TNF-alpha Inhibitors and Neutropenia: Current State of Art

Drug-induced severe neutropenia, defined as an absolute neutrophil count (NC) ≤ 0.5 x 109/L or a complete lack of neutrophils in circulating blood, is a potentially severe complication that has been related to most classes of drugs [1]. For the majority of drugs, the risk is likely to be very small. For medications such as antithyroid drugs, ticlopidine, clozapine, cotrimoxazole (trimethoprimsulfamethoxazole), sulfasalazine, methimazole, and dipyrone, the risk may be higher [2,3]. Although the pathogenesis is not yet fully clear, direct toxicity to the myeloid cell line and immune-mediated destruction are the main reported mechanisms [4].