Bone marrow transplantation for patients with acquired severe aplastic anemia using cyclophosphamide and antithymocyte globulin: the experience from a single center

Between 1998 and 2001, 31 (24 male, 7 female) patients with severe aplastic anemia (SAA) and a median age of 19 years (range, 4-39 years) received an allogeneic bone marrow transplantation. Marrow donors were genotypically HLA-identical siblings in 30 cases and a monozygous twin in one case. The median time from diagnosis to bone marrow transplantation was 1 month (range, 0.5-5 months). Conditioning regimen consisted of cyclophosphamide (CY) combined with antithymocyte globulin (ATG), in all patients. For graft-versus-host disease (GvHD) prophylaxis, all patients received methotrexate and cyclosporin. A total of 84% of patients had sustained grafts, whereas 16% rejected grafts between 3 and 20 months after transplantation. Of the five rejecting patients, three are alive with successful second engraftments and two died from infections. Acute grade II-IV GvHD was seen in only 11% of patients. A limited chronic GvHD was seen in one patient. With a median follow-up of 18 months (range, 5-42 months), survival rate was 86% and Karnofsky score was at least 90%. This study confirms the high success rate of the CY/ATG regimen in SAA allografted from an HLA-identical sibling. Early and late graft failure remains a problem and may require modification of this regimen.     

Cyclophosphamide/antithymocyte globulin conditioning of patients with severe aplastic anemia for marrow transplantation from HLA-matched siblings: Preliminary results

Many approaches have been taken to reducing the rate of graft failure and the incidence of graft-versus-host disease (GVHD) in bone marrow transplantation (BMT) of patients with severe aplastic anemia (SAA). The combination of cyclophosphamide with irradiation has had unequivocal success in reconstituting a sustained engraftment, but this procedure has severe associated risks such as second malignancies. Recently, cyclophosphamide (CYC) plus antithymocyte globulin (ATG) has been shown to be an effective alternative to irradiation-based programs in retransplants. Based on these experiences, the current clinical trial was started to prepare patients suffering from SAA for marrow transplantation from HLA-identical siblings with ATG plus CYC. Nine patients have been enrolled into the study so far. They received a total dose of 200 mg/kg CYC and concomitantly 120 mg/kg or 90 mg/kg ATG, followed by cyclosporine plus methotrexate as post-transplantation GVHD prophylaxis. Eight of nine patients survived without any transplant-associated complications; i.e., they had a documented stable engraftment without rejection and without acute or chronic GVHD. One patient died due to anAsper-gillus sepsis prior to a definite engraftment. Although our data are preliminary because of the small number of patients enrolled and a follow-up of only 30 months, CYC plus ATG appears to be an effective preparative regimen for BMT in patients with SAA, resulting in a favorable outcome.     

Fludarabine, low-dose busulfan and antithymocyte globulin as conditioning for Fanconi anemia patients receiving bone marrow transplantation from HLA-compatible related donors

Allogeneic hematopoietic stem cell transplantation (SCT) from unaffected donors remains the only modality for the correction of hematological abnormalities in Fanconi anemia (FA) patients. We performed four HLA-matched related donor SCT using a novel irradiation and cyclophosphamide-free conditioning regimen. The protocol included fludarabine 150 mg/m(2), busulfan 4 mg/kg, and antithymocyte globulin 90 mg/kg. Graft-versus-host disease (GVHD) prophylaxis was cyclosporin A, MTX, and daclizumab. The engraftment and occurrence of full stable donor hemopoiesis was rapid in all cases with minimal short-term toxic complications. There were no infections or febrile episodes during the inpatient phase. Three patients developed acute GVHD grade I-II involving gut and skin and one patient progressed to extensive chronic GVHD. The preparative conditioning regimen is safe and associated with low organ toxicity and effective immunosupression for the stable engraftment in FA patients undergoing SCT with matched related donors.     

Stem cell transplantation for patients with Fanconi anemia with low-dose cyclophosphamide and antithymocyte globulins without the use of radiation therapy

In all, 22 patients with confirmed Fanconi anemia (FA) underwent stem cell transplantation (SCT) from HLA-matched, related donors at KFSHRC. Median age at SCT was 7.6 years (range, 2.5-14.6 years). Conditioning regimen consisted of cyclophosphamide (CY) 15 mg/kg/day intravenously (i.v.) for 4 consecutive days, in addition to equine antithymocyte globulins (ATG) given i.v. at 40 mg/kg/day for four doses pre-SCT. No radiation therapy was given. For graft-versus-host disease prophylaxis, we used cyclosporin at the standard doses; ATG was added at 20 mg/kg/dose i.v. on days 2, 4, 6, 8, 10, and 12 post-SCT (total of six doses). All patients engrafted and are alive and transfusion independent with a median follow-up time of 20.2 months (range, 3.3-59 months). One patient however developed a decrease in her WBC and platelet count. Her work-up revealed slightly hypocellular bone marrow, and a series of chimerism studies over 1 year confirmed that she has stable mixed chimerism; she remains transfusion independent. We conclude that low-dose CY without radiation therapy can be used satisfactorily in the conditioning of patients with FA undergoing related SCT.     

Unrelated bone marrow transplantation in two severe aplastic anemia patients preconditioned with a regimen of cyclophosphamide, antithymocyte globulin, and total body irradiation

We report our experiences with HLA-matched unrelated bonemarrow transplantation combining a preconditioning regimen of cyclophosphamide, antithymocyte globulin (ATG), and total body irradiation for two patients with severe aplastic anemia (SAA) who had already undergone repeated blood transfusions. Short-term methotrexate and cyclosporine were administered for graft-versus-host disease (GVHD) prophylaxis. Both patients achieved rapid engraftment within 3 weeks, furthermore, neither acute nor chronic GVHD developed. Our conditioning regimen appeared to be well-suited for unrelated bone marrow transplantation in heavily transfused SAA patients. However, both patients experienced bouts of fever about 20-30 and 40-50 days after transplantation, and it was difficult to differentiate whether they were affected by acute GVHD, cytomegalovirus (CMV) infections, or serum sickness. Because weakly positive CMV antigenemia was detected, both patients were given ganciclovir. Although their fever did not respond initially, it gradually subsided following the combined administration of prednisolone. These outcomes suggest it is essential that attention be devoted to the potential for serum sickness and the high risk of herpes virus infections, particularly by CMV, following the use of intensive preconditioning regimens that include ATG.     

Bone marrow transplantation for Fanconi anemia using low-dose cyclophosphamide/thoracoabdominal irradiation as conditioning regimen: chimerism study by the polymerase chain reaction

Since 1976, patients grafted at the Hopital Saint-Louis for Fanconi anemia (FA) without evidence of leukemic transformation have been given a uniform conditioning regimen that consisted of low-dose cyclophosphamide (Cy) and thoracoabdominal irradiation (TAI). The use of low-dose Cy raised the question of whether it is sufficient for the establishment of a complete hematopoietic chimerism in all patients. We therefore initiated a study of chimerism early during hematopoietic reconstitution after bone marrow transplantation (BMT) and thereafter in transplanted FA patients. Minisatellite probes were used after DNA amplification by the polymerase chain reaction (PCR). From July 1989 to October 1992, 24 consecutive patients underwent BMT for FA, 19 of whom were assessable for chimerism. Our results using this sensitive technique showed that, among these 19 patients, all but one successfully engrafted. Engraftment was complete early after BMT in 12. The persistence of a small proportion of recipient's cells was detected in six. This partial hematopoietic chimerism was demonstrated to be only transient in at least five of the six patients. The one patient who failed to engraft showed a recipient-type profile for circulating cells early posttransplantation, indicating autologous bone marrow recovery. A second graft in this patient was also rejected. For both transplantations, the patient was grafted from a matched, unrelated donor. Therefore, 17 of 17 patients successfully grafted and with complete follow up data presented complete hematopoietic chimerism, within the sensitivity limit of the method used. In conclusion, lowering the Cy dose in the conditioning regimen of patients with FA could still allow complete engraftment to occur, at least in patients with an identical sibling donor.     

Long-term follow-up of allogeneic stem cell transplantation in patients with severe aplastic anemia after conditioning with cyclophosphamide plus antithymocyte globulin

We investigated the efficacy of an antithymocyte globulin/cyclophosphamide preparative regimen prior to allogeneic stem cell transplantation from HLA-identical siblings in patients with severe aplastic anemia. Since 1990, 21 patients, 6 males and 15 females, with a median age of 25 years (range: 7-43) have been enrolled in the protocol consisting of 200 mg/kg cyclophosphamide and 90-120 mg/kg antithymocyte globulin (ATG, rabbit, Fresenius, Bad Homburg, Germany). For further graft-versus-host disease (GVHD) prophylaxis all patients received cyclosporin A and a short course of methotrexate (MTX). Only one patient had a primary graft failure (5%). All other patients engrafted with a leukocyte count >1.0 x 10(9)/l and a platelet count >20 x 10(9)/l after a median of 19 (range: 11-28) and 26 days (range: 13-67), respectively. No late graft failure or relapse was observed. Two patients experienced mild acute GVHD grade I (10%), and one patient developed grade II GVHD (5%). No severe grade III/IV GVHD was observed; 17% of the patients developed limited chronic GVHD. The treatment-related mortality was 14% and mainly due to fungal infection. After a median follow-up of 70 months (range: 2-139), the estimated overall and event-free survival at 10 years for all patients is 86% (95% confidence interval: 70-100%). We conclude that ATG plus cyclophosphamide is an effective conditioning regimen in patients with aplastic anemia undergoing stem cell transplantation with a low treatment-related mortality, resulting in an excellent outcome.     

Bone marrow transplantation in Fanconi anemia using matched sibling donors

Eighteen patients with Fanconi anemia (FA) with evidence of bone marrow (BM) aplasia underwent allogenic BM transplants (BMT) from matched sibling donors (MSD). Median age at BMT was 7.6 years. Conditioning consisted of low-dose cyclophosphamide (CY; 5 mg/kg x 4 days) and thoracoabdominal irradiation (TAI; 400 cGy). Graft-versus-host disease (GVHD) prophylaxis included cyclosporin A and prednisone. In addition antithymocyte globulin (ATG) was administered in the pretransplant period to promote engraftment and in the posttransplant period for additional GVHD prophylaxis. Engraftment occurred rapidly (median, 12 days for an absolute neutrophil count > or = 0.5 x 10(9)/L; median, 22 days for platelet count > or = 50 x 10(9)/L). Seventeen patients have sustained engraftment and are transfusion-independent, with Lansky scores of 100% at median follow-up of 27 months. One patient developed graft failure 4 months after initial engraftment and required a second BM infusion. None of the patients developed acute GVHD; 3 patients (16%) developed chronic GVHD. BMT is a feasible option for FA patients having an MSD and should be performed at a young age and early in the course of the disease, before the development of complications. We believe the addition of ATG to the transplant regimen of low-dose CY, TAI, and cyclosporin was responsible for improvement in the survival of FA patients undergoing BMT. The regimen was well tolerated and was associated with a low incidence of complications including GVHD.     

Long-term follow up after allogeneic stem cell transplantation in patients with severe aplastic anemia after cyclophosphamide plus antithymocyte globulin conditioning

Background

Due to increased rates of secondary solid organ cancer in patients with severe aplastic anemia who received an irradiation-based conditioning regimen, we decided some years ago to use the combination of cyclophosphamide and antithymocyte globulin. We report the long-term follow up of patients who underwent hematopoietic stem cell transplantation from an HLA-matched sibling donor after this conditioning regimen.

Design and Methods

We analyzed 61 consecutive patients transplanted from June 1991 to February 2010, following conditioning with cyclophosphamide (200 mg/kg) and antithymocyte globulin (2.5 mg/kg/day × 5 days).

Results

Median age was 21 years (range 4–43); 41 of the 61 patients were adults. Median duration of the disease before hematopoietic stem cell transplantation was 93 days. All but 2 patients received bone marrow as the source of stem cells and all but 2 engrafted. Cumulative incidence of acute grade II–IV graft-versus-host disease was 23% (95%CI 13–34) and 18 developed chronic graft-versus-host disease (cumulative incidence 32% at 72 months, 95% CI 20–46). In multivariate analysis, a higher number of infused CD3 cells was associated with an increased risk of developing chronic graft-versus-host disease (P=0.017). With a median follow up of 73 months (range 8–233), the estimated 6-year overall survival was 87% (95% CI 78–97). At 72 months, the cumulative incidence of avascular necrosis was 21% and 12 patients presented with endocrine dysfunction (cumulative incidence of 19%). Only one patient developed a secondary malignancy (Hodgkin’s lymphoma) during follow up.

Conclusions

Cyclophosphamide and antithymocyte globulin is an effective conditioning regimen for patients with severe aplastic anemia and is associated with low treatment-related mortality. Long-term complications include avascular necrosis and endocrine dysfunction.     

Long-term outcome of aplastic anemia in adults treated with antithymocyte globulin: comparison with bone marrow transplantation

The outcome of 155 adult aplastic anemia (AA) patients treated with antithymocyte globulin (ATG, Upjohn, Kalamazoo, MI) at University of California, Los Angeles from 1977 to 1988 was evaluated. The median survival of the 146 patients who did not undergo bone marrow transplantation was 5.6 years, with 49% +/- 4% surviving more than 6 years. The most important predictor of survival was positive response to ATG (P < 0.001), which was observed in 48% of patients. Among pretreatment variables, disease severity was the best predictor of survival. Patients with moderate AA (MAA) had significantly better survival than those with severe (SAA) or very severe (VSAA) disease (P = 0.04). The 6-year actuarial survival rates of the three groups were 71% +/- 9%, 48% +/- 7% and 38% +/- 7%, respectively. Cox regression analysis found disease severity to be the only pretreatment variable significantly associated with survival (P = .02). Patient age, sex, disease etiology, concurrent treatment with androgens, or duration of ATG therapy were not associated with differences in survival or response to ATG. Late clonal hematologic complications (ie, myelodysplasia, acute myelogenous leukemia) were observed in 5 of the 77 patients followed for more than 2 years after ATG treatment. In addition, one case of non-Hodgkin's lymphoma and three solid tumors occurred in the ATG-treated patients. The survival of 56 ATG-treated patients with SAA or VSAA between the ages of 16 and 43 did not differ significantly from that of 55 adult AA patients who underwent bone marrow transplant (BMT) during the same time period (P = 0.6). However, 6-year survival rates improved from 43% for patients transplanted before 1984, to 72% for those who underwent BMT between 1984 and 1989. In contrast, there was no difference in the survival rates of patients treated with ATG during these two time periods (46% v 45%, respectively). The results suggest a superior long-term outcome for adult patients with SAA treated with BMT rather than with ATG alone, using current protocols.     

Cyclophosphamide combined with antithymocyte globulin in preparation for allogeneic marrow transplants in patients with aplastic anemia

Graft rejection has been a problem after marrow grafts for patients with aplastic anemia who were conditioned with cyclophosphamide (CY). Rejection lessened when patients were given the marrow donor's peripheral blood buffy-coat cells in addition to the marrow, but this result was achieved at the price of more chronic graft-versus-host disease (GVHD). Results with second transplants suggested that CY alternating with antithymocyte globulin (ATG) was more immunosuppressive than CY alone. Therefore, the current study explored CY and ATG without buffy-coat cell transfusions in 39 patients with aplastic anemia given marrow transplants from HLA-identical family members (siblings in 38 cases, father in 1 case). We hoped both to minimize the risks of graft rejection and of chronic GVHD and to improve survival. Patients were 2 to 52 years of age (median, 24.5); 87% had received previous transfusions, and 41% had therapy with immunosuppressive agents before transplant. They were administered four daily doses of CY (total, 200 mg/kg) alternating with three doses of ATG (total, 90 mg/kg) followed by an HLA-identical marrow graft. Methotrexate and cyclosporine were administered to prevent GVHD. Two patients rejected their grafts (5%), and both were successfully retransplanted. Acute (grade 2 or 3) GVHD occurred in 15% and chronic GVHD in 34% of patients. The actuarial survival rate at 3 years was 92%, which compares favorably to the 72% survival rate in 39 historical patients who were matched with current patients for age and risk factors for rejection and GVHD. CY/ATG is a well-tolerated and effective conditioning program for marrow grafting in aplastic anemia that, when combined with GVHD prevention by methotrexate/cyclosporine, results in excellent survival.     

Allogeneic stem cell transplantation in patients with Fanconi's anemia and myelodysplasia or leukemia utilizing low-dose cyclophosphamide and total body irradiation

Five patients with confirmed Fanconi's anemia (FA) and myelodysplasia and/or leukemia underwent stem cell transplantation (SCT) from related donors at KFSHRC. The median age at SCT was 12.6 year (range, 6.2-15 years). Conditioning regimen consisted of cyclophosphamide (CY) 5 mg/kg/day i.v. for 4 days, total body irradiation (TBI) 450 cGy in a single dose. Graft-versus-host disease (GVHD) prophylaxis was with cyclosporine and antithymocyte globulins (ATG). The median time to engraftment (defined as ANC>/=0.5 x 10(9)/l) was 16 days (range, 12-26 days). The median time to a self-sustaining platelet count of >/=20 x 10(9)/l was 27 days (range, 12-40 days). All patients engrafted. Two patients developed acute GVHD; one of the gut (grade 3) and the other of the skin (grade 1), and one patient developed chronic GVHD of the liver. Four are alive and well with no evidence of the disease; one patient died of bacterial sepsis after controlling her GVHD and clearing her pulmonary aspergillosis and CMV infection. We conclude that the use of low-dose CY plus TBI in patients with FA and MDS/AML undergoing SCT is adequate; the regimen is well tolerated and may be curative for such patients.     

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.     

Second marrow transplants in patients with aplastic anemia rejecting the first graft: use of a conditioning regimen including cyclophosphamide and antithymocyte globulin

Sixteen (11%) of 146 consecutive patients with severe aplastic anemia prepared for engraftment with cyclophosphamide (200 mg/kg) rejected marrow grafts from their HLA-identical siblings. They were given a second marrow transplant from either the same (n = 13) or a second (n = 3) HLA-identical sibling between 23 and 743 (median 86) days after the first transplant. The preparation for the second transplant included cyclophosphamide, 50 mg/kg, on each of four successive days. Twelve hours after each of the first three doses of cyclophosphamide, antithymocyte globulin, 30 mg/kg/dose, was infused. One of the 16 patients died from infection too early after the second transplant to be evaluated, two had failure of engraftment and died with infection, one rejected the second graft and is surviving almost 5 years later with full autologous marrow recovery, and 12 had successful and sustained second grafts. Of these 12, six are surviving between 11 months and 7 3/4 years. Four of the six have no graft-v-host disease (GVHD), while two have chronic GVHD requiring treatment. Five have Karnofsky scores of 100% and one of 90%. Six of the 12 patients with sustained grafts died between 63 days and 38 months after transplantation, four with infections (related in two patients to chronic GVHD), one with acute GVHD, and one with hemorrhage. The average interval from first to second transplant was 308 days during the past five years, compared to 61 days in earlier patients. Five of seven recent patients are surviving, compared to two of nine earlier patients. In conclusion, successful second transplants after cyclophosphamide and antithymocyte globulin are possible in most patients with aplastic anemia who have rejected their first marrow grafts; however, mortality remains high, with only 40% of the patients becoming long-term survivors.     

Bone marrow transplantation for patients with Fanconi anemia: reduced doses of cyclophosphamide without irradiation as conditioning.

Fanconi anemia (FA), a rare autosomal recessive disease, frequently evolves to bone marrow failure and acute myeloid leukemia, and BMT is the treatment of choice for patients with FA. However, their exquisite hypersensitivity to DNA cross-linking agents is associated with severe complications and several investigators have been looking for the ideal preparatory regimen. We have been involved in a program of progressively decreasing doses of cyclophosphamide (CY) as conditioning therapy, in an attempt to identify the lowest dose of CY capable of maintaining the graft with minimum complications. Here, we describe our experience of allogeneic BMT offered to 16 patients with FA and an HLA-compatible sibling donor, conditioned with 100 mg/kg of CY. The actuarial survival is 88% at approximately 37 months. Mucositis >/= grade II was the most common complication (94%), followed by bacteremias (38%). Veno-occlusive disease and hemorrhagic cystitis did not occur. Sustained engraftment was obtained in 94% of patients, and acute and chronic GVHD was diagnosed in 13% and 7%, respectively. The lowest dose of CY for transplant in FA patients is yet to be determined, but further reductions seem possible.     

Bone marrow transplantation in 107 patients with severe aplastic anemia using cyclophosphamide and thoraco-abdominal irradiation for conditioning: long-term follow-up

Since 1980, 107 consecutive patients (pts) underwent bone marrow transplantation (BMT) for nonconstitutional severe aplastic anemia (SAA) at our institution. All received conditioning with Cytoxan (150 mg/kg) and thoraco-abdominal irradiation (6 Gy) from an HLA-identical sibling donor. Mean age was 19 years (5 to 46 years). Forty-nine pts had less than 0.2 x 10(9)/L PMN and 53 failed to respond to previous immunosuppressive therapy before BMT. Graft-versus-host disease (GVHD) prophylaxis consisted of methotrexate (22 pts), cyclosporine (52 pts), or both (33 pts). With a median follow-up of 45 months (12 to 120 months), overall actuarial survival was 68% (confidence interval 95%:9.7). Of 16 factors tested, five were shown to adversely influence survival by multivariate analysis: grade greater than or equal to 2 acute GVHD (relative risk [RR]: 5.5), prior immunosuppressive therapy (RR: 3.5), female as donor (RR: 2.4), nonidiopathic SAA (RR: 2), and more than 0.2 x 10(9)/L PMN AA (RR: 2). Because acute GVHD was the most potent factor for survival, we analysed risk factors for acute GVHD. By multivariate analysis, 2 of 14 factors tested were independent: male as recipient (RR: 3) and previous alloimmunization of the donor (RR: 4.3). On long-term follow-up, chronic GVHD was observed in 49 pts of 89 surviving more than 100 days (55%). Multivariate analysis showed that infection before transplant (RR: 1.3) and previous history of acute GVHD (RR: 1.8) were associated with an increased risk of chronic GVHD.     

Addition of low-dose busulfan to cyclophosphamide in aplastic anemia patients prior to allogeneic bone marrow transplantation to reduce rejection

Busulfan was added at the dose of 4 mg/kg to 200 mg/kg cyclophosphamide in 81 patients (3-53 years, median 24) with aplastic anemia to reduce graft rejection. Graft-versus-host disease (GVHD) prophylaxis comprised cyclosporine-methotrexate. The number of prior transfusions was 0-276 (median 26), and 48% had received prior immunosuppressive therapy. Two patients experienced primary graft failure, and 10 secondary rejection at 28-1001 days (median 317 days). The cumulative incidence of rejection was 22%; for heavily transfused patients (>/=50 U) it was 43% compared to 16% for the rest (P=0.06). Overall survival rate at 8 years was 56%; patients who received 15 transfusions was 78 and 50%, respectively (P=0.01), whereas it was 67 and 28% for 50 transfusions, respectively (P=0.002). In multivariate analysis, higher number of prior transfusions, shorter period of immunosuppression with cyclosporine and GVHD were associated with inferior survival; moreover, a higher risk of graft rejection were associated with a higher number of prior transfusions and a trend was observed for a shorter cyclosporine administration. Low-dose busulfan is feasible and may be helpful in patients exposed to <50 transfusions. However, rejection remains a significant problem, mainly in heavily transfused patients.     

Alternative donor transplants for patients with advanced hematologic malignancies, conditioned with thiotepa, cyclophosphamide and antithymocyte globulin

Preparative regimens without total body irradiation (TBI) have been reported for alternative donor hemopoietic stem cell transplants (HSCT). Between 7 September 1994 and 7 June 1999 48 patients with advanced hematologic malignancies were conditioned with thiotepa (THIO) 15 mg/kg, cyclophosphamide (CY) 150 mg/kg and antithymocyte globulin (ATG). Donors were HLA mismatched family members (1-2 antigens) (FAM) (n = 24, median age 31 years) or HLA matched unrelated donors (UD) (n = 24, median age 34 years). GVHD prophylaxis was cyclosporine and methotrexate. Stem cell source was peripheral blood (n = 8) or bone marrow (n = 40). Hematologic recovery was seen in 42/46 (91%) evaluable patients and complete chimerism in 31/37 patients (85%). Acute GVHD grades III-IV were seen in 10/46 patients surviving 10 days (21%) and extensive chronic GVHD in 2/36 patients surviving 100 days (5%). Twenty-six patients died (54%), eight of recurrent disease (17%) and 18 of transplant-related complications (37%): main causes of TRM were GVHD (15%), infections (15%) and graft failure (4%). Twenty-two patients (46%) survive with a median follow-up of 877 days (287-1840). The actuarial 3-year survival is 49% for FAM and 42% for UD transplants. Results obtained with this regimen in unrelated grafts for advanced CML (n = 15) were not significantly different when compared to 21 concurrent UD grafts for advanced CML prepared with CY-TBI. In conclusion, the combination of THIO-CY-ATG allows engraftment of alternative donor hemopoietic stem cells. Results are similar when using unrelated matched donors or partially mismatched family donors, and not significantly different when compared to patients conditioned with CY-TBI.     

Fludarabine, cyclophosphamide and horse antithymocyte globulin conditioning regimen for allogeneic peripheral blood stem cell transplantation performed in non-HEPA filter rooms for multiply transfused patients with severe aplastic anemia

Multiply transfused patients of severe aplastic anemia are at increased risk of graft rejection. Five such patients underwent peripheral blood stem cell transplantation from HLA-identical siblings with a fludarabine-based protocol. The conditioning consisted of fludarabine 30 mg/m(2)/day x 6 days, cyclophosphamide 60 mg/kg/day x 2 days and horse antithymocyte globulin (ATG) x 4 days. Two different ATG preparations were used: ATGAM (dose 30 mg/kg/day x 4 days) or Thymogam (dose 40 mg/kg/day x 4 days). Engraftment: median time to absolute neutrophil count (ANC) >0.5 x 10(9)/l was 11 days (range: 8-17) and median time to platelet count >20 x 10(9)/l was 11 days (range: 9-17). At a median follow-up of 171 days (range: 47-389), there has been no graft rejection and all patients are in complete remission. Acute GVHD (grade 1) occurred in one patient only. Chronic GVHD developed in two patients (extensive in one and limited in another). The transplants were performed in non-HEPA filter rooms. In only one patient, systemic antifungal therapy (voriconazole) was used. The use of Thymogam brand of ATG for conditioning is being reported for the first time. Our experience suggests that this fludarabine-based protocol allows rapid sustained engraftment in high-risk patients without significant immediate toxicity.