Hemopoietic stem cell transplantation in thalassemia: a report from the European Society for Blood and Bone Marrow Transplantation Hemoglobinopathy Registry, 2000-2010.

Allogeneic hemopoietic stem cell transplantation (HSCT) is the only method currently available to cure transfusion-dependent thalassemia major that has been widely used worldwide. To verify transplantation distribution, demography, activity, policies and outcomes inside the European Group for Blood and Marrow Transplantation (EBMT), we performed a retrospective non-interventional study, extracting data from the EBMT hemoglobinopathy prospective registry database. We included 1493 consecutive patients with thalassemia major transplanted between 1 January 2000 and 31 December 2010. In total, 1359 (91%) transplants were performed on patients <18 years old, 1061 were from a human leukocyte Ag-identical sibling donor. After a median observation time of 2 years, the 2-year overall survival (OS) and event-free survival (EFS; that is, thalassemia-free survival) were 88 ± 1% and 81 ± 1%, respectively. Transplantation from a human leukocyte Ag-identical sibling offered the best results, with OS and EFS of 91 ± 1% and 83 ± 1%, respectively. No significant differences in survival were reported between countries. The threshold age for optimal transplant outcomes was around 14 years, with an OS of 90-96% and an EFS of 83-93% when transplants were performed before this age. Allogeneic HSCT for thalassemia is a curative approach that is employed internationally and produces excellent results.

The role of killer immunoglobulin-like receptor haplotypes on the outcome of unrelated donor haematopoietic SCT for thalassaemia.

Recent insight into the pathophysiology of acute GVHD after allogeneic haematopoietic SCT has led to a growing interest in the role of natural killer (NK) cells. NK cell cytotoxicity is mainly regulated by the interaction of activating and inhibitory killer immunoglobulin-like receptors (KIRs) with their respective ligands. To investigate the impact of KIRs and their ligands on haematopoietic SCT outcome, we performed a retrospective study of 78 transfusion-dependent thalassaemia patients (median age 10 years, range 1-29 years) transplanted from an unrelated donor selected using high-resolution molecular typing for both class I and II loci after a myeloablative conditioning regimen. GVHD prophylaxis consisted of CsA, short-term MTX and anti-thymocyte globulin in all patients. We found that patients transplanted from donors homozygous for KIR haplotype A had a greater risk of developing grade II-IV acute GVHD compared with those transplanted from a donor carrying at least one B haplotype (hazard ratio=4.5, 99% confidence interval=1.2-17.1, P=0.003). Our study suggests that KIR genotyping of donor and recipient pairs could contribute to the identification of patients at high risk for developing severe complications of haematopoietic SCT and thus may help with the choice of intensity of GVHD prophylaxis.

Decision-making in adult thalassemia patients undergoing unrelated bone marrow transplantation: quality of life, communication and ethical issues.

Bone marrow transplantation (BMT) represents a potentially curative treatment of thalassemia. For patients without an HLA-identical sibling donor, recourse to an unrelated donor is a practicable option but the candidates and their families are faced with a difficult decision. They can either choose to continue the supportive therapy, with no chance of definitive cure, or they accept the mortality risk of BMT in the hope of obtaining a definitive resolution of the disease. We investigated the communication strategies and the post transplantation quality of life (QoL) in 19 adult thalassemia patients surviving after an unrelated donor BMT. The patients were given two questionnaires: a questionnaire to evaluate pre-transplantation communication factors and the EORTC QLQ-C30 questionnaire to assess global QoL. All patients were satisfied with the communication modalities employed by the physicians. The global post transplantation QoL in our patient cohort was found to be good. The approach used in this study may offer a contribution to understanding the decision-making process leading to the choice of a treatment with a high mortality risk for a chronic, non-malignant disease. Finally, some ethical issues of this therapeutic approach are briefly addressed.

Unrelated donor stem cell transplantation in adult patients with thalassemia.

Allogeneic SCT remains the only potential cure for patients with thalassemia. However, most BMT candidates lack a suitable family donor and require an unrelated donor (UD). We evaluated whether BMT using UDs in high-risk adult thalassemia patients can offer a probability of cure comparable to that reported employing an HLA-compatible sibling as donor. A total of 27 adult thalassemia patients (15 males and 12 females, median age 22 years) underwent BMT from a UD selected by high-resolution HLA molecular typing. The conditioning regimen consisted of Busulphan (BU, 14 mg/kg) plus Cyclophosphamide (CY, 120 or 160 mg/kg) in 12 cases and BU (14 mg/kg), Thiotepa (10 mg/kg) and CY (120-160 mg/kg) in the remaining 15 cases. Cyclosporine-A and short-term Methotrexate were used for graft-versus-host disease (GVHD) prophylaxis. In all, 19 patients (70%) are alive and transfusion-independent after a median follow-up of 43 months (range 16-137). A total of 10 patients (37%) developed grade II-IV acute GVHD and six (27%) chronic GVHD. Eight patients (30%) died from transplant-related causes. UD-BMT can cure more than two-thirds of adult thalassemia patients, and is a particularly attractive option for patients who are not compliant with conventional treatment.

Unrelated bone marrow transplantation in thalassemia. The experience of the Italian Bone Marrow Transplant Group (GITMO).

BACKGROUND AND OBJECTIVES: Allogeneic bone marrow transplantation (BMT) is a widely accepted therapeutic approach in homozygous beta-thalassemia. However, the majority of patients do not have a genotypically identical donor within the family. This prompted us to conduct a pilot study to investigate the feasibility of matched unrelated bone marrow transplantation in thalassemia. The major drawback was the high risk of immunologic and transplant-related complications, mainly graft-versus-host disease (GvHD) and graft failure. DESIGN AND METHODS: Our aim was to reduce this risk through careful selection of donor/recipient pairs. HLA haplotypes that show a high linkage disequilibrium among their class I, class II and class III alleles are considered extended or ancestral haplotypes. RESULTS: These haplotypes are conserved and can be shared by apparently unrelated individuals. Our study shows that matching for these haplotypes significantly improves the outcome of unrelated bone marrow transplantation in thalassemia. In fact, results were comparable to those obtained in transplants using HLA-identifical family donors. INTERPRETATION AND CONCLUSIONS: Better results were obtained in patients with lesser iron overload and when the donor shared an identity for the DPB1 alleles.

Fate of chronic myeloid leukemia patients treated with allogeneic bone marrow transplantation or chemotherapy and/or interferon at a single center: long-term results.

From April 1981 to February 2000, 105 patients with chronic myeloid leukemia (CML) underwent BMT from HLA-identical related donors at a single center. Eighty-eight patients were in chronic phase (CP), 11 patients in accelerated phase and six patients in blast crisis. Ten of these patients received a second BMT (BMT2). Comparison of BMT in CP with chemotherapy and/or alpha-IFN (n=70) was also made. Patients were given cyclophosphamide (CY) and single-dose TBI (CYTBI, n=38) or busulfan (BU) and CY (BUCY, n=67). Overall 54 patients are alive and 52 of them are disease-free with a median follow-up of 11.3 (range 1.1-19.4) years. Ten-year disease-free survival (DFS) in CP patients was better after BUCY, 61% (95% CI, 47-68%) than after CYTBI, 41% (95% CI, 23-61%) (P=0.07). For 88 patients who received a transplant in CP, results were significantly improved when BMT was performed within 1 year after diagnosis (P=0.02) or at an age < or = 25 years old (P=0.01). Ten-year survival in patients who received BMT in CP was better than in patients treated with chemotherapy (56% vs 10%; P=0.0001) or alpha-IFN-based treatment (33%; P=0.09) with survival curves crossing at 4.2 years and at 4 years, respectively. The probability of DFS after BMT2 was 60% (95% CI, 26-87%). CP patients who received BMT after CYTBI had a higher probability of relapse and transplant-related mortality than patients receiving BUCY (53% and 58% vs 9% and 34%; P=0.002 and P=0.08, respectively). All but six patients are currently on no medication and have resumed all activities without any limitation. These long-term results confirm that allogeneic BMT is the only curative approach for CML patients and should be offered to all patients with a suitable donor as soon after diagnosis as possible.

Unrelated donor marrow transplantation: an update of the experience of the Italian Bone Marrow Group (GITMO).

BACKGROUND AND OBJECTIVES: Unrelated donor bone marrow transplant (UD-BMT) has become an attractive alternative source of hematopoietic cells for patients lacking a matched sibling. The aim of this paper was to report on results of the 696 UD BMTs performed in 31 Italian institutions during the first 10 years of activity of the Italian Bone Marrow Donor Registry (IBMDR). EVIDENCE AND INFORMATION SOURCES: In 1989 the Italian Bone Marrow Transplant Group (GITMO) established the IBMDR to facilitate donor search and marrow procurement for patients lacking an HLA identical sibling. By end of December 1999, 260,000 HLA-A, B typed volunteer donors had been cumulatively registered and 2,620 searches had been activated for Italian patients. At least one HLA-A, B, DRB1 matched donor was found for 54% of the patients and 696 UD BMTs were performed. In 50% of cases the donor was found in the IBMDR and in 50% in 15 other Registries. The average time from search activation to transplant was 6 months for disease other than CML. For CML it was 14 months. Actuarial 12-month transplant-related mortality (TRM) was 68% in patients grafted between 1979 and 1992 and 44% for patients grafted after 1993. Twenty-eight per cent of patients developed grade III or IV acute GvHD and 24% developed extensive chronic GvHD. The rate of disease free survival at three years was 57% for patients with 1st chronic phase CML, 37% for patients with 1st or 2nd CR ALL, 31% for AML or MDS patients 18 years of age and 54% for patients with inborn errors. PERSPECTIVES: We conclude that the IBMDR has benefited a substantial number of patients lacking a matched sibling and has facilitated the recruitment of UDs into the international donor pool. The long time required for the search is the major obstacle to the success of this programme. This suggests that early transplant and a decrease in TRM could further improve these encouraging results.

A three or more drug combination as effective therapy for moderate or severe chronic graft-versus-host disease.

We analyzed the results of a three or more drug combination as treatment for moderate or severe cGVHD developing after transplantation for thalassemia, in 45 patients with median age of 11 (range 2-26) years. Eighteen patients received a three drug regimen with cyclosporine (CsA), methylprednisolone (MP) and azathioprine (AZ) as first line therapy, 16 patients received this regimen as salvage therapy and 11 patients were given a four or five drug regimen with CsA, MP, AZ, cyclophosphamide (CY) and/or methotrexate (MTX) mainly as salvage therapy. The overall complete response (CR) rate was 77.3%, with 94% of CR in patients receiving the three drug regimen as first line, 88% in patients receiving it as salvage therapy and 36.6% in patients given the four or five drug regimen. The probability of CR in patients given the three drug regimen as first or salvage therapy or the four/five drug regimen was 89%, 53% and 30%, while the probability of survival was 89%, 65% and 58%, respectively. The incidence of treatment failure was low in our patients. Patients treated with the three drug regimen as first line therapy had less treatment-related complications than patients receiving this regimen as salvage therapy or patients given the four or five drug regimen. The main causes of treatment-related mortality (20%) were infectious complications. This retrospective study showed that a three or more drug combination is safe and effective for treatment of moderate or severe cGVHD at least in younger patients.

Hepatic iron concentration and total body iron stores in thalassemia major.

BACKGROUND AND METHODS: We tested the usefulness of measuring the hepatic iron concentration to evaluate total body iron stores in patients who had been cured of thalassemia major by bone marrow transplantation and who were undergoing phlebotomy treatment to remove excess iron. RESULTS: We began treatment with phlebotomy a mean (+/-SD) of 4.3+/-2.7 years after transplantation in 48 patients without hepatic cirrhosis. In the group of 25 patients with liver-biopsy samples that were at least 1.0 mg in dry weight, there was a significant correlation between the decrease in the hepatic iron concentration and total body iron stores (r=0.98, P<0.001). Assuming that the hepatic iron concentration is reduced to zero with complete removal of body iron stores during phlebotomy, the amount of total body iron stores (in milligrams per kilogram of body weight) is equivalent to 10.6 times the hepatic iron concentration (in milligrams per gram of liver, dry weight). With the use of this equation, we could reliably estimate total body iron stores as high as 250 mg per kilogram of body weight, with a standard error of less than 7.9. CONCLUSIONS: The hepatic iron concentration is a reliable indicator of total body iron stores in patients with thalassemia major. In patients with transfusion-related iron overload, repeated determinations of the hepatic iron concentration can provide a quantitative means of measuring the long-term iron balance.

Bone marrow transplantation from alternative donors for thalassemia: HLA-phenotypically identical relative and HLA-nonidentical sibling or parent transplants.

Twenty-nine patients with thalassemia and a median age of 6 years (range 1.1-33 years) were given a BMT from an alternative donor. Six of the 29 donors were HLA-phenotypically identical and two were mismatched relatives, 13 were mismatched siblings and eight were mismatched parents. Six patients received no antigen (relatives), 15 patients one antigen, five patients two antigen and three patients three antigen disparate grafts. Twenty-three patients were in class 2 or class 3, whereas six patients were in class 1. Thirteen patients were given BUCY, nine patients BUCY plus ALG, six patients BUCY plus TBI or TLI and one patient BUCY with prior cytoreductive-immunosuppressive treatment as conditioning. As GVHD prophylaxis four patients received MTX, 22 CsA + MTX + methylprednisolone (MP) and three patients CsA + MP. Thirteen of 29 patients (44.8%) had sustained engraftment. The probability of graft failure or rejection was 55%. There were no significant differences between antigen disparities and graft failure. The incidence of grade II-IV acute GVHD was 47.3% and chronic GVHD was 37.5%. The incidence of acute GVHD was higher in patients receiving one or two antigen disparate in the GVHD direction grafts (vs no antigen) (P EQ 0.04; odds ratio 10.8; 95% CI 1.5-115). The probability of overall and event-free survival was 65% and 21%, respectively, with median follow-up of 7.5 years (range 0.6-17 years) for surviving patients. The degree of HLA disparity between patient and donor did not have a significant effect on survival. The incidence of nonhematologic toxicity was low. Transplant-related mortality was 34%. GVHD (acute or chronic) was a major contributing cause of death (50%) followed by infections (30%). We conclude that at present, due to high graft failure and GVHD rates, BMT from alternative donors should be restricted to patients who have poor life expectancies because they cannot receive adequate conventional treatment or because of alloimmunization to minor blood antigens.

Trichosporon beigelii: a life-threatening pathogen in immunocompromised hosts.

Patients undergoing bone marrow transplantation are profoundly immunosuppressed as a result of their intensive myeloablative chemotherapy and are at high risk for opportunistic fungal infections mainly caused by Candida spp and Aspergillus spp. Trichosporon beigelii (T beigelii) has emerged as a life-threatening opportunistic pathogen in granulocytopenic and immunocompromised hosts and there is a marked increase in cases reported in the literature. Response to antifungal agents is poor, mortality is high and immunological recovery is the most important factor for a favorable outcome in patients with trichosporonosis. We present three cases of T. beigelii infection in patients undergoing allogeneic bone marrow transplantation in our center and we review cases described in the literature.

Unrelated donor marrow transplantation: an update of the experience of the Italian Bone Marrow Transplant Group (GITMO).

Unrelated donor bone marrow transplant (UD-BMT) has become an attractive alternative source of hematopoietic cells for patients lacking a matched sibling. The aim of this paper was to report on results of the 696 UD BMTs performed in 31 Italian institutions during the first 10 years of activity of the Italian Bone Marrow Donor Registry (IBMDR). In 1989 the Italian Bone Marrow Transplant Group (GITMO) established the IBMDR to facilitate donor search and marrow procurement for patients lacking an HLA identical sibling. By end of December 1999, 260,000 HLA-A, B typed volunteer donors had been cumulatively registered and 2,620 searches had been activated for Italian patients. At least one HLA-A, B, DRB1 matched donor was found for 54% of the patients and 696 UD BMTs were performed. In 50% of cases the donor was found in the IBMDR and in 50% in 15 other Registries. The average time from search activation to transplant was 6 months for disease other than CML. For CML it was 14 months. Actuarial 12-month transplant-related mortality (TRM) was 68% in patients grafted between 1979 and 1992 and 44% for patients grafted after 1993. Twenty-eight per cent of patients developed grade III or IV acute GvHD and 24% developed extensive chronic GvHD. The rate of disease free survival at three years was 57% for patients with 1st chronic phase CML, 37% for patients with 1st or 2nd CR ALL, 31% for AML or MDS patients < or = 18 years of age and 54% for patients with inborn errors. We conclude that the IBMDR has benefited a substantial number of patients lacking a matched sibling and has facilitated the recruitment of UDs into the international donor pool. The long time required for the search is the major obstacle to the success of this programme. This suggests that early transplant and a decrease in TRM could further improve these encouraging results.

Bone marrow transplantation for beta-thalassemia.

Bone marrow transplantation in thalassemia represents the only form of radical cure of this disease. Patients younger than 17 years are divided into three classes of risk according to the presence or absence of portal fibrosis, hepatomegaly, and history of adequate chelation treatment. Patients older than 16 years are categorized as adult thalassemics. Survival and event-free survival are 93% and 91% for Class 1, 87% and 83% for Class 2, and 79% and 58% for Class 3, respectively. Adult patient survival is 66% and event-free survival is 62%.

Bone marrow transplantation for transfused patients with severe aplastic anemia using cyclophosphamide and total lymphoid irradiation as conditioning therapy: long-term follow-up from a single center.

In transfused patients with aplastic anemia, incidence of graft rejection remains significant. Seventeen transfused patients with severe aplastic anemia received BMT from HLA-identical sibling donors after conditioning with cyclophosphamide (CY, 50 mg/kg/day for 4 days) plus total lymphoid irradiation (TLI, 750 cGy in a single dose). For graft-versus-host disease (GVHD) prophylaxis one patient received methotrexate, five patients received CsA and 11 received CsA in association with methylprednisolone. All patients had sustained engraftment. The actuarial survival of patients was 76% with a median follow-up for surviving patients of 11 years (range 0.3-14.5 years). The incidence of grade II-III acute GVHD was 24%, and chronic GVHD 35%. Median Karnofsky score of surviving patients is 100 (range 90-100). Only one patient developed interstitial pneumonia. None of the patients has developed a malignancy after BMT. The role of limited field irradiation in development of malignant neoplasms after BMT for aplastic anemia is discussed. We conclude that a conditioning regimen using CY + TLI in sensitized aplastic anemia patients results in a high survival rate on long-term follow-up.

Bone marrow transplantation in adult thalassemic patients.

One hundred seven adult patients with thalassemia aged from 17 through 35 years and transplanted from HLA-identical siblings between November 1988 and September 1996 were evaluated on December 31, 1997. The outcome experience of 20 consecutive patients transplanted between November 13, 1988 and January 10, 1991 and reported in September 1992 is updated after 5 additional years. The experience on 87 patients transplanted between May 1991 and September 1996 is described and evaluated as of the end of December 1997. Of 107 patients, 69 survive between 1.5 and 9 years after transplantation. Sixty-six of these patients do not have thalassemia and are identified as ex-thalassemic after bone marrow transplantation. The youngest survivor is 20 years old, 6 are older than 30 years, and the oldest is 37 years of age. Patients with chronic active hepatitis at the time of transplant were significantly more likely to die than patients without (P =.05; relative risk, 2.05). Marrow transplantation is a valid treatment option for older patients with thalassemia who have suitable donors and show deterioration with conventional therapy.

Second marrow transplants for graft failure in patients with thalassemia.

Thirty-two thalassemic patients with a median age of 7.7 years (range 3.4-26 years) were given a second HLA-identical related marrow transplant (BMT2) for graft failure. Four patients were in class 1 and 28 patients in classes 2 and 3. Twenty-one patients had full thalassemia recurrence (first group) and 11 patients had aplastic marrows (second group) either with or without residual donor marrow cells after the first BMT (BMT1). As conditioning regimen for BMT2 all but five patients received BUCY or CY in association with total lymphoid irradiation (TLI) and/or anti-lymphocyte globulin (ALG), whereas nine patients received a new preparative regimen with hydroxyurea, azathioprine, fludarabine before conditioning with BUCY. Twenty one of 31 evaluable patients (67.7%) had initial, and 16 (51.6%) had sustained engraftment. Ten patients (32.3%) failed to engraft. Overall and event-free survival for the entire group of patients were 49% and 33%, respectively, with a median follow-up of 4 years (range 0.6-14 years) for surviving patients. Event-free survival was higher in the second group of patients compared with the first group (41% vs 29%). The second group of patients appeared to have less graft failure compared with the first group (30% vs 63%; P = 0.1). Transplant-related mortality was 28%. A linear stepwise regression analysis revealed that occurrence of graft failure within 60 days after BMT1 (P = 0.04) and absence of residual donor marrow cells (P = 0.009) predicted for graft failure following BMT2, whereas the occurrence of graft failure after 60 days (P = 0.03) had a positive influence on survival following BMT2. The incidence of grade >/=2 acute GVHD was low (14%). Eight of nine patients who received the new preparative regimen are alive, four without thalassemia. This study shows that BMT2 can be an effective therapy for a proportion of patients with poor survival expectancies despite conventional treatment.

Bone marrow transplantation in thalassemia. The experience of Pesaro.

Early trials of allogenic bone marrow transplantation (BMT) for homozygous beta thalassemia and the analyses of results of transplantation in patients under 17 years of age have allowed us to identify 3 classes of risk using the criteria of degree of hepatomegaly, the degree of portal fibrosis, and the quality of the chelation treatment given before the transplant. Patients for whom all 3 criteria were adverse constituted Class 3, patients with none of the adverse criteria constituted Class 1, and patients with 1 or various associations of 2 of the adverse criteria formed Class 2. Most patients older than 16 years have disease characteristics that place them in Class 3, with very few in Class 2. For all the patients with an HLA identical donor we are actually using 2 protocols to which the patient is assigned on the basis of the Class he belongs to at the time of BMT and independently from the age of the patient. For 104 patients in Class 1 and for 262 patients in Class 2 prepared for the transplant with busulfan 14 mg/kg, cyclophosphamide 200 mg/kg and cyclosporine alone, the probabilities of survival and of event-free survival are 95% and 90% for Class 1 and 87% and 84% for Class 2. For 33 Class 3 patients prepared for the transplant with busulfan 14 mg/kg, cyclophosphamide reduced to 160 mg/kg, cyclosporine, and "short" methotrexate, the probabilities of survival and event-free survival are 89% and 64%. For 57 adult patients (17 to 35 years), who underwent the transplant after preparation with the same protocol used for Class 3, the probabilities of survival and of event-free survival are 70% and 68%, respectively. BMT remains the only form of radical treatment for thalassemia in those patients with an HLA-identical donor.

Treatment of iron overload in the "ex-thalassemic". Report from the phlebotomy program.

After successful marrow transplantation (BMT) iron overload remains an important cause of morbidity in Thalassemia. After BMT, patients have normal erythropoiesis capable of producing a hyperplastic response to phlebotomy so that this procedure can be contemplated as a method of mobilizing iron from overloaded tissues. Forty-one patients (mean age 16 +/- 2.9 years) with prolonged follow-up (range 2-7 years) after BMT were submitted to a moderate intensity phlebotomy program (6 ml/kg blood withdrawal at 14-day intervals) to reduce iron overload. Values are expressed as mean +/- SD or as median with a range (25th-75th percentile). Serum ferritin decreased from 2,587 (2,129-4,817) to 280 (132-920) micrograms/l (p < 0.0001), total transferrin increased from 2.34 +/- 0.37 to 2.9 +/- 0.66 g/l (p = 0.0001), transferrin saturation decreased from 90% +/- 14% to 39% +/- 34% (p < 0.0001). Liver iron concentration evaluated on liver biopsy specimens decreased from 20.8 (15.5-28.1) to 3 (0.9-14.6) mg/g dry weight (p < 0.0001). Alanine amino-transaminase from 5.2 +/- 3.4 to 1.6 +/- 1.2 (p < 0.0001) times the upper level of normality. The histological grading for chronic hepatitis (Histology Activity Index) decreased from 4.2 +/- 2.4 to 2.3 +/- 1.8 (p < 0.0001). Phlebotomy is a safe, efficient, and widely applicable method to decrease iron overload in "ex-thalassemic."

Unrelated donor marrow transplantation for inborn errors.

From December 1989 to December 1997 40 children aged 1 year to 19 years with inborn errors other than severe combined immunodeficiencies underwent unrelated donor (UD) bone marrow transplantation (BMT) in one of 10 institutions of the Italian Bone Marrow Transplant Group participating in this program. The diseases leading to BMT included Fanconi Anemia (10), Thalassemia (8), Wiskott Aldrich syndrome (5), haemophagocytic lymphohystiocytosis (6), osteopetrosis (3), storage diseases (6), Chediak Higashi syndrome (1), Schwachman syndrome (1). Thirty-three pairs were A, B, DRB1 matched. Three pairs were one antigen mismatched and one pair was two antigens mismatched. The remaining three pairs lacked information on molecular biology. Twelve children underwent a preparative regimen including radiotherapy. The remaining 28 children were conditioned with a chemotherapy regimen which included Busulfan. GvHD disease prophylaxis included CSA and MTX alone (9) or associated with ALG (17) or in vivo Campath 1G (12). The remaining two children received CSA alone. Thirty-five children showed donor engraftment; three children with thalassemia and one with osteopetrosis failed to engraft. Five children developed secondary graft failure. Actuarial 5 year disease-free survival was 62%; grade III-IV acute GvHD developed in seven of 38 evaluable children (18%); chronic GvHD developed in seven of 27 evaluable children (26%). We confirm that Wiskott Aldrich syndrome, HLH, and osteopetrosis represent an absolute indication for UD-BMT. Prognosis of UD-BMT for FA could improve in children grafted in an early phase, but a better preparative regimen has to be identified. UD-BMT in thalassemia is acceptable only in a restricted subset of patients selected for poor compliance to therapy.