Treatment of acquired severe aplastic anemia with antilymphocyte globulin, cyclosporin A, methyprednisolone, and granulocyte colony-stimulating factor.

Fifty-six adult patients with newly diagnosed acquired severe aplastic anemia (SAA) received horse antilymphocyte globulin (ALG), cyclosporin A (CyA), methylprednisolone (Mpred), granulocyte colony-stimulating factor (G-CSF) as first-line therapy. The median age was 34 (range, 17-72) and median neutrophil count 0.280 x 10(9)/L. Trilineage hematologic recovery (at a median interval of 105 days from treatment) was seen in 46 patients (37 complete, 9 partial) after one (n = 38) or two (n = 8) courses of ALG. Cytogenetic abnormalities were observed in three unresponders, clonal hematologic disease in three complete responders, and relapse of marrow aplasia in four complete responders. Median follow up for surviving patients was 1,668 days (range, 237-4,012). The actuarial survival at 5 years was 82%, falling to 77.1% at 7 years and was stationary at 7 and 8 years. Survival was not influenced by the neutrophil count (72% vs. 87%, for neutrophils less than vs. greater than 0.2 x 10(9)/L; P = 0.54). Immunosuppressive treatment of SAA with the 4-drug combination appears to be effective. The significant prognostic effect of an enduring increase of the white blood cell (WBC) count during G-CSF treatment may suggest complete and partial response to therapy. In nonresponders, the WBC count either did not change or elevated values gradually returned to nearly their initial levels while the patients were still under G-CSF treatment. In patients not responsive to treatment but living under CyA and G-CSF, the possibility of developing cytogenetic abnormalities does not seem to be low, despite the absence of findings attributable to manifest myelodysplastic syndrome.