Chloroquine diphosphate: a risk factor for herpes zoster in patients with dermatomyositis/polymyositis

da Cunha, Gilmara Franco; de Souza, Fernando Henrique Carlos; Levy-Neto, Maurício; Shinjo, Samuel Katsuyuki

In contrast with other systemic autoimmune diseases, in which impaired cellular immunity is considered a risk factor for HZ development (12) , humoral immunity function might be considered relevant in inflammatory myopathies because the prevalence of HZ was higher in the DM patients compared to the PM patients. From an immunopathological standpoint, CD8 (+) lymphocyte and macrophage infiltrations are primarily found in PM muscle fibers (22) , whereas in DM, B cells play important roles in the pathogenesis of the disease through the presence of autoantibodies, immune complex deposition in the dermoepidermal junction of skin lesions and the presence of B cells in inflamed muscles and perivascular areas (23, 24) . Additionally, deposition of complement and immunoglobulin in the perifascicular endothelium can lead to ischemia and muscle atrophy, underlining the importance of humoral immunity (25) . Thus, disturbances in humoral immunity might increase HZ reactivation, as we found a higher prevalence of HZ in the DM patients compared to the PM patients.