Immune suppression therapy in aplastic anemia: influencing factors on response and survival

OBJECTIVES

Immune suppression (IS) therapy has provided another opportunity of cure or improvement in the aplastic anemia patients who cannot receive bone marrow transplantation due to many causes. There are a few reports regarding the factors that affect response, survival and prognosis after IS therapy, including antilymphocyte globulin (ALG) in aplastic anemia. Therefore, we analysed our experience to determine the prognostic factors.

METHODS

Statistically analysed were 172 patients, from April 1982 to July 1992, who were diagnosed as severe aplastic anemia and treated with IS therapy, including ALG, at Catholic University Medical College, St. Mary's Hospital.

RESULTS

Among 172 severe aplastic anemia (SAA) patients who entered the study from April 1982 to July 1992, 144 patients were analysed for response and 122 patient for survival. 58.4% (84/144) responded after the first course of IS therapy. Among those who did not respond on the first course an additional 44% (11/25) responded after the second course of IS therapy. Prognostic factors that might affect the response to the treatment and survival were analysed. In a univariate analysis of patients with no previous history of treatment before is therapy, and a shorter interval between diagnosis and treatment, higher hemoglobin levels before IS therapy, and higher granulocyte counts and combined use use of cyclosporin A(CSA) were positively associated with response (p < 0.05). The combined use of CSA during IS therapy, younger age, lower monthly requirement of platelets transfusion before IS therapy, higher leukocyte counts, higher percent of polymorphonuclear leukocytes, lower percent of lymphocyte, higher bone marrow cellularity and response were positively associated with survival (p < 0.05). In a multivariate analysis, shorter interval between diagnosis and treatment, no combined use of hemopoietic stimulants, such as androgen, and lesser total amount of transfusion were positively associated with Response (p < 0.05). Higher leukocyte counts before IS therapy and the combined use of CSA during IS therapy were significantly associated with longer survival (p < 0.05). Patients with complete or partial response had excellent prognosis (96.7%-100% of 5 year survival rates). In contrast, patients with no response after IS therapy had 45.1% of 5 year survival rates.

CONCLUSIONS

With these results from the retrospective study of IS therapy, we find many valuable factors that have an influence on response or survival. IS therapy improves the survival of responded patients with SAA, and we confirmed that IS therapy is an important therapeutic tool for the SAA patients who are not feasible candidates for bone marrow transplantation.

Immunomodulation therapy for severe aplastic anemia--ALG versus ALG plus cyclosporin A

Immunosuppressive treatment of aplastic anemia has been increasingly used as an alternative treatment to bone marrow transplantation. In this study, the additive effect of Cyclosporin A (CSA) (5mg/kg/day, at least 3 months) for maintenance of immunosuppression after antilymphocyte globulin (ALG) therapy (40mg/kg/day for 4 days) was compared to the previous ALG alone treatment (15mg/kg/day for 10 days). A high dose of methylprednisolone (20mg/kg/day for 5 days and 10mg/kg/day for 5 days) to the ALG group and a low dose of methylprednisolone (2mg/kg/day for 5 days) to the ALG plus CSA group were administered simultaneously. The results were as follows: 1) Sixteen (69.6%) out of twenty-three patients treated with ALG plus Cyclosporin A showed higher responses (CR: 48%, PR: 22%). On the contrary, nine out of nineteen in the ALG group showed lower responses (CR: 21%, PR: 26%). 2) Our data showed a tendency that male patients in age ranging from sixteen to thirty years showed an excellent response to ALG therapy (12/23: 52.2%). 3) The ALG plus CSA group revealed a faster response compared to the ALG alone group (15/16 within 6 months). 4) We speculate that ALG plus CSA therapy might be the treatment of choice for patients with a moderate degree of aplastic anemia. 5) Adding CSA to ALG increased the chance of infection, such as those with URI-like symptoms, but it did not affect the mortality rate. Our data suggest that the ALG plus CSA regimen may be a more useful therapeutic modality for patients with severe aplastic anemia who cannot be candidates for bone marrow transplantation and a randomized multicenter study is needed for confirmation of our preliminary study.