Bone marrow transplantation for children with severe aplastic anemia: use of donors other than HLA-identical siblings

Eighty-five percent of untransfused and 70% of transfused patients with severe aplastic anemia (SAA) are cured with bone marrow transplants from histocompatible sibling donors. Use of partially matched family donors or unrelated donors has been relatively unsuccessful because of high incidences of graft rejection and graft-versus-host disease (GVHD). Thirteen children with SAA received marrow grafts from alternative donors (sibling 4, parent 5, unrelated 4). The first three patients were pretreated with cyclophosphamide (CYCLO) +/- irradiation and received methotrexate for GVHD prophylaxis. Subsequent children were pretreated with CYCLO + high-dose cytosine arabinoside + methylprednisolone + total body irradiation, had monoclonal antibody T- cell depletion of the donor marrow, and received cyclosporine for GVHD prophylaxis. Three heavily transfused patients with haploidentical- related donors failed to engraft and died. All 10 patients with more closely matched donors engrafted. Acute GVHD was grade II in only one patient (non-T-depleted); this patient is the only one with severe chronic GVHD. Three engrafted patients died (Pneumocystis pneumonia, systemic parainfluenza, venocclusive disease). Seven children are alive 33+ to 2,692+ days. Donors for the survivors were siblings 3, parent 1, unrelated 3. These data suggest that bone marrow transplantation from closely matched donors other than histocompatible siblings can be effective therapy for SAA if an intensive conditioning regimen is used. These results must be confirmed with larger numbers and longer follow- up.     

T-cell depletion of bone marrow transplants for leukemia from donors other than HLA-identical siblings: advantage of T-cell antibodies with narrow specificities

T-cell depletion of donor marrow decreases graft-versus-host disease resulting from transplants from unrelated and human leukocyte antigen (HLA)-mismatched related donors. However, there are diverse strategies for T-cell-depleted transplantation, and it is uncertain whether any improve leukemia-free survival (LFS). To compare strategies for T-cell-depleted alternative donor transplants and to compare T-cell depleted with non-T-cell-depleted transplants, we studied 870 patients with leukemia who received T-cell-depleted transplants from unrelated or HLA-mismatched related donors from 1982 to 1994. Outcomes were compared with those of 998 non-T-cell-depleted transplants. We compared LFS using different strategies for T-cell-depleted transplantation considering T-cell depletion technique, intensity of pretransplant conditioning, and posttransplant immune suppression using proportional hazards regression to adjust for other prognostic variables. Five categories of T-cell depletion techniques were considered: narrow-specificity antibodies, broad-specificity antibodies, Campath antibodies, elutriation, and lectins. Strategies resulting in similar LFS were pooled to compare T-cell-depleted with non-T-cell-depleted transplants. Recipients of transplants T-cell depleted by narrow-specificity antibodies had lower treatment failure risk (higher LFS) than recipients of transplants T-cell depleted by other techniques. Compared with non-T-cell-depleted transplants (5-year probability +/- 95% confidence interval [CI] of LFS, 31% +/- 4%), 5-year LFS was 29% +/- 5% (P = NS) after transplants T-cell depleted by narrow-specificity antibodies and 16% +/- 4% (P <.0001) after transplants T-cell depleted by other techniques. After alternative donor transplantation, T-cell depletion of donor marrow by narrow-specificity antibodies resulted in LFS rates that were higher than those for transplants T-cell depleted using other techniques but similar to those for non-T-cell-depleted transplants. (Blood. 2000;95:3996-4003)     

Bone marrow transplantation from HLA-identical siblings as treatment for myelodysplasia

Allogeneic hematopoietic stem cell transplantation is the only curative therapy for myelodysplasia (MDS). To identify factors influencing transplantation outcome, we studied 452 recipients of HLA-identical sibling transplants for MDS from 1989 to 1997, reported to the International Bone Marrow Transplant Registry. Patients with treatment-related MDS or unclassified MDS were excluded. Median age was 38 years (range, 2-64 years). Sixty percent had refractory anemia with excess blasts (n = 136) or with excess blasts in transformation (n = 136). Conditioning regimens included total body irradiation in 199 (44%) cases. Marrow was T-cell depleted for 58 (13%) transplants. Cumulative incidences of neutrophil engraftment, grades II-IV acute graft-versus-host disease (GVHD), and chronic GVHD were 91% (95% confidence interval [CI], 88%-93%), 36% (95% CI, 31%-40%), and 39% (95% CI, 33%-44%), respectively. Three-year transplantation-related mortality (TRM), relapse, disease-free survival, and overall survival rates were 37% (95% CI, 32%-42%), 23% (95% CI, 19%-27%), 40% (95% CI, 36%-45%), and 42% (95% CI, 37%-47%), respectively. Multivariate analyses showed that young age and platelet counts higher than 100 x 10(9)/L at transplantation were associated with lower TRM and higher disease-free and overall survival rates. Relapse incidence was higher in patients with high percentages of blasts in the marrow at transplantation or presentation, with high International Prognostic Scoring System scores at diagnosis, and with T-cell-depleted transplants. These findings indicate that transplantation from an HLA-identical sibling offers the possibility of long-term, disease-free survival to patients with MDS. Best candidates are younger patients with a low percentage of blasts and preserved platelet counts.     

Allogeneic marrow transplantation using T cell depletion for patients with juvenile chronic myelogenous leukemia without HLA-identical siblings.

Six children with clinical and hematologic features of juvenile chronic myelogenous leukemia (JCML) underwent bone marrow transplantation (BMT) using T cell-depleted marrow from non-HLA-matched related or closely HLA-matched unrelated donors. Patient ages ranged from 1.2 to 5 years. Four patients received cytoreductive chemotherapy prior to BMT conditioning, and four had undergone pretransplant splenectomies. The donor-recipient matching included: four transplants disparate at one HLA locus (three from unrelated donors and one from a related donor), one transplant disparate at two HLA loci, and one transplant from a one haplotype-mismatched donor. All patients were MLC reactive with their donors. Graft-versus-host disease (GVHD) prophylaxis consisted of in vitro T cell depletion with a monoclonal antibody directed against CD3, and complement in conjunction with cyclosporin A begun on day -1. Conditioning included busulfan, cytosine arabinoside, cyclophosphamide, methyl-prednisolone, and hyperfractionated total body irradiation. All patients engrafted, with median time to neutrophils greater than 500 x 10(6)/l and platelets greater than 25 x 10(9)/l of 20 and 21 days, respectively. Acute GVHD was less than or equal to grade II in all patients. Two patients died of infection (Candida, CMV) at days 74, 157. One patient relapsed at day 177, and subsequently died on day 939. Three patients are alive and disease free at 180 +, 1610 + and 2400 + days from BMT. Although intensive chemotherapy may play a role in providing transient disease control in patients with JCML, allogeneic BMT is the only curative therapy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bone marrow donors other than HLA genotypically identical siblings for patients with thalassemia

This report describes the successful bone marrow transplantation of three children with thalassemia who received bone marrow, one from an HLA identical but mixed lymphocyte culture-reactive sibling, the other two from an HLA phenotypically identical parent. Evidence of engraftment was detected early (19-21 days) in all three children and only grade II acute GvHD was observed in one patient. Our report indicates that thalassemic patients can be cured by bone marrow transplantation from selected donors other than HLA genotypically identical siblings.     

Bone marrow transplantation for severe aplastic anemia from donors other than HLA identical siblings: a report of the BMT Working Party

Data were obtained from 46 patients with severe aplastic anemia (SAA) who received bone marrow transplants (BMT) from donors other than genotypically HLA-identical siblings. The data were collected in the SAA Registry of the European Bone Marrow Transplant Group. The donors were non-HLA-identical siblings in six cases, parents in 28 cases, a son in one case and unrelated individuals in 11 cases. Fifteen donor-recipient pairs were HLA-A, -B and -DR identical and mutually non-reactive in mixed lymphocyte culture; nine were mismatched at one locus, 17 were mismatched at two or more loci and in five cases data were not available for D/DR determinants. Actuarial survival was predicted by the degree of mismatch. It was 45% for phenotypically HLA-identical grafts, 25% for grafts mismatched at one locus and 11% for graft mismatched at more than one locus. Whether the graft was derived from a family member or an unrelated donor seemed to be less important and results were comparable. Age, patient sex and year of transplant had no significant influence on survival. The use of cyclosporine (CSA) for graft-versus-host disease (GVHD) prophylaxis (n = 21, survival 34%) appeared superior to both methotrexate (n = 9, survival 11%) and to CSA with T cell depletion of donor marrow (n = 13, survival 14%). The causes of death were rejection (n = 15), GVHD (n = 13), pneumonitis (n = 5) and infection (n = 1). Twelve patients are alive at 16-84 months post-BMT.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hematopoietic stem cell transplantation: contrasting the outcome of transplantations from HLA-identical siblings,partially HLA-mismatched related donors,and HLA-matched unrelated donors

Allogeneic hematopoietic stem cell transplantation (HSCT) is a proven curative therapy for many hematologic malignancies. HSCT from HLA-identical sibling donors (ISDs) is still the golden standard. For the remaining 70% of the patients lacking an ISD, alternative (partially) HLA-matched family donors (MFDs) and HLA-matched unrelated donors (MUDs) are now widely accepted. However, it is presently unclear whether outcome after HSCT from an MFD or an MUD is superior. Thus, the classical clinical end points after HSCT from an ISD (n = 138), MFD (n = 86), and MUD (n = 101) were compared by means of univariate and multivariate statistical analyses. MFD transplantations with HLA class II (DRB1 +/- DQB1) mismatches in graft-versus-host (GVH) direction showed an increased risk of grades II to IV graft-versus-host disease, and MFD transplantations with more than a single HLA class I (A +/- B +/- C) mismatch in host-versus-graft (HVG) direction were associated with a higher risk of graft failure. However, no significant difference in overall survival was detectable among the 3 study groups after adjustment for the main predictors of transplantation outcome. Thus, for patients lacking an ISD, an already identified MFD with an HLA-DRB1 +/- DQB1 mismatch in GVH or a combined HLA-A +/- B +/- C mismatch in HVG direction should be accepted only in clinically urgent settings that leave no time to identify an MUD.     

Bone marrow from cadaver donors for transplantation

To determine the feasibility of obtaining bone marrow cells from cadaver donors for transplantation, marrow cells were prepared from 17 cadaver donors. After surgical removal of the iliac crest, as many as 2 X 10(9) cells were isolated. Cadaver marrow had a lower percentage of T cells (mean of 10%) than did marrow from living donors. The T cells were lysed by a monoclonal antibody and human complement to a point at which no sheep red blood cell-rosetting cells were detected. Low levels of T colonies, however, grew out from the monoclonal antibody-treated cells. Although cell loss inevitably occurs from purification, antibody treatment, freezing, and thawing, sufficient numbers can be recovered for transplantation. The yield of stem cells was 84% for CFU-C, 39% for CFU-E, 81% for BFU-E, and 48% for CFU-GEMM. We suggest that T cell- depleted marrow cells from cadaver donors could be used for transplantation. Improved immunosuppressive therapy may be required, however, to prevent graft rejection of allogeneic marrow that may have minor histocompatibility differences.     

T cell depletion in bone marrow transplantation

Prior to the introduction of T cell depletion graft-versus-host disease (GVHD) was the major cause of transplant-related mortality. Why has the remarkable technical achievement of efficient T cell depletion, which has virtually eliminated severe GVHD over the last few years, failed to reduce mortality and increase disease-free survival? This review examines the value of T cell depletion based on recent clinical experience. It surveys the directions that are being pursued in an effort to solve the problems that have arisen and indicates how this is leading to a greater understanding of the mechanisms involved in GVHD and the graft-versus-leukaemia effect.     

Allogeneic hematopoietic stem cell transplantation from family members other than HLA-identical siblings over the last decade (1991-2000)

The reported outcome of hematopoietic stem cell transplantation (HSCT) from HLA-mismatched family members has been inconsistent. The object of this study was to evaluate the true impact of HLA-mismatch by using recent data from a homogenous population, excluding HSCT procedures that used graft manipulations, and by considering genotypic matching. Clinical data of 2947 patients who underwent allogeneic HSCT for leukemia or myelodysplastic syndrome were extracted from the database of the Japan Society for Hematopoietic Cell Transplantation. The main outcome measures were survival and the incidence of graft-versus-host disease (GVHD). The presence of serologic HLA-mismatch, higher age, and high-risk disease were identified as independent risk factors for both shorter survival and the development of grade III to IV acute GVHD. The impact of HLA-mismatch on survival was more relevant in standard-risk patients. These findings persisted when we used genotypic HLA matching. Survival after one-locus-mismatched HSCT was equivalent to that after HLA-matched unrelated HSCT. We concluded that when a one-locus-mismatched family donor is available for high-risk patients, immediate HSCT using this donor is warranted. In standard-risk patients, however, survival after one-locus-mismatched HSCT is significantly shorter than that after HLA-matched HSCT, and the indications for HSCT should be considered carefully.     

Cyclophosphamide and antithymocyte globulin conditioning may be sufficient for Korean patients with early stage severe aplastic anemia transplanted with marrow from donors other than HLA-identical siblings

We gave a regimen of cyclophosphamide and antithymocyte globulin (CY/ATG) to six patients with early stage severe aplastic anemia (SAA) transplanted with marrow from alternative donors. All patients engrafted and are alive with durable engraftment at a median follow-up of 406 days. The CY/ATG regimen may be sufficient in Korean patients with early stage SAA receiving marrow transplantation from alternative donors.     

Using related donors other than genotypically HLA-matched siblings in allogeneic hematopoietic stem cell transplantation for hematologic disease: a single institution experience in Japan

Thirty patients with hematologic diseases received allogeneic hematopoietic stem cell transplants (HSCT) from related donors other than genotypically HLA-matched siblings. Their outcomes were compared with those of 102 patients who had received HSCT from genotypically HLA-matched siblings. All donors in the study group were HLA-haploidentical relatives, The degree of HLA mismatches in unshared haplotype was 0-locus (n = 6), 1-locus (n = 20), and 2-locus (n = 4). All patients in the study group achieved successful engraftment at a median of 17 days (range, 10-35 days). Grade II-IV and ITI-IV acute graft-versus-host disease (GVHD) occurred in 16 (53%) and 9 (30%) patients, respectively, in the study group, rates that were significantly higher than those of the control group, which were 33 (33%) and 12 (12%) patients, respectively (P = .034 and .022, respectively). The frequency of chronic GVHD was 85% (22 out of 26 evaluable patients) in the study group, a rate that was also significantly higher than that of the control group with 57% (52 of 91 patients) (P = .0078). The estimated probability of disease-free survival (DFS) for the study group was 56% at 5 years. When the 2 groups were compared according to the risk of disease, the probabilities of DFS at 5 years for patients with low risk in the study and for control groups were 100% and 84%, respectively, and those for patients with high risk were 43% and 42%, respectively.These results showed that the DFS for patients with both low and high risks in the study group was comparable to that of the control group. In conclusion, despite higher probabilities of acute and chronic GVHD, unmanipulated allogeneic HSCT from related donors other than genotypically HLA-matched siblings was considered to be a reasonable alternative for patients without genotypically HLA-matched sibling donors.     

Cytotoxic T lymphocyte precursor frequency as a predictor of acute graft-versus-host disease in bone marrow transplantation from HLA-identical siblings

The measurement of precursor frequencies of donor anti-recipient cytotoxic T lymphocytes (CTL-p) has been shown to predict the incidence and the severity of acute graft-versus-host disease (aGVHD) in unrelated donor bone marrow transplantation (BMT). In HLA-identical sibling BMT, where aGVHD is most likely caused by minor histocompatibility antigen mismatches, this assay did not appear to be sensitive enough to provide similar predictive information. In this study, the CTL-p frequencies and the incidence and severity of aGVHD in 51 onco-hematological patients transplanted from HLA-identical siblings were compared. Sibling donors were selected on the basis of HLA identity using serological typing for HLA-A, B, C antigens, whereas HLA-DRB was tested by molecular analysis. Sibling identity was also confirmed by DNA heteroduplex analyses. Fifteen out of 21 (71%) patients with high precursor frequency (>1:100 x 10(3)) and 12 out of 30 (40%) with low precursor frequency (<1:100 x 10(3)) experienced clinically significant (II-IV) aGVHD. A significant correlation (P = 0.04) between CTL-p frequency and severe aGVHD was demonstrated. Moreover there was a positive trend for a high frequency response according to an increasing grade of aGVHD, which was statistically significant (P = 0.04). In our experience the CTL-p assay is a helpful predictive test for aGVHD in HLA-identical sibling BMT, indicating high risk patients possibly requiring additional prophylaxis.     

Bone marrow as stem cell source for allogeneic HLA-identical sibling transplantation following reduced-intensity preparative regimen

OBJECTIVE: Reduced-intensity conditioning regimens (RIC) and peripheral blood stem cells (PBSC) are increasingly used for allogeneic stem cell transplantation (allo-BMT). RIC has been shown to allow engraftment with minimal early transplant-related mortality (TRM). However, in the context of RIC, the use of bone marrow (BM) as stem cell source is still little evaluated. PATIENTS AND METHODS: In this report, we analyzed the outcome of 32 high-risk patients with hematological malignancies who received an HLA-identical sibling allo-BMT after RIC including fludarabine, busulfan, and anti-thymocyte globulin (ATG). RESULTS: Sustained neutrophil and platelet recovery occurred at a median of 13 days (range, 10-19) and 17 days (range, 0-45) respectively. Early and durable full donor chimerism could be established as soon as the first month after allo-BMT. Also, a sustained and early CD8(+) T-cell recovery was observed, but the CD4(+) T-cell compartment remained profoundly low. The cumulative incidences of grade II-IV acute GVHD and chronic GVHD were 26% (95% CI, 11-41%) and 31% (95% CI, 15-47%) respectively. The overall cumulative incidence of TRM was 28% (95% CI, 12-44%) occurring mainly in patients aged over 50. In this setting, GVHD showed a protective effect on disease progression or relapse with better progression-free survival for patients with GVHD as compared to patients without GVHD (p=0.03). CONCLUSIONS: Collectively, these results confirm that the use of BM grafts for RIC is feasible with durable donor engraftment and no detrimental GVHD.     

Allogeneic bone marrow transplantation with non-T-cell-depleted marrow from two HLA-antigen-mismatched related donors

Allogeneic BMT from 2 antigen-mismatched donors has been difficult to perform without T-cell depletion. Seven patients with advanced-stage hematologic malignancies underwent BMT with intensified graft-versus-host disease prophylaxis consisting of tacrolimus, methotrexate, and methylprednisolone. No rejection or acute GVHD >or= grade III was observed. This preliminary result is very promising.     

Graft-versus-host disease following transplantation of 'one log' versus 'two log' T-lymphocyte-depleted bone marrow from HLA-identical donors

Prevention of acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation, requires the depletion of mature T-lymphocytes from bone marrow grafts. The optimal degree of T-cell reduction is still an open question. We compared two procedures of T-cell separation in 18 consecutive recipients of genotypically HLA-matched bone marrow, who also received cyclosporin A for 6 months. The first method (A) was based on a discontinuous albumin gradient fractionation and resulted in an average T-lymphocyte content of 50 X 10(5)/kg body weight (n = 9 patients); the second method (B) was based on E-rosette sedimentation and reduced the contamination to 15 X 10(4) grafted T-lymphocytes/kg body weight on the average (n = 9 patients). Thus, approximately 90 and 99% of the original T-lymphocytes were removed from the marrow grafts respectively. Of the seven patients of the first group who were at risk of GVHD (excluding two cases of early death), five developed a minimal-to-moderately severe acute GVHD and in two cases chronic GVHD ensued. Lethal GVHD was not seen. Of group B, all recipients engrafted and none developed GVHD (0/9). The difference in the frequency of GVHD between the two groups was highly significant (P less than 0.0025). These data confirm our preclinical studies. They demonstrate that a one-log T-lymphocyte reduction of the marrow inoculum, when combined with cyclosporin A prophylaxis after major histocompatibility complex (MHC)-matched transplantation, is still associated with a considerable incidence of GVHD, whereas a two-log reduction of T-lymphocytes may provide full protection against acute GVHD.     

Interferon-gamma-based mixed lymphocyte culture as a selection tool for allogeneic bone marrow donors other than identical siblings

Selection procedures in bone marrow transplantation (BMT) would benefit from the development of easy-to-perform cellular assays with high discriminative power. We tested a cytokine-based mixed lymphocyte culture (MLC) and compared its outcome to the routinely used MLC, helper T-lymphocyte precursor (HTLp)-f and cytotoxic T-lymphocyte precursor (CTLp)-f assays. Interferon (IFN)gamma was selected as a marker cytokine for (deleterious) T-helper 1 like responses and 36 (potential) BMT donor-recipient pairs were analysed. The IFNgamma-MLC appeared sensitive to HLA class II (subtype) differences, but not to isolated class I differences, or to mismatches other than HLA (identical siblings). The test enabled a distinction between combinations with positive MLC (proliferation) and HTLp-f, exemplified by the fact that although high IFNgamma levels were observed in the class II mismatched group, certain DRB3, DQB1-subtype and DRB1-subtype mismatches did not give rise to IFNgamma production. This might be of relevance for the detection of so-called permissible mismatches. With regard to prediction of acute graft-versus-host disease (aGVHD) in unrelated BMT, the data indicated that high levels of IFNgamma coincided with severe aGVHD, whereas low levels were largely associated with grades 0-I. However, in the case of isolated class I mismatches the test had no predictive value. The cell-saving IFNgamma-MLC provides an alternative for the assays currently in use, but should be employed along with an assay that is sensitive to class I differences to correct for false negatives. Consequently, a combination of IFNgamma-MLC and CTLp-f assays seems most promising for donor selection, other than identical siblings.