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

Background: Thrombocytopenia has been reported to be associated with efalizumab therapy, but has only sporadically been reported with other anti-tumor necrosis factor alfa (TNF-alpha) agents. Objective: To describe the frequency of thrombocytopenia in a cohort of patients who underwent biological therapies for psoriasis. Methods. This was a retrospective observational study of 93 patients. Results: One hundred eighteen Courses of biological therapies were administered to 93 patients. Four of 67 patients who received anti-TNF-alpha 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-alpha 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%). Limitations: These findings should be validated in larger studies. Conclusions: Drug-induced thrombocytopenia is a potential side effect of anti-TNF-alpha agents. Immediate monitoring Of Platelet Counts is recommended if autoimmunity is suspected. (J Am Acad Dermatol 2009;60:781-5.)