Treatment of adults with severe aplastic anemia: primary therapy with antithymocyte globulin (ATG) and rescue of ATG failures with bone marrow transplantation.

PURPOSE: To evaluate a policy of immunosuppression with antithymocyte globulin (ATG) as primary therapy for adults with severe aplastic anemia (SAA) regardless of the availability of an HLA-identical bone marrow donor. PATIENTS AND METHODS: Thirty-one consecutive adults with SAA who satisfied the age criteria for allogeneic bone marrow transplantation (BMT) (age less than 51 years) were treated with ATG 20 mg/kg/day for 10 days along with high-dose corticosteroids. Patients with an HLA-identical donor received a transplant if they did not respond to ATG or if they developed life-threatening complications during or soon after ATG administration. Eight patients with no response to ATG were also treated with oral cyclosporine 12.5 mg/kg/day. RESULTS: Eleven patients had a complete and five a partial response to ATG; two patients improved with cyclosporine treatment, resulting in an overall response rate of 58% to immunosuppression. Nine of 14 patients with donors received a BMT: seven because they did not respond to ATG and two because of serious infections. Seven grafts were obtained from related and two from unrelated donors. There was no significant difference in survival between those with and without a related HLA-identical donor (log-rank p value = 0.969). At a median follow-up of 58 months, 26 of 31 are alive with an actuarial survival of 80% at 5 years. Two patients died of infection, two died from complications of BMT, and one remains transfusion-dependent. One patient died of refractory leukemia at 30 months; one patient relapsed with hypoplasia 95 months after initial therapy with ATG. He showed a complete response to treatment with cyclosporine. No other late hematologic events have occurred. CONCLUSIONS: This treatment approach resulted in the restoration of hematopoiesis and independence from transfusion in 80% of patients with SAA entered into the study. The efficacy of allogeneic BMT in salvaging cases in which ATG failed does not appear to be compromised. Follow-up for the development of clonal hematologic disorders remains an important part of this treatment policy.     

Cyclophosphamide and other new agents for the treatment of severe aplastic anemia

Severe aplastic anemia (SAA) has a poor prognosis in the absence of treatment. Current accepted therapeutic strategies include allogeneic stem-cell transplantation and immunosuppression, both resulting in long-term survival in the majority of patients. Although human leukocyte antigen (HLA)-matched sibling stem-cell transplantation is highly effective, the 25% probability of finding a suitable sibling donor within a family renders this approach available to only a minority of patients. Transplantation using HLA-matched, unrelated donors carries a high risk of treatment failure along with considerable toxicity. While combined immunosuppression with both antithymocyte globulin (ATG) and cyclosporine A (CSA) produces hematologic improvement in most patients, relapse is common. Late evolution of aplastic anemia to other serious hematologic disorders, including paroxysmal nocturnal hemoglobinuria (PNH), myelodysplasia, and acute leukemia, is also a significant problem following treatment with ATG/CSA. Recently, results of immunosuppression in SAA with another potent immunosuppressive agent, cyclophosphamide, were reported in a small number of patients. The overall response rate was similar to that seen with ATG/CSA, but relapse and late clonal disease were not observed during a long period of follow-up. A larger randomized trial comparing sustained hematologic response rates to either conventional immunosuppression with ATG/CSA or high-dose cyclophosphamide and CSA is now underway; secondary end points include response duration, event-free survival, and overall survival. Additionally, a number of protocols designed to test the efficacy of alternative immunosuppressive or immunomodulatory agents are being developed.     

Syngeneic peripheral blood stem cell transplantation with brief immunosuppression for severe aplastic anemia

We report the cases of two severe aplastic anemia (SAA) patients who were successfully treated with syngeneic peripheral blood stem cell transplantation (PBSCT) using immunosuppression without high-dose chemotherapy or irradiation for conditioning. A 21-year-old woman with SAA of 6 years duration had been transfused heavily before transplantation and had developed refractory thrombocytopenia, chronic hepatitis and secondary hematochromatosis. Syngeneic PBSCT with immunosuppression using ATG, methylprednisolone, and cyclosporin-A was eventually performed without high-dose chemotherapy in September 1997. The second syngeneic PBSCT with the same immunosuppression was successfully performed in a 35-year-old male patient who had had SAA for 3 months in November 1998. Haemopoietic engraftment was rapid and sustained. There was no infection or mucositis during the syngeneic PBSCT. The patients are currently 9 to 22 months post-PBSCT without rejection. Our experience suggests that syngeneic PBSCT with brief immunosuppression is an effective alternative to pretransplant high-dose chemotherapy conditioning for SAA patients having syngeneic transplantation. Bone Marrow Transplantation (2000) 25, 337-339.     

Deficiency of fibrinogen and factor VII following treatment of severe aplastic anaemia with anti-thymocyte globulin and high-dose methylprednisolone

In 4 patients with SAA treated with ATG and high-dose MP, an as yet unrecognized acquired deficiency of fibrinogen and factor VII was observed. The plasma level of fibrinogen fell to 39% (34-51%) and of factor VII:C to 50% (31-55%) of the pretreatment value. The nadirs were between days 10 and 35 (fibrinogen) and d 3 and 11 (factor VII) after the 1st dose of ATG/MP. From additional clotting studies it is concluded that disseminated intravascular coagulation, fibrinolysis, liver cell damage and synthesis of abnormal clotting factors are unlikely causes of these clotting abnormalities. The most probable explanation seems to be a selective inhibition of the synthesis of fibrinogen and factor VII by an as yet unknown mechanism. These clotting abnormalities might, to some extent, increase the bleeding tendency in these patients, which up to now had been solely attributed to thrombocytopenia.     

High-dose cyclophosphamide as salvage therapy for severe aplastic anemia

OBJECTIVE: The treatment options for patients with aplastic anemia who do not respond to conventional immunosuppression are limited. The aim of this study was to evaluate high-dose cyclophosphamide in patients with refractory severe aplastic anemia (SAA). MATERIALS AND METHODS: We treated 17 SAA patients with high-dose cyclophosphamide (50 mg/kg/day for 4 consecutive days) who previously did not respond to one or more courses of immunosuppressive therapy. Median age was 31 years (range 6-58); median disease duration was 14 months (range 6-58), and 8 patients met criteria for very severe aplastic anemia (absolute neutrophil count <0.2 x 10(9)/L) at the time of treatment. RESULTS: At median follow-up of 29 months, 10 patients (59%) are alive. Nine patients (53%) achieved a drug-free remission after high-dose cyclophosphamide; 4 patients achieved a complete remission and 5 patients currently meet criteria for a partial remission but continue to improve. One nonresponder to high-dose cyclophosphamide developed paroxysmal nocturnal hemoglobinuria; another nonresponder developed a myelodysplastic syndrome. In responding patients, median time to 500 neutrophils was 54 days (range 35-119), median time to the last platelet transfusion was 99 days (range 51-751), and median time to the last red cell transfusion was 125 days (range 63-796). CONCLUSION: High-dose cyclophosphamide shows promise for salvaging patients with refractory SAA.     

Bone marrow transplantation for severe aplastic anemia: a randomized controlled study of conditioning regimens

The addition of antithymocyte globulin (ATG) to a regimen of high-dose cyclophosphamide has been advocated to enhance engraftment after allogeneic bone marrow transplantation (BMT) for severe aplastic anemia (SAA). In a prospective clinical trial, 134 patients were randomly assigned to receive cyclophosphamide alone or in combination with ATG. All patients received T-cell–replete bone marrow from an HLA-matched sibling. With a median follow-up of 6 years, the 5-year probabilities of survival were 74% for the cyclophosphamide alone group and 80% for the cyclophosphamide plus ATG group (P = .44). Graft failure and graft-versus-host disease (GVHD) rates were similar in both groups. With the survival rates achieved, this study is not adequately powered to detect significant differences between the 2 treatment groups. In conclusion, the results of allogeneic BMT for SAA have improved over time related to advances in supportive care. The addition of ATG to the preparative regimen did not significantly improve the outcome.     

Successful allogeneic hematopoietic stem cell transplantation using triple agent immunosuppression in severe aplastic anemia patients

Graft rejection in patients with severe aplastic anemia (SAA) following allogeneic hematopoietic stem cell transplantation (HSCT) is strongly associated with a large number of prior transfusions and with prolonged disease duration before transplant. We retrospectively analyzed the outcomes and the factor affecting these multitransfused SAA patients, who had received triple agent immunosuppression and high doses of stem cells to overcome rejection. In total, 113 patients with SAA who had a median 16 months (range 1-216) of disease duration were transplanted using HLA-matched sibling donors after conditioning with cyclophosphamide (CY), procarbazine (PCB), and ATG. Graft failure occurred in 16 of the eligible 113 patients, and with a median follow-up of 30 months (range, 1-80), probability of overall rejection was 15%. Specifically, the multitransfused patients who received high doses of stem cells with T-cell depletion showed the lowest rejection rate, 5.6%, compared with 30.3% in multitransfused patients with bone marrow stem cells alone (P=0.0310). Disease duration (P=0.0338) and the number of infused CD34+cells (P=0.0101) were associated with a high risk of graft rejection on multivariate analysis. ABO mismatch and the number of CD34+ cells were significant factors in the incidence of acute graft-versus-host-disease (GVHD). The incidence of chronic GVHD among patients with sustained engraftment was 13/109 (11.9%). With the same follow-up period, probability of disease-free survival for the entire group of patients at 6 years was 89% and the only factor associated with long-term survival was rejection (P=0.0241). These results suggest that allogeneic HSCT conditioned with triple agent immunosuppression, and specifically with high-dose stem cell return is probably an effective treatment for successful engraftment in SAA patients with a high risk of rejection.     

High-dose peripheral blood stem cell transplant for multitransfused severe aplastic anaemia patients without antithymocyte globulin in the conditioning regimen.

Four multitransfused patients with severe aplastic anaemia (SAA) are described. Two received a BMT after conditioning with cyclophosphamide (Cy) plus antithymocyte globulin (ATG). Both suffered a graft failure (GF) and had a second transplant with PBSC from the original donor. Two other patients received a PBSCT as a first option, with Cy as the only conditioning drug. The four patients received methotrexate (MTX) and cyclosporine (CYA) as post-grafting immunosuppression. The two BMT patients with GF were successfully rescued with a PBSC second transplant. In the two cases where a PBSCT was done as a first option no GF was observed and a successful and complete haematological recovery was achieved. In conclusion, PBSCT rescued two SAA patients with GF after BMT. PBSCT without ATG as a first option produced a quick and complete haematological recovery in two additional patients, suggesting that PBSCT without ATG can be an alternative to BMT plus ATG in SAA as a first transplant option.     

Overcoming graft rejection in heavily transfused and allo-immunised patients with bone marrow failure syndromes using fludarabine-based haematopoietic cell transplantation

Allogeneic haematopoietic cell transplantation (HCT) can cure a variety of non-malignant haematological disorders. Although transplant outcomes for selected patients with severe aplastic anaemia (SAA) and paroxysmal nocturnal haemoglobinuria (PNH) have improved, older age, allo-immunisation from transfusions, prior immunosuppressive therapy and a prolonged time from diagnosis to transplantation are associated with worse outcome. Because of its potent immunosuppressive effects, we investigated a fludarabine-based non-myeloablative conditioning regimen in patients with transfusion-dependent non-malignant haematological disorders at increased risk for graft rejection with conventional transplant conditioning. Twenty-six patients with transfusion dependent/anti-thymocyte globulin (ATG)-refractory SAA, PNH or pure red cell aplasia underwent HCT from a human leucocyte antigen (HLA)-compatible relative. Transplant conditioning consisted of cyclophosphamide (120 mg/kg) and fludarabine (125 mg/m2) with or without ATG. Ciclosporine, alone or combined with mycophenolate mofetil or methotrexate, was used as graft-versus-host disease (GVHD) prophylaxis. All patients achieved durable engraftment and transfusion-independence. Twenty-four of 26 patients are alive at a median of 21 months following transplantation. Although a high cumulative incidence of acute (65% grades II-IV, 54% grades III-IV) and chronic GVHD (56%) was observed, only one patient died from transplant-related causes (cumulative incidence 7%). These data show that HCT following fludarabine-based non-myeloablative conditioning results in durable engraftment and excellent survival in SAA and PNH patients at high risk for graft rejection.     

Remission induction in a patient with severe aplastic anemia and renal failure by immunosuppressive treatment including antithymocyte globulin

Summary The pathogenesis of severe aplastic anemia (SAA) is still unclear. Based on clinical and experimental data the hypothesis has been put forward that autoimmune mechanisms may be involved. Encouraging results have been presented with various immunosuppressive drugs including antithymocyte globulin (ATG). We report the successful treatment of SAA with bolus methylprednisolone and ATG in a patient with high-grade renal failure. ATG was tolerated without side effects.     

Oral cyclosporin-A is effective treatment for untreated and also for previously immunosuppressed patients with severe bone marrow failure

16 patients with transfusion-dependent, life-threatening bone marrow failure (14 with severe aplastic anaemia, 1 with systemic lupus erythematosus and 1 with pure red cell aplasia) were treated with cyclosporin-A (Cy-A) after either lack of response to conventional immunosuppression with antithymocyte-globulin/high-dose methylprednisolone for 95 to 1190 days (median 186.5) (group I, 8 patients) or as a primary treatment due to ineligibility for conventional immunosuppression (group II, 8 pat.). Cyclosporin-A was given orally to maintain trough levels of 200 to 300 ng/ml (RIA). In group I, 6 out of 8 patients responded 30 to 480 d (median 53) and are currently alive 627 to 1482 d (median 731) after initiation of Cy-A, respectively. In 3 of the responders Cy-A has been withdrawn, without relapse. In group II, 5 of 8 patients responded 26 to 170 d (median 63) and are currently alive 142 to 697 (median 420) d following initiation of Cy-A, respectively. These data indicate a place for cyclosporin-A in the management of patients with life-threatening bone marrow failure in whom a) immunosuppressive therapy with antithymocyte-globulin and high-dose methylprednisolone had failed and b) who are not candidates for vigorous immunosuppression or bone marrow transplantation, for medical or other reasons.     

非清髓性造血干细胞移植治疗血液病预处理中ATG／ALG的应用及作用

目的：探讨抗胸腺细胞球蛋白（ATG）和抗淋巴细胞球蛋白（ALG）在血液病非清髓性异基因造血干细胞移植中的作用，以及ATG/ALG的毒副作用，对移植并发症的影响。方法：以ATG／ALG为基础降低化疗剂量的非清髓性预处理方案，对16例恶性血液病、17例重型再生障碍性贫血（SAA）实施骨髓、骨髓加外周血造血干细胞或脐血造血干细胞移植；对5例恶性血液病实施逐渐增加剂量的供者淋巴细胞输注（DLI），1例S从实行供者干细胞输注（DSI）。GVHD的预防：恶性血液病采用环孢菌素A联合短程甲氨喋呤，SAA患者采用CSA联合甲泼尼龙。采用糖皮质激素和甾体类消炎药等防治ATG／ALG毒副作用和并发症。结果：3例患者在移植后早期感染死亡。其余30例患者恢复造血功能，ANC〉0．5×10^8/L和PLT〉20×10^9／l平均时间为12．2（3-35）d和20．1（5～80）d。移植后7例为供者型完全嵌合体（CC），3例无植入证据；23例为混合性嵌合体（MC），其中7例逐渐转为CC，6倒是在DLI或者DSI后实现MC向CC转变。移植后早期均无aGVHD，3～8次DLI并发Ⅰ度aGVHD1例、Ⅱ度aGVHD3例，2例皮肤局限型cGVHD、2例为广泛型cGVHD。并发严重的细菌感染3例、病毒感染4例、真菌感染5例。ATG／ALG使用过程中全部出现寒战、发热症状，大部分出现皮疹、一过性血压下降、少数出现一过性心律不齐，经积极防治不需中断治疗。结论：ATG／ALG促进异基因造血干细胞的植入，延迟和减少GVHD的发生率并降低严重程度．是否增加病毒、真菌感染的机会有待进一步观察。     

Long-term results of the immunosuppressive treatment of patients with severe acquired aplastic anemia: a single institution study

In México, only few patients can afford adequate treatment for aplastic anemia. In a single institution 61 individuals with severe aplastic anemia (SAA) were identified; of these, 33 were followed for at least 3 months, 26 could be treated with immunosuppression (IS), 20 with antithymocyte globulin and cyclosporin A (ATG + CyA) and 6 with CyA, whereas 7 individuals were given only anabolic androgens. In the patients treated with IS a complete remission was achieved in 12 and a partial remission in 6, the overall response rate being 69%. The 5,729-day overall survival (SV) was 54%; it was superior for the patients who received both ATG and CyA (58 vs. 50%). These data contrast with those of the patients who were given only androgens: 14% SV at 5,510 days. Within the group of patients who received IS, one developed acute myelogenous leukemia, another paroxysmal nocturnal hemoglobinuria and another a primary Sj?gren's syndrome-associated low-grade, B cell, non-Hodgkin's lymphoma. Two individuals who received IS were allografted from HLA-identical siblings and survived 70 and 413 days after the allograft. On the other hand, we also found that, for several reasons, mainly economic ones, only 41% of individuals with SAA finally benefited from the best immunosuppressive therapeutic approach. IS was a good therapeutic choice for some patients with SAA, clearly better than androgen treatment.     

Treatment of Hematologic Malignancies with Alternate Hemibody Irradiation Combined with High-Dose Chemotherapy: A Single-Center Experience

The objective of this study was to evaluate the clinical outcome of the treatment of hematologic malignancies with alternate hemibody irradiation (AHBI) combined with high-dose chemotherapy. Seventeen patients with hematologic malignancies were treated with AHBI combined with high-dose chemotherapy. Following high-dose chemotherapy, upper hemibody irradiation (UHBI) and lower hemibody irradiation (LHBI) were given sequentially in a dose of 6 to 9 Gy. UHBI was given 14 days (range, 12-22 days) after high-dose chemotherapy, and LHBI was performed 23 days (range, 7-34 days) after UHBI. Meanwhile, we treated a control group of 14 patients with acute lymphoblastic leukemia (ALL) with autologous hematopoietic stem cell transplantation (AHSCT). Hematopoietic reconstitution was observed in all of the patients. The median follow-up period was 927 days (range, 428-1446 days). The 3-year probabilities of disease-free survival (DFS) were 52.38% +/- 13.47% for the patients in complete remission who underwent AHBI. No patient died of AHBI-related toxicity. The 3-year DFS rates for the 2 groups of patients with ALL were not significantly different (47.73% +/- 17.55% in the AHBI group and 53.88% +/- 14.08% in the AHSCT group; P > .05). AHBI combined with high-dose chemotherapy is a feasible approach for patients with hematologic malignancies and has the advantages of a desirable effectiveness, low costs, simple operation, and acceptable side effects.     

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.     

Outcome of immunosuppressive therapy for myelodysplastic syndromes: results of 12 cases from a single institution

Twelve transfusion-dependent patients with myelodysplastic syndrome (MDS) were treated with immunosuppressive therapy; 8 with cyclosporin A (CyA), 3 with CyA and antithymocyte globulin (ATG), one with ATG. G-CSF was combined in 10 patients. Eight patients who consisted of 4 treated with CyA, 3 with ATG/CyA, and one with ATG, achieved transfusion-independence. Responses were observed in 8/9 patients with refractory anemia, 0/3 patients with refractory anemia with excess of blast, although the recovery was incomplete in most cases. All of the CyA-responsive patients took drug-dependent courses. The presence of GPI-anchored protein-deficient granulocytes (CD11b+CD55-CD59-) was examined by flow cytometry after treatment in 6 responsive patients, and was demonstrated in 2 of them. HLA-DR15 was found in 5 of 7 responsive patients, suggesting that the presence of this allele may be associated with a good response to immunosuppressive therapy. All responsive patients had refractory anemia classified to IPSS Int-1, and had common conditions as follows: absence of chromosomal abnormality, short interval from diagnosis to therapy, and employment of ATG therapy.     

Long-term marrow culture in patients with aplastic anemia compared with marrow transplant recipients and normal controls.

Patients with severe aplastic anemia (SAA; n = 46) were studied in long-term bone marrow culture (LTBMC) systems and compared with allogeneic marrow transplant (BMT) recipients (n = 16) (within 30 days following BMT) and normal control patients (n = 12). SAA patients were divided in two groups: transfusion-dependent (Tx-D) SAA patients (group A; n = 15) and transfusion-independent (Tx-I) patients after treatment with antilymphocyte globulin (group B; n = 31). Cultures were analyzed at three levels: stromal layer (SL) formation (score: 0, no SL; 1, half confluent SL; and 2, confluent SL), number of nucleated cells in suspension, and growth of CFU-GM colonies. SL formation was rapid and complete in SAA patients, groups A and B (mean score on day 14: 1.3 and 1.4), similar to controls (mean score on day 14: 1.3), whereas an impairment of SL formation was seen in BMT recipients (mean score on day 14: 1.0). The number of nucleated cells in suspension increased significantly on day 7 of culture in controls (7.6-fold), significantly more than in BMT and SAA patients, and declined thereafter. Colony formation was also significantly increased on day 7 in Tx-I SAA patients, BMT recipients, and normal controls (4-, 5-, and 16-fold, respectively), lasting respectively 2, 3, and 4 weeks. Increments of colony formation were also obtained in Tx-D SAA patients, but in the first week of culture only. In conclusion: 1) a significant impairment of SL formation was seen in BMT recipients, but not in SAA patients; 2) a significant increment of granulocyte-macrophage colony-forming units (CFU-GM) growth can be obtained in patients with marrow failure early after starting long-term culture; 3) the number of CFU-GM grown in these culture conditions from Tx-I SAA patients parallels the number of progenitors from early post-BMT recipients; and 4) progenitor cells from Tx-D SAA patients are not only reduced in numbers, but also exhibit a poor ability to survive in LTBMC.     

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.     

Haematopoietic and immunologic abnormalities in severe aplastic anaemia patients treated with anti-thymocyte globulin

Summary. Thirty-five patients with severe aplastic anaemia (SAA) were extensively evaluated 0.3-12.4 years (median 3.8) after anti-thymocyte globulin (ATG) treatment. All but one were transfusion independent. Most patients revealed a normal Hb level and a granulocyte count over 1.5 × 10⁹/1 but were still thrombocytopenic due to decreased platelet production. Lymphocytopenia and/or monocytopenia was found in about 30%. Two patients had a monocytosis. Although there was a great range in degree of recovery at various time intervals after ATG. patients tested more than 4 years after ATG tended to have higher cell counts. Lymphocyte counts correlated with the interval between ATG and evaluation, and with haematopoietic recovery. Qualitative abnormalities were found in all cell lines. Most patients showed a homogeneous macrocytic RBC population, and almost 50% a positive sucrose lysis test: only three patients showed evidence of haemolysis and only two of these showed a positive Ham test. Mean platetet volumes were reduced out of proportion to their number. Platelet function, determined by bleeding time and aggregometry, was impaired in over 30%. The granulocytic series showed a shift to the left in about 30%. Hypersegmentation and pseudo Pelger-Huet anomaly were seen in some patients. Lymphocyte subset distribution in blood and bone marrow was within the normal range but absolute blood levels of CD4 cells in particular were slightly decreased, and tended to increase gradually with time after ATG. IgG and IgA levels were significantly decreased. In only one patient cytogenetic analysis of unstimulated bone marrow cells revealed an abnormal karyotype, but in eight of eight patients an increased sensitivity of lymphocytes to X-rays was found. These data suggest impairment at the level of the very early haematopoietic progenitor cell in all patients up to 10 years after ATG. Since similar findings have been reported in clonal (pre-)malignant disease, SAA, improved after ATG treatment, might be prone to clonal (malignant) evolution.     

Does early treatment with high-dose methylprednisolone alter the course of hepatic regimen-related toxicity?

Hepatic regimen-related toxicity (RRT) is a serious complication of stem cell transplantation. Cytokine activation may be involved in the pathogenesis. Corticosteroids are potent inhibitors of cytokine production, and, therefore could play a role in the treatment of hepatic RRT. Between January 1994 and June 1998, 28 of 782 consecutive transplant patients (3.6%) developed hepatic RRT (20 veno-occlusive disease (VOD) and eight liver dysfunction of uncertain etiology (LDUE) as defined by Seattle criteria), and were treated with high-dose methylprednisolone (MP, 500 mg/m2 i.v. every 12 h for six doses), initiated upon increase in serum total bilirubin to > or =4 mg/dl. Other causes of liver dysfunction were excluded. Response to therapy with high-dose MP was defined as reduction in total bilirubin by 50% within 10 days of initiation of MP. Overall, 17 patients (61%) responded to treatment (12 patients with VOD, five patients with LDUE). The bilirubin in responding patients decreased from a mean of 8.6 mg/dl (range, 4-17.9) at the start of MP to 4.1 mg/dl (range, 0.5-17.9) 10 days later. There were no statistically significant differences between responders and non-responders in the day treatment with high-dose MP was initiated (P = 0.38), total serum bilirubin (P = 0.17) and percent weight gain at the time high-dose MP was started (P = 0.10) or the calculated probability of fatal outcome from VOD (18% for responders, 23% for non-responders; P = 0.30). A lower pre-transplant DLCOc was observed among non-responders (P = 0.04). At 100 days post-transplant, hepatic RRT resolved in all 13 survivors who responded to high-dose MP, and in one non-responding patient. No serious toxicities due to high-dose MP were observed. We conclude that resolution of hepatic RRT occurred in the majority of patients treated with high-dose MP in this study; however, randomized controlled trials are required to determine the efficacy of high-dose MP for treatment of hepatic RRT.