated donor hematopoietic cell transplantation.

A nonmyeloablative conditioning regimen consisting of fludarabine (FLU) and 2 Gy TBI has been used extensively and with substantial engraftment success without promoting excessive nonrelapse mortality in medically infirm patients requiring hematopoietic cell transplantation. In this paper, we studied this same low-toxicity regimen as a means of promoting engraftment of unrelated donor hematopoietic cell transplantation in patients with Fanconi anemia (FA). All patients tolerated the regimen well with no mucositis or other severe toxicities. Of six patients transplanted, five achieved stable mixed or full donor chimerism. Acute and chronic GVHD occurred in four and three patients, respectively. Three patients are alive and well at a median of 45.9 (range, 20.9-68.1) months after transplant. In summary, this FLU-based regimen facilitates stable engraftment of unrelated PBSCs, but is associated with significant chronic GVHD.

Comparison of matched unrelated and matched related donor myeloablative hematopoietic cell transplantation for adults with acute myeloid leukemia in first remission.

Hematopoietic cell transplantation (HCT) from a matched related donor (MRD) benefits many adults with acute myeloid leukemia (AML) in first complete remission (CR1). The majority of patients does not have such a donor and will require an alternative donor if HCT is to be undertaken. We retrospectively analyzed 226 adult AML CR1 patients undergoing myeloablative unrelated donor (URD) (10/10 match, n=62; 9/10, n=29) or MRD (n=135) HCT from 1996 to 2007. The 5-year estimates of overall survival, relapse and nonrelapse mortality (NRM) were 57.9, 29.7 and 16.0%, respectively. Failure for each of these outcomes was slightly higher for 10/10 URD than MRD HCT, although statistical significance was not reached for any end point. The adjusted hazard ratios (HRs) were 1.43 (0.89-2.30, P=0.14) for overall mortality, 1.17 (0.66-2.08, P=0.60) for relapse and 1.79 (0.86-3.74, P=0.12) for NRM, respectively, and the adjusted odds ratio for grades 2-4 acute graft-versus-host disease was 1.50 (0.70-3.24, P=0.30). Overall mortality among 9/10 and 10/10 URD recipients was similar (adjusted HR 1.16 (0.52-2.61), P=0.71). These data indicate that URD HCT can provide long-term survival for CR1 AML; outcomes for 10/10 URD HCT, and possibly 9/10 URD HCT, suggest that this modality should be considered in the absence of a suitable MRD.

Intensive postgrafting immune suppression combined with nonmyeloablative conditioning for transplantation of HLA-identical hematopoietic cell grafts: results of a pilot study for treatment of primary immunodeficiency disorders.

This study was designed to determine the safety of a nonmyeloablative regimen in patients with primary immunodeficiency disorders (PID) who had infections, organ dysfunction or other risk factors that precluded conventional hematopoietic cell (HC) transplant. Fourteen patients received HLA-matched related (n=6) or unrelated (n=8) HC grafts from marrow (n=8), peripheral blood mononuclear cells (n=5) or umbilical cord blood (n=1), either without conditioning (n=1), or after 200 cGy total body irradiation alone (n=3) or with 90 mg/m2 fludarabine (n=10). All patients were given postgrafting immunosuppression with mycophenolate mofetil and cyclosporine. Mixed (n=5) or full (n=8) donor chimerism was established in 13 patients, and one patient rejected the graft. Eight patients developed acute grade III (n=1) and/or extensive chronic GVHD (n=8). With a median follow-up of 4.9 (range, 0.7-8.1) years, the 3-year overall survival, event-free survival and transplant-related mortality were 62, 62 and 23%, respectively. Correction of immune dysfunction was documented in 8 of 10 patients with stable donor engraftment. These preliminary results indicated that this approach was associated with stable donor engraftment and a low incidence of early mortality and, thus, can be considered for certain high-risk patients with PID. However, there was a risk of GVHD, which is an undesirable outcome for this group of patients.

Macrophage activation syndrome and other systemic inflammatory conditions after BMT.

Autologous hematopoietic cell transplantation (HCT) is being used to treat autoimmune diseases refractory to conventional therapy, including rheumatoid arthritis. Macrophage activation syndrome (MAS) is a descriptive term for a systemic inflammatory disorder that has been described in patients with juvenile rheumatoid arthritis (JRA). This case report describes a young adult with systemic JRA (sJRA) who developed MAS on day # 12 post-autologous transplantation. The patient developed high fever, laboratory evidence of disseminated intravascular coagulation (DIC), hepatocellular injury, pancytopenia and hyper-ferritinemia. All viral, bacterial and fungal studies were negative and the patient improved with high-dose glucocorticosteroid and cyclosporine therapy. Extreme elevation of serum ferritin was documented and helpful in monitoring response to therapy. A number of systemic inflammatory syndromes have been described in association with HCT. These include DIC, 'engraftment syndrome,' infection-associated hemophagocytic syndrome and familial hemophagocytic lymphohistiocytosis. Macrophage activation syndrome presents with features of DIC and is closely related or identical to infection-associated hemophagocytic syndrome. The diagnosis needs to be established in a timely fashion because early and appropriate treatment may improve outcome.

Outcome of allogeneic bone marrow transplantation for children with advanced acute myeloid leukemia.

Allogeneic bone marrow transplantation (BMT) may offer the only chance of cure for children with acute myeloid leukemia (AML) in second complete remission (CR2) or with relapsed disease, but the outcome of these patients has not been clearly defined. We conducted a retrospective study of 58 children, median age 7.4 years (range 0.8-17.3), who received matched related or unrelated BMT at our institution for AML in CR2 (n = 12), in untreated first relapse (n = 11) or with refractory disease (n = 35), to identify risk factors associated with disease-free survival (DFS). Life threatening to fatal regimen-related toxicity was observed in 22% of patients. Estimates of DFS at 5 years (95% confidence interval) for patients in CR2, with untreated first relapse and refractory disease were 58% (27-80%), 36% (11-63%) and 9% (2-21%), respectively. Non-relapse mortality estimates were 0%, 27% (0-54%) and 17% (5-30%), and relapse estimates were 42% (14-70%), 36% (8-65%) and 74% (60-89%), respectively. Advanced disease phase and cytogenetic abnormalities at the time of transplantation were each associated with decreased DFS and increased relapse in multivariable regression models. Survival for children transplanted in CR2 or untreated first relapse is higher than that previously reported, but relapse remains the major cause of treatment failure regardless of disease stage.

Allogeneic bone marrow transplantation in children with myelodysplastic syndrome or juvenile myelomonocytic leukemia: the Seattle experience.

The purpose of this study was to evaluate the role of allogeneic bone marrow transplantation (BMT) in children with myelodysplastic syndrome (MDS). In total, 94 consecutive pediatric patients with MDS received an allogeneic BMT from 1976 to 2001 for refractory anemia (RA) (n=25), RA with ringed sideroblasts (RARS) (n=2), RA with excess blasts (RAEB) (n=20), RAEB in transformation (RAEB-T) (n=14), juvenile myelomonocytic leukemia (JMML) (n=32) or chronic myelomonocytic leukemia (CMML) (n=1). The estimated 3-year probabilities of survival, event-free survival (EFS), nonrelapse mortality and relapse were 50, 41, 28 and 29%, respectively. Patients with RA/RARS had an estimated 3-year survival of 74% compared to 68% in those with RAEB and 33% in patients with JMML/CMML. In multivariable analysis, patients with RAEB-T or JMML were 3.9 and 3.7 times more likely to die compared to those with RA/RARS and RAEB (P=0.005 and 0.004, respectively). Patients with RAEB-T were 5.5 times more likely to relapse (P=0.01). The median follow-up among the 43 surviving patients is 10 years (range 1-25). We conclude that allogeneic BMT for children with MDS is well tolerated and can be curative.

Nonmyeloablative hematopoietic cell transplant for treatment of immune deficiency.

Hematopoietic stem cell transplantation (HCT) may offer the only curative therapy for certain life-threatening immune deficiency disorders. Conventional HCT poses a risk to patients for severe morbidity, mortality, and late sequelae resulting from myeloablative preparative regimens. This review summarizes the development of nonmyeloablative regimens that have the potential to reduce both short-and long-term risks of HCT. Results of NM-HCT in a small number of patients indicate that this procedure may play an important role in treating life-threatening immune deficiencies.

Major-histocompatibility-complex class I alleles and antigens in hematopoietic-cell transplantation.

BACKGROUND: Successful engraftment of hematopoietic stem cells from unrelated donors is influenced by disparities between the donor and recipient for HLA-A, B, and C alleles. Disparities between HLA sequence polymorphisms that are serologically detectable are termed antigen mismatches, whereas those that can be identified only by DNA-based typing methods are termed allele mismatches. Whether both kinds of polymorphisms are important in transplantation is not known. We tested the hypothesis that allele mismatches that are detectable only at the DNA level are less immunogenic than those that are serologically detectable and thereby are associated with a lower risk of graft failure after hematopoietic-cell transplantation METHODS: We used DNA sequencing to define the HLA-A, B, and C alleles in 471 patients who received bone marrow from unrelated donors for the treatment of chronic myeloid leukemia after myeloablative conditioning therapy. The odds ratios for graft failure were determined for recipients of transplants from donors with a single class I allele mismatch, a single class I antigen mismatch, or two or more class I mismatches, as compared with those with no mismatch RESULTS: A single HLA allele mismatch did not increase the risk of graft failure, whereas a single antigen mismatch significantly increased the risk. The risk was also increased if the recipient was HLA homozygous at the mismatched class I locus or if the donor had two or more class I mismatches CONCLUSIONS: HLA class I antigen mismatches that are serologically detectable confer an enhanced risk of graft failure after hematopoietic-cell transplantation. Transplants from donors with a single class I allele mismatch that is not serologically detectable may be used without an increased risk of graft failure.

Trends in transplantation of hematopoietic stem cells from unrelated donors.

Transplants of hematopoietic stem cells from unrelated donors have become feasible for patients with a growing variety of hematologic disorders. The probability of finding a suitable donor has increased because of the expansion of the network of registries containing more than seven million HLA-typed donors worldwide. The selection of compatible donors has become more effective, thanks to the discovery of new HLA alleles and the development of precise and efficient HLA typing methods using DNA technology. Improved methods for transplantation may provide the opportunity to further decrease treatment-related toxicity and improve survival.

Absence of major histocompatibility class II expression does not impair hematopoiesis in mice.

OBJECTIVE: Major histocompatibility class II (MHC II) molecules are among the earliest antigens to be expressed in hematopoietic progenitor cells; however, the functional role of these molecules in hematopoiesis remains controversial. We examined the role of MHC II antigens during hematopoiesis using a mouse model of MHC II deficiency related to the absence of the critical transcriptional activator, CIITA. METHODS: Sca-1(-), Sca-1(+)lin(+), and Sca-1(+)lin(-) populations of marrow cells from CIITA(-)(/-) and wild-type mice were analyzed by immunofluorescence for MHC II expression. Hematopoietic capacity was assessed in CIITA(-/-) and wild-type mice by CFU-S, CFU-GM, and radiation sensitivity assays. RESULTS: Flow cytometric characteristics of hematopoietic progenitors from CIITA(-/-) and wild-type mice were identical except for the absence of MHC II expression in CIITA null mice. There were no significant differences in capacity for hematopoietic reconstitution and clonogenicity as measured by radiation sensitivity, CFU-S, and CFU-GM assays among CIITA(-/-) and wild-type mice. CONCLUSIONS: These experiments show that downregulation of MHC II gene transcription does not effectively alter normal hematopoiesis, and provide strong evidence that MHC II expression on hematopoietic progenitors is not required for normal hematopoietic development.

Genomics of unrelated-donor hematopoietic cell transplantation.

Unrelated-donor hematopoietic cell transplantation is a proven curative modality for hematologic malignancies. The success of unrelated-donor transplantation has been achieved through a better understanding of the immunobiology of the HLA system and through more precise and comprehensive matching of donors and recipients. The extensive polymorphism of HLA genes confers important biological implications affecting engraftment, graft-versus-host disease and overall survival. Although more-complete HLA identity of the donor and recipient is associated with optimal transplant outcome, new information suggests that not every HLA disparity is functionally relevant. Future advances in unrelated-donor transplantation must include the identification of tolerable HLA mismatches, so that more patients may benefit from this therapeutic modality. Furthermore, the role of cytokine-gene polymorphisms and minor histocompatibility genes in transplant outcome requires investigation. Delineation of the function of these markers as transplantation determinants may provide alternative means for optimizing the results of hematopoietic cell transplantation.

Non-myeloablative hematopoietic stem cell transplantation.

Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy in attempts to eradicate underlying diseases and achieve allogeneic engraftment. Preclinical studies and clinical observations have shown that to achieve engraftment conditioning regimens could be markedly reduced in intensity with reduction in treatment toxicities. The use of potent pre- and postgrafting immunosuppression facilitated stable mixed hematopoietic chimerism in a preclinical canine model. The initial clinical experiences with attenuated conditioning regimens have shown promise as a modality to achieve human stem cell transplantation with an improved safety profile. This may allow offering potentially curative hematopoietic stem cell transplantation (HSCT) to a more representative patient population (older and sicker) who are currently not eligible for such therapy. Obtaining a state of mixed hematopoietic chimerism could prove curative of the disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. On the other hand, patients with hematopoietic malignancy will likely require conversion to full donor hematopoeisis by virtue of graft-versus-host (GVH) reactions directed against both recipient hematopoiesis and underlying malignancy. The infusion of additional donor lymphocytes has been proposed by many groups to augment graft versus tumor responses, but most likely more specific strategies will need to be developed to improve efficacy and avoid nonspecific GVH reactions.

Nonmyeloablative hematopoietic stem cell transplantation: transplantation for the 21st century.

Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy to achieve allogeneic engraftment and control of underlying disease. For engraftment purposes, preclinical studies and clinical observations have shown that conditioning regimens can be markedly reduced in intensity, resulting in reduced treatment toxicities. Preclinical canine studies demonstrated that the use of potent pre- and postgrafting immunosuppression allows for reduction in conditioning regimens while facilitating development of stable mixed chimerism. If attenuated conditioning regimens can be successfully translated to human stem cell transplantation, an improved safety profile will allow potentially curative treatment to a more representative patient profile not currently offered such therapy. Mixed chimerism could prove curative of disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. For patients with hematopoietic malignancy, spontaneous conversion to full donor hematopoeisis after stem cell transplant may prove curative by virtue of graft versus host reactions directed against the malignancy, however infusion of additional donor lymphocytes may be needed to treat persistent disease.

Nonmyeloablative hematopoietic cell transplantation. Replacing high-dose cytotoxic therapy by the graft-versus-tumor effect.

Conventional allografting produces considerable regimen-related toxicities that generally limit this treatment to patients younger than 55 years and in otherwise good medical condition. T cell-mediated graft-versus-tumor (GVT) effects are known to play an important role in the elimination of malignant disease after allotransplants. A minimally myelosuppressive regimen that relies on immunosuppression for allogeneic engraftment was developed to reduce toxicities while optimizing GVT effects. Pre-transplant total-body irradiation (200 cGy) followed by post-transplant immunosuppression with cyclosporine (CSP) and mycophenolate mofetil (MMF) permitted human leukocyte antigen (HLA)-matched sibling donor hematopoietic cell engraftment in 82% of patients (n = 55) without prior high-dose therapy. The addition of fludarabine (90 mg/m2) facilitated engraftment in all 28 subsequent patients. Overall, fatal progression of underlying disease occurred in 20% of patients after transplant. Non-relapse mortality occurred in 11% of patients. Toxicities were low. Grade 2-4 acute graft-versus-host disease (GVHD) associated with primary engraftment developed in 47% of patients, and was readily controlled in all but two patients. Donor lymphocyte infusions (DLI) were not very effective at converting a low degree of mixed donor/host chimerism to full donor chimerism; however, the addition of fludarabine reduced the need for DLI. With a median follow-up of 244 days, 68% of patients were alive, with 42% of patients in complete remission, including molecular remissions. Remissions occurred gradually over periods of weeks to a year. If long-term efficacy is demonstrated, such a strategy would expand treatment options for patients who would otherwise be excluded from conventional allografting.