EFFECTS ON PLATELET-FUNCTION BY HUMAN INTERFERON-BETA IN CARCINOMA PATIENTS

The effects of a therapeutic course of human interferon-beta (Hu IFN-b eta) on platelet function were evaluated in 10 patients with neoplasti c disorders. Each patient received, by intra-muscular route, 6 x 10(6) IU of Hu IFN-beta every other day for 2 weeks. Platelet count, packed platelet volume, platelet size and in vitro aggregation tests were ev aluated before IFN treatment and weekly during the treatment. An overa ll increase of in vitro platelet aggregation was present in all patien ts after the first week, and persisted after the second week of treatm ent. This effect was most pronounced when ADP and collagen were used a s aggregation inducers. No significant differences were observed in IF N-gamma IL-6, IL-1 beta and GM-CSF serum levels before and after IFN-b eta treatment; nevertheless a parallel rise in IL-1 beta and/or GM-CSF and platelet count was noticed. The results obtained indicate that th e effects of IFN-beta on platelet function are most likely due to a di rect influence on bone marrow.