Infections and vaccinations as possible triggers of inflammatory myopathies

The role of vaccinations and infections in triggering idiopathic inflammatory myopathies (IIM) has not been confirmed.

Among patients with histologically confirmed myositis, infections or vaccinations administered prior to myositis onset were determined. The characteristics of this group were compared with controls (myositis patients without prior infection or vaccination).

The frequency of IIM with a prior vaccination was 20 of 206 (9.7%), infection was 29 of 206 (14%), and either vaccination or infection was 49 of 206 (23.8%). Dermatomyositis (DM) was more frequent among patients with preceding vaccination (P = 0.03) or prior infections (P = 0.02) than among controls. Antibodies to Ro52 were more frequent among patients with preceding vaccination than among controls (P = 0.002).

Although causality is not shown, the occurrence of prior infection or vaccination in 24% of patients with IIM prompts further inquiry. The overrepresentation of DM in those with preceding vaccination and the possible role of antibodies to Ro52 in susceptibility to vaccine-induced myositis require confirmation. Muscle Nerve 56: 987-989, 2017.