Thrombocytopenia associated with the use of anti–tumor necrosis factor–α agents for psoriasis

BackgroundThrombocytopenia has been reported to be associated with efalizumab therapy, but has only sporadically been reported with other anti–tumor necrosis factor alfa (TNF-α) agents.ObjectiveTo describe the frequency of thrombocytopenia in a cohort of patients who underwent biological therapies for psoriasis.MethodsThis was a retrospective observational study of 93 patients.ResultsOne hundred eighteen courses of biological therapies were administered to 93 patients. Four of 67 patients who received anti-TNF-α agents developed drug-induced thrombocytopenia during treatment, compared with none of the 51 patients receiving efalizumab therapy. The platelet count recovered after suspension of anti-TNF-α agents in 3 patients and relapsed after re-exposure in two patients. The overall estimated frequency of thrombocytopenia in our cohort was 4.30% (95% confidence interval [CI], 0% to 6.2%).LimitationsThese findings should be validated in larger studies.ConclusionsDrug-induced thrombocytopenia is a potential side effect of anti-TNF-α agents. Immediate monitoring of platelet counts is recommended if autoimmunity is suspected.