INTRAVENOUS PROSTACYCLIN (AS EPOPROSTENOL) INFUSION IN THROMBOTIC THROMBOCYTOPENIC PURPURA - 4 CASE-REPORTS AND REVIEW OF THE LITERATURE

Background. The enhanced platelet aggregation which is observed in Tip , was suggested to be due to an imbalance between unknown agents insul ting endothelial wall and defense factors, such as prostacyclin (PGI(2 )). Several reports suggested an aberration of PGI(2) activity as a cr itical step in the pathogenesis of TTP. Therefore, PGI(2) was proposed as an alternative treatment for TTP patients. Methods. We report the results obtained with increasing doses (from 2 ng/Kg/min to 10 ng/Kg/m in in 5 days) of PGI(2) - as epoprostenol - in 4 TTP patients from the retrospective series of the Italian Cooperative Group who were consid ered resistant to conventional plasma-exchange (PE)-based treatments. Results. Despite PGI(2) infusion, 2 patients died, while the extant 2 achieved stable complete remission. Notably, the only patient whose PE was administered with adequate frequency and for an adequate period o f time, and thus the only unquestionably PE-resistant patient, was als o resistant to PGI infusion. Major side-effects were few and observed at the highest doses. 2 Conclusions. In our experience and from the an alysis of the literature, which, as far as we know, includes only 23 p atients treated with PGI(2)-like substances, the role of PGI(2) in the treatment of TTP appears to be modest. Maybe the identification of su bgroups of TTP patients exhibiting some defects in PGI metabolism, tog ether with the use of more manageable PGI(2) analogs, such as iloprost , could revive interest in these molecules in the future.