Transient engraftment of syngeneic bone marrow after conditioning with high-dose cyclophosphamide and thoracoabdominal irradiation in a patient with aplastic anemia

We describe the clinical course of a 16 year old girl with aplastic anemia who was treated by syngeneic bone marrow transplantation. Engraftment was not obtained by simple infusion of bone marrow without immunosuppression. The patient received a high-dose cyclophosphamide and thoracoabdominal irradiation, followed by second marrow transplantation from the same donor. Incomplete but significant hematologic recovery was observed; however, marrow failure recurred 5 months after transplantation. Since donor and recipient pairs were genotypically identical, graft failure could not be attributed to immunological reactivity of recipient cells to donor non-HLA antigens. This case report implies that graft failure in some cases of aplastic anemia might be mediated by inhibitory cells resistant to cyclophosphamide and irradiation.     

Fludarabine,cyclophosphamide, anti‐thymocyteglobulin,and low‐dose total body irradiation conditioning enables 1‐HLA‐locus‐mismatched hematopoietic stem cell transplantation for very severe aplastic anemia without affecting ovarian function

Allogeneic hematopoietic stem cell transplantation for severe aplastic anemia from an alternative donor is associated with higher risks of graft rejection and severe graft‐versus‐host disease. We developed a conditioning regimen consisting of rabbit anti‐thymocyte globulin, fludarabine, cyclophosphamide, and low‐dose total body irradiation. Two adult female patients with transfusion‐dependent very severe aplastic anemia underwent 1‐locus mismatched transplantation using this regimen. Both patients achieved stable engraftment and the clinical course thereafter was uneventful with persistently normal ovarian function. This novel conditioning regimen may be suitable for alternative donor transplantation for severe aplastic anemia, especially in young female patients. Am. J. Hematol. 2009. © 2008 Wiley‐Liss, Inc.     

Graft failure following bone marrow transplantation for severe aplastic anemia: risk factors and treatment results

Graft failure was analyzed in 625 patients receiving allogeneic bone marrow transplants from HLA-identical sibling donors as treatment for severe aplastic anemia. Sixty-eight (11%) had no or only transient engraftment. Second bone marrow transplants were successful in achieving extended survival in 16 of 27 patients with transient initial engraftment but in none of ten patients with no sign of engraftment after the first transplant. The major factors associated with a reduced risk of graft failure were use of radiation for pretransplant immunosuppression and use of cyclosporine rather than methotrexate or T- cell depletion of the donor bone marrow for prophylaxis against graft-v- host disease (GVHD). Among 266 patients prepared for transplantation with cyclophosphamide alone, the risk of graft failure was increased in patients who received previous transfusions and reduced in those who received corticosteroids for previous therapy. Neither cell dose nor administration of donor buffy coat cells affected the probability of engraftment. Although use of radiation in conditioning reduced graft failure, survival was not improved. Posttransplant treatment with cyclosporine and avoidance of pretransplant blood transfusions were associated with improved survival.     

Allogeneic Peripheral Blood Stem Cell Transplantation for Severe Aplastic Anemia

Abstract: Allogeneic peripheral blood stem cell transplantation (PBSCT) is rarely applied for the treatment of severe aplastic anemia (SAA) because of questionable durability of engraftment and increased risk of graft versus host disease (GVHD). We performed allogeneic PBSCT in 3 SAA patients from their human leukocyte antigen (HLA)–identical siblings. One received bone marrow after conditioning with cyclophoshamide (Cy) plus antithymocyte globulin. He had a second transplant with peripheral blood stem cells from the original donor because of a graft failure (GF). Two other patients received PBSCT as a first option, with Cy as the only conditioning drug. The 3 patients received short‐term methotrexate and cyclosporine as a postgrafting immunosupression. In the latter 2 cases, no GF has been observed, and a successful and complete hematological recovery was achieved and maintained for 28 and 25 months, respectively. In conclusion, PBSCT provides a quick and complete hematological recovery in SAA patients.     

Bone marrow transplants from mismatched related and unrelated donors for severe aplastic anemia

For patients with acquired severe aplastic anemia without a matched sibling donor and not responding to immunosuppressive treatment, bone marrow transplantation from a suitable alternative donor is often attempted. We examined risks of graft failure, graft-versus-host disease and overall survival after 318 alternative donor transplants between 1988 and 1998. Sixty-six patients received allografts from 1-antigen and 20 from >1-antigen mismatched related donors; 181 from matched and 51 from mismatched unrelated donors. Most patients were young, had had multiple red blood cell transfusions and poor performance score at transplantation. We did not observe differences in risks of graft failure and overall mortality by donor type. The probabilities of graft failure at 100 days after 1-antigen mismatched related donor, >1-antigen mismatched related donor, matched unrelated donor and mismatched unrelated donor transplants were 21, 25, 15 and 18%, respectively. Corresponding probabilities of overall survival at 5 years were 49, 30, 39 and 36%, respectively. Although alternative donor transplantation results in long-term survival, mortality rates are high. Poor performance score and older age adversely affect outcomes after transplantation. Therefore, early referral for transplantation should be encouraged for patients who fail immunosuppressive therapy and have a suitable alternative donor.     

Successful bone marrow transplantation in children with severe aplastic anemia using HLA-partially matched family donors

Bone marrow transplantation (BMT) using HLA-partially matched family donors has produced disappointing results (25–30% of long-term survivors) in patients with severe aplastic anemia. We describe two children affected by severe aplastic anemia, not responsive to immunosuppressive therapy, who underwent allogeneic bone marrow transplantation using a HLA-partially matched family donor. Both cases presented 2 first class HLA-antigens (A and B) disparity between donor and recipient. The pretransplant conditioning regimen consisted of cyclophosphamide, thoracoabdominal irradiation, cytosine-arabinoside, and antilymphocyte globulin. As graft versus host disease (GVHD) prophylaxis, Cyclosporine-A was administered at usual dosages for 6 months. A full marrow engraftment was observed in both cases. Only grade I acute GVHD, promptly responsive to corticosteroid therapy, developed with no chronic GVHD. Five months after transplant, both children progressively developed hypertension, renal function impairment, thrombocytopenia, and severe normochromic anemia, with erythropoietin serum levels lower than expected for the haematocrit. After antihypertension treatment and supportive therapy, the clinical picture progressively improved, while treatment with recombinant human erythropoietin completely corrected the long-lasting anemia. The two children are alive and well 28 months after the transplant, with a Karnofsky score of 100% and a normal peripheral blood count. The authors suggest that, once immunosuppressive therapy has failed, BMT from donors other than HLA-identical sibling is a feasible approach in children affected by severe aplastic anemia, not having an HLA-identical donor. © 1993 Wiley-Liss, Inc.     

Aplastic anemia: biology and treatment

Aplastic anemia is characterized by decreased bone marrow function with inadequate production of erythrocytes, granulocytes, and platelets. Marrow failure may be caused by absence of or defects in hematopoietic stem cells, abnormalities of the bone marrow microenvironment, ineffective cell-to-cell interactions, or immune disorders. Although most patients with aplastic anemia have normal immunity, some have abnormalities of T- and B-lymphocytes. Rare patients have an immune cause of marrow failure. Treatment of aplastic anemia involves blood transfusions and withdrawal of potential causal factors. Efforts to stimulate hematopoiesis with androgens, corticosteroids, and other drugs have been largely unsuccessful. Some patients may recover after treatment with antithymocyte globulin or other immunosuppressive agents. Bone marrow transplantation is the preferred treatment for patients with severe aplastic anemia who have a human-leukocyte-antigen-identical related donor. Transplants of hematopoietic stem cells obtained from alternative sources, such as fetal liver cells or stem cells from long-term, in-vitro cultures, also may be useful.     

Late graft failure 8 years after first bone marrow transplantation for severe acquired aplastic anemia

A 14-year-old patient with acquired very severe aplastic anemia (VSAA) underwent bone marrow transplantation (BMT) from his HLA-identical brother. Preparative therapy was cyclophosphamide (CY) 200 mg/kg over 4 days. GVHD prophylaxis was with cyclosporin A (CsA) for a year. After an 8 year follow-up during which the patient was well with normal blood counts, graft failure occurred. At this time marrow chimerism studies demonstrated that 85% of hemopoiesis was of recipient origin. The patient was re-engrafted from the same donor after conditioning with CY 200 mg/kg over 4 days plus rabbit antithymocyte globulin (ATG) 3.5 mg/kg/day for 3 days. After 140 days follow-up he has a normal blood count. The possible causes of the graft failure are discussed. This case demonstrates that, although rarely, very late graft failure may occur after BMT for AA and highlights the need for long-term monitoring even in apparently successfully transplanted patients.     

Effects of in vitro depletion of T cells in HLA-identical allogeneic marrow grafts

We report results of a pilot study designed to evaluate the effects of in vitro depletion of T lymphocytes from donor marrow in patients receiving HLA-identical marrow grafts for treatment of hematologic malignancies. Twenty patients aged 31 to 50 years were prepared for transplantation with cyclophosphamide (120 mg/kg) and fractionated total body irradiation (12.0 or 15.75 Gy). All received cyclosporine after grafting. The donor marrows were treated with a mixture of eight murine monoclonal antibodies and rabbit serum complement in a manner that achieved a 2- to 3-log depletion of T cells in most patients. Initial engraftment occurred promptly in 19 of the patients, and only three had clinically significant acute graft-versus-host disease. Depletion of donor T cells, however, was associated with an increased incidence of graft failure, which occurred as late as 244 days after transplantation. Graft failure was transient in one patient but apparently was irreversible in seven others. Three of the seven patients had cytogenetic but not morphological evidence of leukemic relapse at the time of graft failure. All seven patients with irreversible graft failure have died, six after receiving second bone marrow transplants. Seven of the eight cases of graft failure occurred among the 11 patients prepared for transplantation with 12.0 Gy of total-body irradiation, and only one occurred among the nine patients with advanced malignancies who received 15.75 Gy of total-body irradiation. This association with irradiation dose suggests that host factors were partly responsible for the graft failures. Because graft failure seldom occurs in irradiated recipients of unmodified HLA- identical allogeneic marrow transplants, it appears that T cells in the donor marrow may serve a beneficial function in helping to maintain sustained engraftment possibly by eliminating host cells that can cause graft failure. Optimal application of in vitro manipulation of donor marrow as a method for preventing graft-versus-host disease will require more effective immunosuppression of the recipient in order to assure sustained engraftment and function of donor stem cells.     

Bone marrow transplantation from identical twins in the treatment of aplastic anaemia: implication for the pathogenesis of the disease

S ummary . Treatment of aplastic anaemia by bone marrow transplantation from a syngeneic (identical twin) donor has provided insights into the pathophysiology of the disease.
We report from patients with severe anaemia who were treated by syngeneic bone marrow transplantation. None of the patients had sustained recovery of peripheral blood counts. All four received second transplants from the same twin donor after immunosuppressive conditioning treatment. Each had prompt recovery of haematopoiesis. A review of the literature indicates that failure of syngeneic bone marrow transplantation in patients with aplastic anaemia is not uncommon. These data indicate that aplastic anaemia may be caused by a mechanism other than an absence or intrinsic abnormality of haematopoietic stem cells in many patients.     

Haploidentical donor transplants for severe aplastic anemia

Haploidentical stem cell transplantation (HAPLO) is being increasingly used, and significant progress has been made both with ex vivo T-cell depleted grafts as well as with unmanipulated marrow or peripheral blood grafts. We here review the current status of HAPLO grafts in patients with acquired severe aplastic anemia. Several transplant platforms have been tested, to overcome graft severe rejection and graft vs host disease (GvHD): these include differences in the conditioning regimen, in graft source and graft manipulation, and in GvHD prophylaxis. The latter include ex vivo T-cell depletion and/or antithymocyte globulin and/or high dose post-transplant cyclophosphamide. Some programs also include the use of marrow or cord blood mesenchymal stem cells, infused at the time of transplantation. Extremely encouraging results are being reported especially in the pediatric population, but also in young adults: we will review reports on 375 patients, with an average rejection rate of 6%, grade II-IV GvHD of 23% and 1-year survival of 80%. Finally we will discuss the place of HAPLO transplants in the context of alternative donor grafts for acquired aplastic anemia.     

Successful Bone Marrow Transplantation for Severe Aplastic Anemia in a Patient with Persistent Human Parvovirus B19 Infection

Persistent infection with human parvovirus B19 (B19) is primarily associated with chronic bone marrow failure in immunocompromised patients, but occasionally this organism may also affect immunocompetent hosts. B19 is also suggested as a causative agent of organ failure during bone marrow transplantation (BMT).We herein report the case of a 9-year-old girl with no previous history of immunodeficiency who developed severe aplastic anemia concurrent with B19 persistent infection. Both immunoglobulin (Ig)M antibody to B19 and B19 DNA identified by real-time polymerase chain reaction were found in the patient's serum at time of diagnosis of aplastic anemia. No giant proerythroblasts were found in her bone marrow at diagnosis. Although intravenous administration of Ig (IVIg) reduced serum B19 DNA, the aplastic status of her bone marrow did not improve. Both aplastic anemia and persistent B19 viremia were successfully treated by BMT from an HLA-identical sibling donor. Serum B19 DNA increased temporarily after BMT; however, neither organ nor marrow failure was observed. B19 DNA disappeared from the serum 2 months after BMT, suggesting that a normal immune response was restored by BMT and terminated the B19 viremia. During BMT, use of high-titer IVIg for B19 might prevent B19-associated organ failure.     

Current status of allogeneic bone marrow transplantation in acquired aplastic anemia

Bone marrow transplantation is an effective therapy for aplastic anemia. Infusion of allogeneic hematopoietic stem cells after high-dose immune suppression restores normal hematopoiesis in most patients and long-term follow-up has confirmed the durability of donor hematopoiesis. However, success of this approach is limited by transplant-related complications, such as graft failure, graft-versus-host disease, and various organ toxicities. Long-term survival rates range from less than 40% to more than 90% in reported series. These rates have improved over the past 20 years due to significant reductions in graft-versus-host disease, interstitial pneumonitis, and early transplant-related mortality. Most long-term survivors have excellent performance status. Late effects such as cataracts, thyroid disorders, joint problems, and therapy-related cancers are observed, especially in patients who received radiation for pretransplant conditioning. Results are best in young patients transplanted with bone marrow from a human leukocyte antigen (HLA)-identical sibling; early transplantation is appropriate in this group. For older patients or those without an HLA-identical related donor, transplants are better reserved for those who fail to respond to immunosuppressive therapy.     

Marrow transplantation for paroxysmal nocturnal hemoglobinuria.

Between 1971 and 1990, nine patients ranging in age from 14-38 years received marrow transplants for paroxysmal nocturnal hemoglobinuria (PNH). Six were transplanted for aplastic complications of PNH. Four of these were from HLA-identical siblings, and the patients were conditioned with cyclophosphamide. One graft was form a syngeneic twin without conditioning, and one from a two HLA-antigen nonidentical father after conditioning with cyclophosphamide and total body irradiation. Three of the four recipients of allogeneic marrow developed acute and two chronic graft-versus-host disease (GVHD). Five of six transplanted for severe aplastic anemia are long-term survivors with follow-up ranging from more than 6.2 to more than 19.1 years. The HLA nonidentical transplant recipient experienced graft rejection and died of a pulmonary hemorrhage. Three patients were transplanted for nonaplastic complications of PNH consisting of life threatening recurrent thromboses or refractory hemolysis. Two of these patients received marrow grafts from HLA-identical siblings after conditioning with busulfan and cyclophosphamide. They are surviving with normal hemograms greater than 2.2 and greater than 2.5 years and had mild chronic GVHD which resolved, although one has biochemical evidence of PNH in 15% of the red cells. One received a syngeneic marrow graft without conditioning but reverted to PNH. He is alive greater than 8.6 years after transplantation. Marrow transplantation for aplastic complications of PNH is successful, well tolerated, and compatible with long-term survival when an HLA-identical sibling or a syngeneic donor is available. For patients without aplasia, one must weigh the complications of transplantation with the life threatening nature of thrombotic episodes and hemolysis.     

配型不合造血干细胞移植治疗重型再生障碍性贫血的疗效及安全性

目的 研究人类白细胞抗原(HLA)配型不合造血干细胞移植治疗重型再生障碍性贫血(SAA)的疗效和安全性.方法 从2006年1月至2010年5月共入选17例SAA患者接受配型不合造血干细胞移植治疗,供受者间HLA 2个位点不合8例,3个位点不合9例,以改良马利兰/环磷酰胺+抗人胸腺细胞免疫球蛋白(BU/CY+ATG)为预处理方案,进行骨髓加外周血干细胞移植.结果 所有病例均达到完全供者植入.发生Ⅲ～Ⅳ度急性移植物抗宿主病(GVHD)3例,14例可评估病例中,广泛型慢性GVHD 1例;中位随访285(60～1670)d,11例患者生存,9例血象恢复正常,另2例脱离输血.6例患者死于移植相关合并症.结论 当无HLA配型相合同胞供者时,SAA患者采用HLA配型不合移植是可行的治疗选择.

Abstract：

Objective To study the efficacy and safety of human leukocyte antigen (HLA)mismatched hematopoietic stem cell transplantation (HSCT) on severe aplastic anemia(SAA). Methods From January 2006 to May 2010, 17 patients received mismatched HSCT. HLA antigens were 3-locimismatched in 9 patients, 2-loci-mismatched in 8. All patients received recombinant human granulocyte colony-stimulating factor (rhG-CSF) primed bone marrow cells plus peripheral blood stem cells after modified busulfan/cyclophosphamide + antithymocyte immunoglobulin (BU/CY + ATG ) conditioning regimen. Results All patients achieved full donor type engraftment. Grade Ⅲ-Ⅳ graft versus host disease (GVHD) occurred in 3 patients and extensive chronic GVHD in 1. With a median following-up time of 285(60-1670) d, 11 patients were alive, 9 of them had normal blood counts and the other 2 were blood transfusion independent. Six patients died of transplant-related complications. Conclusion Mismatched HSCT is a feasible and safe option for SAA patients without sibling identical donors.     

Outcomes of matched sibling and alternative donor stem cell transplantation for 26 children with severe aplastic anemia

In this study, we reported the outcomes of hematopoietic stem cell transplantation (HSCT) as a treatment modality for pediatric patients admitted over the past 20 years in a single institute. From January 1989 to January 2007, 26 patients with a median age of 8 years underwent 14 matched sibling donor (MSD) and 12 alternative donor (AD) transplantations. Two patients received second transplantation successfully after primary graft failure and late graft rejection. Two patients who received transplantation from matched unrelated donors (MUD) died of sepsis, and one of them also had a graft failure at death. The overall 5-year survival rate was 92.1%: 83.3% for AD transplantation and 100% for MSD transplantation. Grade II acute graft versus host disease (GVHD) developed in 3 patients, and extensive chronic GVHD developed in 2 patients. An interval of more than 6 months from diagnosis to transplantation was the major poor prognostic factor for our patients’ survival. Thus, in our experience, HSCT from a MSD remains the first choice of treatment for pediatric patients with severe aplastic anemia. For patients without MSD, transplantation from an AD can also result in long-term survival. Earlier transplantation after diagnosis can also result in better outcomes.     

Mixed hematologic chimerism after allogeneic marrow transplantation for severe aplastic anemia is associated with a higher risk of graft rejection and a lessened incidence of acute graft-versus-host disease

Ninety-six patients with severe aplastic anemia who received a sex- mismatched, HLA-identical allogeneic sibling marrow transplant had sequential cytogenetic analyses performed to determine the incidence and implications of posttransplant mixed hematologic chimerism. Of the 96 patients, 56 (58.3%) became mixed chimeras with coexisting host and donor cells detected in peripheral blood or marrow 14 days or later after transplant, and 40 patients (41.7%) were complete chimeras with 100% donor-type hematopoietic cells. The incidence of mixed chimerism was independent of prior blood production transfusions and infusion of donor buffy coat. The rejection rate was significantly increased in the mixed chimeric group, particularly in patients not receiving buffy coat (14 of 36 rejecting), although overall, the majority (69.7%) retained their first graft. Rejection was seen almost exclusively in patients exposed to multiple transfusions before transplantation. If patients who reject their first graft are censored, the overall incidence of grades II through IV acute graft-v-host disease (GVHD) was significantly reduced in those with mixed chimerism. Transfused patients with mixed chimerism in particular were less likely to develop grades II through IV acute GVHD. The incidence of chronic GVHD was similar in the two groups and did not significantly influence survival. In this study, mixed chimerism persisted for up to 395 days posttransplant, either the first graft being rejected or, more commonly, hematopoiesis reverting to 100% donor-type cells. Mixed lymphohematopoietic chimerism may persist in patients with aplastic anemia who have received matched allogeneic marrow transplants for significant periods before hematopoiesis reverts to donor cell type.     

Leukaemic transformation of donor cells in a patient receiving a second allogeneic bone marrow transplant for severe aplastic anaemia

Allogeneic blood or bone marrow transplantation is a successful treatment for leukaemia and severe aplastic anaemia (SAA). Graft rejection following transplantation for leukaemia is a rare event but leukaemic relapse may occur at varying rates, depending upon the stage of leukaemia at which the transplant was undertaken and the type of leukaemia. Relapse is generally assumed to occur in residual host cells, which are refractory to, or escape from the myeloablative conditioning therapy. Rare cases have been described, however, in which the leukaemia recurs in cells of donor origin. Lack of a successful outcome of blood or bone marrow transplantation for severe aplastic anaemia (SAA), however, is due to late graft rejection or graft-versus-host disease. Leukaemia in cells of donor origin has rarely been reported in patients following allogeneic bone marrow transplantation for SAA. This report describes leukaemic transformation in donor cells following a second allogeneic BMT for severe aplastic anaemia. PCR of short tandem repeats in bone marrow aspirates and in colonies derived from BFUE and CFU-GM indicated the donor origin of leukaemia. Donor leukaemia is a rare event following transplantation for severe aplastic anaemia but may represent the persistence or perturbation of a stromal defect in these patients inducing leukaemic change in donor haemopoietic stem cells.     

Case problems in bone marrow transplantation. I. Graft failure in aplastic anemia: its biology and treatment

An unusual case of graft failure following bone marrow transplantation for aplastic anemia is reported in which the patient had delayed and incomplete recovery of hematopoiesis despite documentation of sustained engraftment. The pathophysiology of graft failure following bone marrow transplantation is discussed and recent advances in pretransplant immunosuppressive therapy to prevent graft rejection are reviewed.     

Bone marrow transplantation for acquired aplastic anemia: What's new

Bone marrow transplantation is a major therapeutic option for patients with acquired severe aplastic anaemia: improved survival has been achieved in younger patients, thanks to better donor selection, conditioning regimens and graft versus host disease prophylaxis, together with improved supportive care, including diagnosis and treatment of opportunistic infections. This has not been the case for older patients over the age of 40 years.We will discuss transplantation platforms as used for different donor types and we will analyse major breakthroughs of the last years: the combination of Fludarabine and cyclophosphamide as a conditioning regimen, the use of alternative donors including HLA haploidentical related donors and new strategies to prevent acute and chronic graft versus host disease, including post transplantation Cyclophosphamide. These changes extend the option of a bone marrow transplantation for patients who lack an HLA matched donor and appear to improve engraftment and reduce graft versus host disease: whether this will be true for all age groups is currently being investigated.