Twenty-three consecutive adults with bone marrow aplasia who, apart from one individual, lacked a sibling suitable for allogeneic transplantation, received five daily infusions of 50 mg/kg of antilymphocyte globulin (ALG) concurrently with high-dose (500 mg) methylprednisolone (HDMP), followed by oral prednisone at a dose of 30 mg until day 30. One patient died early so that response could not be determined, but data are available and included in the toxicity as well as survival analysis. Haematological response occurred in 13 of the remaining 22 (59%). This followed a single course of treatment in 12, with complete response achieved in five of this group and a second course required in one. At a median follow-up of 20 months (range 5-60), there have been five relapses and 13 patients are alive, including 12 responders who have Karnofsky ratings between 90% and 100%. Of the other nine individuals, only two are alive, with 1 at 12 months still requiring active support and the second, after failing further courses of treatment, at 41 months having a partial response to lymphocytapheresis and plasma exchange. Failure to respond was a significant adverse predictor for survival (P = 0.022). This study involved two distinct batches of ALG, with response occurring in 1/7 (14%) patients treated with the first lot, but in 12/15 (80%) of those individuals who were treated with the second (P = 0.007). Only a pretreatment mean cell volume (MCV) greater than 100 fL predicted for response (P = 0.0088). Confirmation is hereby provided for the efficacy of ALG used in combination with HDMP for treatment of aplastic anaemia, with further support for the observation that not all batches of this product are comparable in bringing about haematologic response in these individuals.
