HLA-identical Sibling Marrow Research Articles

Phase III Study Comparing Methotrexate and Tacrolimus (Prograf, FK506) With Methotrexate and Cyclosporine for Graft-Versus-Host Disease Prophylaxis After HLA-Identical Sibling Bone Marrow Transplantation

We report the results of a phase III open-label, randomized, multicenter trial comparing tacrolimus/methotrexate to cyclosporine/methotrexate for graft-versus-host disease (GVHD) prophylaxis after HLA-identical sibling marrow transplantation in patients with hematologic malignancy. The primary objective of this study was to compare the incidence of moderate to severe (grade II-IV) acute GVHD. Secondary objectives were to compare the relapse rate, disease-free survival, overall survival, and the incidence of chronic GVHD. Patients were stratified according to age (<40 v ≥40) and for male recipients of a marrow graft from an alloimmunized female. There was a significantly greater proportion of patients with advanced disease randomized to tacrolimus arm (P = .02). The incidence of grade II-IV acute GVHD was significantly lower in patients who received tacrolimus than patients in the cyclosporine group (31.9% and 44.4%, respectively; P = .01). The incidence of grade III-IV acute GVHD was similar, 17.1% in cyclosporine group and 13.3% in the tacrolimus group. There was no difference in the incidence of chronic GVHD between the tacrolimus and the cyclosporine group (55.9% and 49.4%, respectively; P = .8). However, there was a significantly higher proportion of patients in the cyclosporine group who had clinical extensive chronic GVHD (P = .03). The relapse rates of the two groups were similar. The patients in the cyclosporine arm had a significantly better 2-year disease-free survival and overall survival than patients in the tacrolimus arm, 50.4% versus 40.5% (P = .01) and 57.2% versus 46.9% (P = .02), respectively. The significant difference in the overall and disease-free survival was largely the result of the patients with advanced disease, 24.8% with tacrolimus versus 41.7% with cyclosporine (P = .006) and 20.4% with tacrolimus versus 28% with cyclosporine (P = .007), respectively. There was a higher frequency of deaths from regimen-related toxicity in patients with advanced disease who received tacrolimus. There was no difference in the disease-free and overall survival in patients with nonadvanced disease. These results show the superiority of tacrolimus/methotrexate over cyclosporine/methotrexate in the prevention of grade II-IV acute GVHD with no difference in disease-free or overall survival in patients with nonadvanced disease. The survival disadvantage in advanced disease patients receiving tacrolimus warrants further investigation.

Should Methotrexate plus Calcineurin Inhibitors Be Considered Standard of Care for Prophylaxis of acute Graft-versus-Host Disease?

In a rapidly developing field, one can always anticipate that different interpretations of similar data will coexist. Stem cell transplanters can be a contentious lot, especially in the absence of controlled randomized trials. Thus, although improvements in the basic understanding of acute graft-versus-host disease (aGVHD) has led to many testable hypotheses in the management of GVHD, there remains little consensus regarding the most effective and least toxic approach to GVHD prevention. In the 1980s, the comparison would have been between cyclosporine-based regimens and ex vivo T cell depletion (TCD). Although ex vivo TCD is still used in some settings, pharmacologic-based therapy and in vivo TCD with serotherapy now predominate. This review is meant to highlight the advantages and disadvantages of the "standard of care" and assess the prospects for future regimens that may be more effective.

Late Mortality and Relapse following BuCy2 and HLA-Identical Sibling Marrow Transplantation for Chronic Myelogenous Leukemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only known curative therapy for chronic myelogenous leukemia (CML). Failure, because of relapse or nonrelapse mortality (NRM), generally occurs within 3 years of transplantation, but large studies with long-term follow-up are limited. We present mature results in 335 patients with CML who underwent allogeneic bone marrow transplantation (BMT) from HLA-identical siblings following busulfan and cyclophosphamide (BU/Cy2). Two hundred twenty-nine were in chronic phase (CP) and 106 in accelerated or blastic phase at transplantation. Median follow-up exceeded 14 years. The estimated probability of 18-year leukemia-free survival (LFS) for CP patients was 55.6% and for those beyond CP, 10.5%. Of 182 patients who survived leukemia-free at 3 years, the estimated probability of LFS at 18 years was 61.9%. Late relapse (P = .039) and late NRM (P = .008) occurred at higher rates in patients beyond CP at transplantation. There was no plateau in LFS.

A decade of myeloablative hla-matched sibling marrow transplantation for children with severe sickle cell disease: outcomes and lessons learned from the Atlanta experience

Allogeneic BMT offers a cure to select patients with sickle cell disease (SCD), but the limited available long-term data and concerns about the risk-to-benefit ratio present dilemmas for families and clinicians. We report favorable outcomes in a large single institution experience with myeloablative matched sibling BMT for children with severe SCD between December 1993 and April 2003. Sixteen patients (12 male) with a median age 7.7 years (3.3–17.1) were transplanted for primary indications of CVA (n = 8), recurrent TIA (n = 1), recurrent ACS (n = 6), and frequent VOC pain (n = 1). Graft source was HLA-identical sibling marrow, with 9 HgbAS donors. Preparative regimen (BU 14 mg/kg, CTX 200 mg/kg, ATG 90 mg/kg) was well tolerated. Special measures included aggressive management of hypertension and hypomagnesemia, maintenance of Hgb 10–12 g/dl and platelets >50k, and prolonged antiepileptics while on CSA for GVHD prophylaxis. The initial 8 patients were treated on a multicenter consortium trial (Walters et al). With median follow-up 36 months (6–84), OS and DFS are 100% and there are no graft failures. Two patients have stable mixed chimerism (72 and 69% donor) with low HgbS (0 and 2.5%) and no clinical SCD. Median WBC engraftment was day 12.5 (10–21) and platelet engraftment day 31.5 (17–46). No patients experienced aGVHD. The two oldest patients had cGVHD related to medication non-compliance. Two of the 8 patients with prior CVA had serious CNS events, including seizure and hemorrhage on day 0 in a moya-moya patient and late progressive cerebrovascular disease in a patient with prior CVA. None had new clinical CVA. One patient (age 16.7 years) without prior CVA had a seizure attributed to “non-compliance rebound” with CSA. Infections included two episodes of Zoster, one early multiorganism bacteremia, and one late pneumococcal bacteremia. All patients have excellent functional status and attend school/college. These favorable outcomes have led our center to offer this transplant treatment as a standard-of-care with principles specific to SCD: 1)careful psychosocial screening and transplantation at a young age, 2)supportive measures to avoid CNS events, and 3) long-term follow-up with attention to infection and cerebrovascular disease that may relate to SCD rather than the BMT. In our experience, collaborative management with a comprehensive sickle cell program optimizes referral of appropriate patients, reduces peritransplant complications, and optimizes outcomes.

Clinical tolerance after allogeneic hematopoietic stem cell transplantation: a study of influencing factors.

Clinical tolerance, defined as discontinuation of immunosuppression without immunological events, is often achieved after allogeneic hematopoietic stem cell transplantation, unlike after organ transplantation. However, this phenomenon has rarely been studied. Between September 1977 and December 1997, we evaluated 354 allogeneic hematopoietic stem cell recipients who had had more than 1 year of relapse-free survival, regarding time to discontinuation of immunosuppression. Factors such as patient age, donor age, donor sex, immunosuppressive protocols, cell dose, and graft-versus-host-disease (GVHD) were studied. Patients who did not develop GVHD had discontinued immunosuppression according to the protocols, within 1 year for malignant diseases and within 2 years for nonmalignant diseases. Patients given methotrexate as a single drug were off immunosuppression faster than those given cyclosporine alone (P=0.05). Children (<18 years) discontinued immunosuppression faster than adults (P=0.05). Low donor age was of greater importance than low recipient age for early discontinuation (P=0.003). Male recipients of stem cells from immunized female donors needed a longer time to discontinuation (P<0.001). Patients without acute GVHD had a shorter time to discontinuation than patients with any grade of GVHD (P=0.02). Thirteen months after hematopoietic stem cell transplantation, 54% of HLA-identical sibling marrow recipients and 36% of unrelated marrow recipients with malignant disease had discontinued immunosuppression (P=0.002). Twenty-five months after hematopoietic stem cell transplantation, the corresponding figures were 69% and 75% in the two groups, respectively. In multivariate analysis, high donor age, immunized female donor to male recipient, and grades II-IV acute GVHD were significantly associated with a longer time to clinical tolerance.

T-cell depletion plus salvage immunotherapy with donor leukocyte infusions as a strategy to treat chronic-phase chronic myelogenous leukemia patients undergoing HLA-identical sibling marrow transplantation: W.R. Drobyski, M.J. Hessner, J.P. Klein, et al. Blood 94:434–441, 1999

T-cell depletion plus salvage immunotherapy with donor leukocyte infusions as a strategy to treat chronic-phase chronic myelogenous leukemia patients undergoing HLA-identical sibling marrow transplantation: W.R. Drobyski, M.J. Hessner, J.P. Klein, et al. Blood 94:434–441, 1999

The association between incompatibility of CD31 genotypes and acute graft-versus-host disease in hla-identical sibling marrow transplants

Graft-versus-host disease (GVDH) in recipients of HLA-identical bone marrow transplant (BMT) has been attributed to incompatibility between minor histocompatibility antigens. CD31/PECAM-1 (platelet-endothelial-cell adhesion molecule 1) is the most polymorphic adhesion molecule which has four amino acid substitution located at codons 80, 125, 563, and 670. We investigated the clinical relevance of the CD31 Leu→Val polymorphism in 70 patients who had received bone marrow from sibling donors with HLA-identical genotypes. Association of the incompatibility of CD31 genotypes with the presence (n = 30) or absence (n = 40) of acute GVHD was examined.Our data suggest that incompatibility of CD31 genotypes between donor and recipient will contribute the risk of GVHD development after HLA-identical sibling BMT.

Low-dose cyclosporine of short duration increases the risk of mild and moderate GVHD and reduces the risk of relapse in HLA-identical sibling marrow transplant recipients with leukaemia.

Low-dose cyclosporine (CsA), starting at 1 mg/kg/day i.v. with early discontinuation, and four doses of methotrexate (MTX), was given to 82 consecutive leukaemic patients receiving HLA-identical sibling marrow transplants. Retrospective controls (n = 40) received CsA, starting at 5-7.5 mg/kg/day i.v., given for 1 year, and MTX. In the low-dose group, the risk of acute GVHD grades I-II was 78% as compared to 57% among the controls (P < 0.01). The risk of acute GVHD grades III-IV was 2% and 5%, respectively (NS). Chronic GVHD occurred in 60% in the low-dose group and 24% in the controls (P < 0. 001). Extensive chronic GVHD did not differ between the groups (3% vs6%). In multivariate analyses, low-dose CsA was the only factor associated with acute GVHD grades I-IV (P = 0.02). Significant risk factors for chronic GVHD included low-dose CsA (P = 0.002) and CML (P = 0.03). Transplant-related mortality at 3 years post-BMT was 22% and 19%, in the low-dose group and controls, respectively (NS). The probability of relapse was 26% in the low-dose group and 53% in the controls (P = 0.06). In multivariate analysis, high-dose CsA was the strongest risk factor for relapse (P = 0.03). The 3-year relapse-free survival was 58% in the low-dose group and 43% in the controls (P = 0.1).

T-Cell Depletion Plus Salvage Immunotherapy With Donor Leukocyte Infusions as a Strategy to Treat Chronic-Phase Chronic Myelogenous Leukemia Patients Undergoing HLA-Identical Sibling Marrow Transplantation

T-cell depletion (TCD) of the donor marrow graft has been shown to reduce the severity of graft-versus-host disease (GVHD) in patients with chronic-phase (CP) chronic myelogenous leukemia (CML) undergoing HLA-identical sibling allogeneic marrow transplantation. However, there has been a corresponding reduction in the graft-versus-leukemia effect so that any decrease in GVHD-related mortality has been offset by an increased rate of disease relapse. Therapy of recurrent disease with donor leukocyte infusions (DLI) has been proven to be effective salvage therapy for the majority of patients who relapse after allogeneic BMT with CP CML. However, the overall impact of salvage DLI therapy on the survival of CP CML patients initially transplanted with TCD marrow grafts is not defined. To address this question, we have evaluated a clinical strategy of TCD followed by targeted adoptive immunotherapy with DLI in 25 CP CML patients undergoing allogeneic BMT from HLA-identical siblings. All patients received a standardized preparative regimen along with ex vivo TCD and posttransplant cyclosporine as GVHD prophylaxis. Durable engraftment was observed in all 25 patients. The incidence of grade II to IV acute GVHD was 8%. The cumulative incidence of transplant-related mortality (TRM) was 4%, and the 1-year probability of overall survival was 96%. The 3-year cumulative relapse incidence was 49%. All relapsed patients received DLI to reinduce remission. The total T-cell dose administered to these patients varied from 0.1 to 5.0 × 108 T cells/kg. Complete responses were observed in 12 of 14 patients, with 1 additional patient still too early to evaluate. Three patients died of GVHD after DLI, and 1 relapsed into blast crisis after a transient cytogenetic remission. Of the remaining 10 patients, 8 are in molecular remission, 1 is alive in relapse, and 1 is receiving DLI treatment. The median follow-up after infusion of surviving DLI patients in remission is 5.3 years. The probability of overall 5-year survival for the entire population is 80%, with a median follow-up of 6.4 years. We conclude that the clinical strategy of TCD followed by targeted adoptive immunotherapy with DLI for those patients with evidence of recurrent disease is a viable transplant strategy for CP CML, resulting in 80% survival and a low risk of acute GVHD and transplant-related mortality.

T-Cell Depletion Plus Salvage Immunotherapy With Donor Leukocyte Infusions as a Strategy to Treat Chronic-Phase Chronic Myelogenous Leukemia Patients Undergoing HLA-Identical Sibling Marrow Transplantation

AbstractT-cell depletion (TCD) of the donor marrow graft has been shown to reduce the severity of graft-versus-host disease (GVHD) in patients with chronic-phase (CP) chronic myelogenous leukemia (CML) undergoing HLA-identical sibling allogeneic marrow transplantation. However, there has been a corresponding reduction in the graft-versus-leukemia effect so that any decrease in GVHD-related mortality has been offset by an increased rate of disease relapse. Therapy of recurrent disease with donor leukocyte infusions (DLI) has been proven to be effective salvage therapy for the majority of patients who relapse after allogeneic BMT with CP CML. However, the overall impact of salvage DLI therapy on the survival of CP CML patients initially transplanted with TCD marrow grafts is not defined. To address this question, we have evaluated a clinical strategy of TCD followed by targeted adoptive immunotherapy with DLI in 25 CP CML patients undergoing allogeneic BMT from HLA-identical siblings. All patients received a standardized preparative regimen along with ex vivo TCD and posttransplant cyclosporine as GVHD prophylaxis. Durable engraftment was observed in all 25 patients. The incidence of grade II to IV acute GVHD was 8%. The cumulative incidence of transplant-related mortality (TRM) was 4%, and the 1-year probability of overall survival was 96%. The 3-year cumulative relapse incidence was 49%. All relapsed patients received DLI to reinduce remission. The total T-cell dose administered to these patients varied from 0.1 to 5.0 × 108 T cells/kg. Complete responses were observed in 12 of 14 patients, with 1 additional patient still too early to evaluate. Three patients died of GVHD after DLI, and 1 relapsed into blast crisis after a transient cytogenetic remission. Of the remaining 10 patients, 8 are in molecular remission, 1 is alive in relapse, and 1 is receiving DLI treatment. The median follow-up after infusion of surviving DLI patients in remission is 5.3 years. The probability of overall 5-year survival for the entire population is 80%, with a median follow-up of 6.4 years. We conclude that the clinical strategy of TCD followed by targeted adoptive immunotherapy with DLI for those patients with evidence of recurrent disease is a viable transplant strategy for CP CML, resulting in 80% survival and a low risk of acute GVHD and transplant-related mortality.

Engraftment of marrow allografts treated with Campath-1 monoclonal antibodies

We have analyzed the factors associated with engraftment in 216 recipients of T-cell depleted allogeneic HLA identical sibling marrow transplants using Campath 1 monoclonal antihuman lymphocyte (CD52) antibodies. The patient population consisted of 168 patients with hematologic malignancies, 26 with severe aplastic anemia (SAA), and 22 with hemoglobinopathies, half of whom received marrow treated in vitro with Campath-1M (IgM) and half received marrow with Campath-1G (IgG2b isotype). Patients with durable engraftment had fast hematopoietic recovery: SAA patients reached ANC > 0.5×10 6/L on Day 14; those with leukemia attained ANC > 0.5×10 6/L on Days 18, 17, and 15 for ANLL, ALL and CML respectively, while patients with thalasemia reached ANC > 0.5×10 6/L on Day 21. Overall, 24 patients (17 with leukemia, 4 with SAA, and 3 with thalassemia) suffered graft failure: 10 patients (all grafted with Campath-1M) rejected their grafts, while 14 others (9 grafted with Campath-1M, and 5 with 1G isotype) never engrafted ( p = 0.009). Multivariate analysis revealed that neither pretransplant protocol, nor stage of disease or type of antibody used, donor sex and ABO match had any impact on engraftment. The variables favorably associated with engraftment were older age ( p = 0.030, RR = 1.016) and CFU-GM number ( p = 0.013, RR = 1.001). Patients with ANLL or SAA had a better chance to engraft ( p = 0.027, RR = 1.400; and p = 0.003, RR = 2.677, respectively) compared to patients with thalassemia ( p = 0.001, RR = 0.551). A higher concentration of Campath-1 antibody in vitro and in vivo adversely affected engraftment. Our data show that satisfactory engraftment can be achieved in patients transplanted with Campath-1 treated marrow allografts. However, despite the measures undertaken to prevent rejection, graft failure still poses a problem. Further pretransplant immunosuppression and perhaps more selective T-cell depletion may reduce the increased graft failure in these patients.

Helper and cytotoxic T cell precursor frequencies are not predictive for development of acute graft-versus-host disease after partially T cell-depleted HLA-identical sibling BMT.

Despite the use of partially T cell-depleted grafts, 20% of the recipients of an HLA-identical sibling marrow graft develop aGVHD > or = II. This indicates that the current method for selecting a sibling donor, ie serological typing for HLA-A, B and DR, and a mixed lymphocyte culture (MLC) or molecular typing for HLA-DRB/DQB, is not predictive for aGVHD. In order to optimise our selection procedure, we retrospectively analysed patients who developed aGVHD > or = II by means of sequencing based typing for HLA-DPB and frequency analysis of alloreactive helper and cytotoxic T lymphocyte precursors (HTLp-f and CTLp-f). Patients who did not develop aGVHD or developed aGVHD grade I served as controls. Retrospective typing for HLA-DPB revealed only a single disparity in the group with aGVHD > or = II, indicating that mismatches for antigens other than HLA are the major cause of aGVHD in these patients. Furthermore, in our patient group, neither HTLp-f nor CTLp-f were predictive for development of aGVHD indicating that these assays in their current set-up are insufficiently sensitive to predict aGVHD in BMT with a partially T cell-depleted graft. We conclude, that HLA-identical siblings can be identified by means of serological typing for HLA-A and B and intermediate resolution molecular typing for DRB and DQB, but that for the prediction of aGVHD cellular tests with higher sensitivity and specificity as compared to the currently used HTLp-f and CTLp-f assays need to be developed.

Unrelated and HLA-nonidentical related donor marrow transplantation for thalassemia and leukemia. A combined report from the Seattle Marrow Transplant Team and the International Bone Marrow Transplant Registry.

Allogeneic marrow transplantation is curative therapy for thalassemia, but fewer than 30% of patients have an HLA-identical sibling marrow donor. Selection of alternative donors of hematopoietic stem cells (unrelated individuals or HLA-nonidentical family members) has been aided by establishment of world-wide donor registries now exceeding 3.6 million volunteers and by DNA-based HLA typing to more closely match potential donors. Coupled with improved methods to control graft-versus-host disease and prevent fungal and cytomegalovirus infection, remarkable progress has been made in alternative donor transplantation. For patients 50 years of age or younger, with recently diagnosed chronic myelogenous leukemia (CML) in chronic phase, 1- and 5-year survivals after HLA-A, B, DRB1 identical unrelated marrow transplantation in Seattle are 82% and 74%, respectively. These results are essentially identical to outcome in similar patients given HLA-matched sibling allografts. However, the world-wide number of alternative donor transplants for thalassemia remains limited to date: 4 unrelated and 60 HLA-nonidentical related transplants have been reported to the IBMTR since 1969 with actuarial overall survival of 75%. Using the paradigm of CML, it is likely that access to curative therapy of thalassemia will improve with optimal HLA typing and donor selection early in the course of disease.

Factors affecting risk of relapse and leukemia-free survival in HLA-identical sibling marrow transplant recipients with leukemia

Factors affecting risk of relapse and leukemia-free survival in HLA-identical sibling marrow transplant recipients with leukemia

Donor helper T-cell frequencies as predictors of acute graft-versus-host disease in bone marrow transplantation between HLA-identical siblings.

Despite the current level of sophistication of molecular typing for class I and class II alleles, a significant proportion (20-40%) of recipients of HLA-identical sibling marrow develop severe, acute graft-versus-host disease (GVHD) after bone marrow transplantation. It has been suggested that the frequency of patient-specific helper T lymphocyte precursors (HTLp) detected in the HLA-identical sibling donor correlates with the incidence and severity of acute GVHD after transplantation. This study group consisted of 42 patients who all received bone marrow from HLA-identical sibling donors from January 1990 to December 1996. Using a limiting dilution analysis, donor HTLp frequencies were determined on samples collected before transplantation. The HTLp assay used the cytotoxic T-cell line, CTLL-2, which proliferates in the presence of interleukin-2. The reliability and reproducibility of this assay was established by using cryopreserved batches of CTLL-2 cells of known sensitivity. The recipient-directed HTLp frequencies detected in the donor before transplantation were correlated with the incidence and severity of acute GVHD experienced by the recipient after transplantation. Statistical analysis revealed an extremely significant correlation between donor precursor frequencies and the development of acute GVHD in the patient after transplantation (P<0.0001). This study suggests that together with molecular typing the HTLp frequency should be considered when selecting the most suitable sibling donor for bone marrow transplantation.

FK506 (Tacrolimus) Monotherapy for Prevention of Graft-Versus-Host Disease After Histocompatible Sibling Allogeneic Bone Marrow Transplantation

FK506 (Tacrolimus) is an immunosuppressive drug that blocks the activation of antigen-specific T lymphocytes, a major component in the pathogenesis of graft-versus-host disease (GVHD). This study was designed to obtain first estimates of the safety and efficacy of FK506 monotherapy in the prevention of GVHD following HLA-identical sibling marrow transplantation. Additionally, a subset of patients was studied to define the pharmacokinetic profile of FK506. Twenty-seven adult patients with leukemia or myelodysplasia received FK506 starting the day before transplant at a dose of 0.04 mg/kg/d by continuous intravenous infusion. When clinically possible, FK506 was given orally in two divided doses starting at five times the daily intravenous dose. FK506 doses were adjusted to target a steady state or trough blood level between 10 to 30 ng/mL. These patients were followed for 6 months posttransplant. All patients had sustained marrow engraftment. Frequently noted adverse events included reversible renal dysfunction, diarrhea, fever, nausea, vomiting, and headache. Most patients required FK506 dose reductions associated with elevated serum creatinine. Two (7%) patients relapsed, one of whom died of the disease within the 6-month study period. A second patient died due to pulmonary mucor. Whole blood pharmacokinetic parameters indicated a half-life of 18.2 +/- 12.1 hours; volume of distribution of 1.67 +/- 1.02 L/kg; clearance of 71 +/- 34 mL/h/kg; and bioavailability of 32 +/- 24%. Eleven of 27 (41%) patients developed grade II to IV acute GVHD, including 10 grade II and one grade III. Six of 24 (25%) evaluable patients developed chronic GVHD. These data indicate that FK506 monotherapy has activity in preventing GVHD. Further studies of FK506 with lower doses to improve tolerability and in combination with other immunosuppressants to augment efficacy are warranted.

Marrow transplantation for Fanconi anaemia: conditioning with reduced doses of cyclophosphamide without radiation.

Nine patients with Fanconi anaemia (FA) were conditioned for HLA-identical sibling bone marrow transplant (BMT) with reduced dose of cyclophosphamide (Cy) without radiation or antithymocyte globulin (ATG). The total dose of Cy was 140 mg/kg (n = 2) or 120 mg/kg (n = 7). The median patient age was 8 years (range 4-19). Graft-versus-host disease (GVHD) prophylaxis was with methotrexate and cyclosporine (n = 8) or cyclosporine alone (n = 1). All patients had sustained engraftment and two developed grade>/= II acute GVHD. Cy toxicity included grade >/= 2 mucositis seen in all evaluable patients and haemorrhagic cystitis in two patients. The Kaplan-Meler survival estimate is 89% with a median follow-up of 285 d (range 56-528). For the purpose of comparison, this report also reviews and updates long-term follow-up data on 32 previously reported FA patients conditioned with 140-200 mg Cy/kg without radiation. The lowest dose of Cy (without radiation or ATG) after which HLA-identical sibling marrow transplant can be successfully performed in FA patients has yet to be determined, but it appears that uniform and sustained engraftment can be achieved with a Cy dose of as low as 120 mg/kg.

Five year leukaemia-free survival of 72% and 77% for early stage acute and chronic myeloid leukaemia treated by HLA-identical sibling bone marrow transplantation.

HLA-identical sibling bone marrow transplantation is an accepted treatment for patients with acute myeloid leukaemia (AML) and chronic myeloid leukaemia (CML). We have recently reported improving results in HLA-identical sibling transplant over the ten year period 1981-1990. In this report we described the outcome in patients transplanted at St Vincent's Hospital, Sydney between 1989 and 1993. To determine the leukaemia-free survival, transplant-related mortality rate, and relapse rate for patients with AML or CML given HLA-identical sibling marrow transplants between 1989 and 1993. Sixty-two patients with AML or CML received high dose busulphan/cyclophosphamide chemotherapy followed by infusion of T replete, HLA-identical sibling bone marrow. Cyclosporin/short methotrexate was utilised as prophylaxis for graft-versus-host disease, ganciclovir as prophylaxis for cytomegalovirus disease and cotrimoxazole as prophylaxis for Pneumocystis carinii pneumonia. Low dose intravenous heparin was used as prophylaxis for hepatic veno-occlusive disease. The five year disease-free survival for patients with AML transplanted in first complete remission was 72% and for those with CML transplanted in first chronic phase was 77%. The relapse rate for AML transplanted in first complete remission was 15% and for CML in first chronic phase 0%. The transplant-related mortality for AML transplanted in first complete remission was 16% and for CML transplanted in first chronic phase 23%. In contrast, the disease-free survival, relapse rate and transplant-related mortality for patients with AML transplanted outside first complete remission and for CML transplanted beyond first chronic phase was 17%, 57% and 57% respectively. The outcome for patients transplanted for early AML or early CML continues to improve and exceeds that obtainable by conventional therapy. The salvage rate is so low for patients transplanted in later stages of AML or CML that all patients less than 55 years of age with these diseases, who have a HLA-identical sibling donor, should be offered bone marrow transplantation early in their disease course.

Use of Unrelated Marrow Grafts Compensates for Reduced Graft-Versus-Leukemia Reactivity After T-Cell-Depleted Allogeneic Marrow Transplantation for Chronic Myelogenous Leukemia

The effect of donor/recipient histocompatibility on relapse in patients receiving T-cell-depleted (TCD) grafts for chronic myelogenous leukemia (CML) was evaluated. Specifically, we sought to determine whether TCD results in an attenuation of the graft-versus-leukemia (GVL) effect on recipients of unrelated marrow grafts similar to that observed in HLA-identical sibling marrow transplantations. This question was addressed by comparative analysis of the relapse rates in marrow grafts who otherwise received identical preparative regimens and graft-versus-host disease (GVHD) prophylaxis schedules (T-cell depletion with T10B9 monoclonal antibody and complement plus posttransplant cyclosporine) and by serial molecular analyses using the polymerase chain reaction (PCR) to detect the bcr/abl RNA transcript in patients transplanted with unrelated donor grafts. Patients transplanted with advanced disease (accelerated phase or blast crisis) had equally high relapse rates, regardless of whether they received HLA-identical sibling (56%;95% confidence interval [CI], 29% to 82%) or unrelated marrow grafts (8%; 95% CI, 0% to 28%) had a significantly lower incidence of relapse than did patients transplanted with HLA-identical marrow grafts (47%; 95% CI, 23% to 71%; P = .002). Because all patients were similarly treated, these data indicate that the lower relapse rate in these unrelated patients was caused by an augmented GVL effect that was most likely attributable to increased HLA disparity between donor and recipient. The probability of developing both acute and chronic GVHD was significantly increased in chronic-phase recipients of unrelated marrow grafts, suggesting that the enhanced GVL effect was at least partly GVHD-associated. The lack of such a finding in advanced disease patient receiving unrelated marrow grafts raises the possibility that clinically significant GVL effect after TCD marrow transplantation was limited and confined to patients with more indolent disease. Serial PCR analyses for the presence of the bcr/abl RNA transcript showed that the vast majority of patients transplanted in chronic phase with unrelated marrow grafts were persistently PCR-negative, indicating that the GVL effect was durable in these patients. Most of these patients were observed to become PCR negative within 1 to 2 months after transplantation, showing that early eradication of leukemia was possible with TCD marrow grafts. This study shows that the use of unrelated marrow grafts compensates for reduced GVL reactivity associated with TCD in patients transplanted for CML. Furthermore, these data indicate that, in selected patient populations with CML, TCD can be used to reduce GVHD without a commensurate compromise in the GVL effect.

Allogeneic bone marrow transplantation for lysosomal storage diseases

Patients with lysosomal storage disorders have visceral, skeletal, and neurological abnormalities and a limited life expectancy. Bone marrow transplantation has been used to correct the metabolic defects and leads to metabolic improvements in most patients However, the long-term effect of such therapy is uncertain. We analysed the data from 63 patients transplanted for lysosomal storage diseases. The transplant-related mortality was 10% if an HLA-identical sibling marrow donor was available (n=40) and 20-25% if mismatched tissue was used. Data on the effect of bone marrow transplantation on biochemical and clinical disease variables were available in 29 of the 63. 28 had a follow-up duration of 1·0-10·2 years; 1 patient died of disease progression in the first year after stable engraftment. 13 patients who had severe neurological symptoms at the time of transplantation showed disease progression. Engraftment of bone marrow in 5 patients with non-neuronopathic Gaucher's disease led to complete disappearance of symptoms. 11 patients had skeletal symptoms because of various mucopolysaccharidoses (MPSs). There was stabilisation of the skeletal lesions during the observation period of 1·4-6·4 years, but none of the patients showed significant regression of the skeletal symptoms. The visceral features (hepatosplenomegaly, cardiac hypertrophy, and upper airway obstruction) in these patients abated after transplantation. We could not evaluate the biochemical and clinical variables in 34 patients because of graft rejection, transplant-related mortality, or follow-up of less than 1 year. There were significant beneficial effects of bone marrow transplantation in patients with non-neuronopathic Gaucher's disease. Stabilisation of disease was observed in patients with MPS-I and MPS-II; this potential benefit needs to be confirmed by longer follow-up. Bone marow transplantation was not effective if severe neurological symptoms were already present at the time of transplantation.