Frequency of thrombocytopenia in psoriasis patients treated with tumor necrosis factor-a inhibitors

Tumor necrosis factor-? (TNF-?) inhibitors are biologic agents that are currently in wide use for the treatment of psoriasis as well as other inflammatory diseases. Following reports of thrombocytopenia as a potential adverse effect of anti-TNF-? therapy, we performed a retrospective study to determine the frequency of thrombocytopenia, defined as a platelet count <50x109 cells/L, in a cohort of 187 psoriatic patients treated with anti-TNF-? agents over a nine-year period. Although none of our patients met serologic criteria for thrombocytopenia or displayed clinical manifestations of thrombocytopenia, two patients developed platelet counts below 100×109 cells/L. Thrombocytopenia induced by anti-TNF-? agents is a potential adverse effect, it is a rare occurrence that will require further investigation in large, placebo-controlled, double-blind, prospective studies.