Elevated plasma interleukin-17A in a subgroup of Myasthenia Gravis patients

To better define the role of IL-17A in myasthenia gravis (MG), we assessed plasma concentrations in 69 adult patients with MG prior to initiation of immunosuppression and monitored their clinical course for the subsequent 2 years with quantitative MG scores (QMGS) and Osserman classification. IL-17A was higher among patients than healthy control subjects. Early-onset women without thymoma had greater elevations of IL-17A. Logistic regression analysis indicated that the absence of thymoma rather than women gender or early-onset was the significant determinant associated with IL-17A elevation. Elevated IL-17A levels were associated with more severe MG. In summary, IL-17A has role in the pathogenesis of a subgroup of patients with early-onset women with MG with greater disease severity who are most likely to have thymic hyperplasia. This subgroup may be a target for IL-17 treatments, which are under development. (C) 2015 Elsevier Ltd. All rights reserved.