We conducted a structured review of the literature to evaluate opportunistic infections in patients with immune-mediated neuromuscular disorders, and the types of immunosuppressive therapy used when infections developed.

Immune-mediated neuromuscular disorders often require chronic immunosuppressive treatment. The use of chronic immunosuppressive therapy raises concerns about infection risk, including opportunistic infections. Currently, there is lack of clear evidence on the role of infection prophylaxis in neuromuscular patients on chronic immunosuppression.

We conducted a comprehensive literature search over a 20 year period. A search string was used to identify autoimmune and inflammatory neuromuscular disorders and opportunistic infections. We analyzed type of infection, neuromuscular disorder, and immunomodulating therapies.

We find that a wide range of opportunistic infections has been reported, including atypical pathogens and viral infections. Infections were most commonly reported in patients with inflammatory myopathies (81% of infections). Fewer opportunistic infections have been reported in myasthenia gravis, and only one opportunistic infection has been reported in inflammatory neuropathies. Most patients were on more than one immunosuppressant (61.5%), and the vast majority were on steroids (90.6%).

The findings suggest that, in this population, greater immunosuppression predisposes to opportunistic infections of varying types.  Infections are most commonly reported in myositis, which may reflect a tendency in this disease or reporting bias in the literature. The relative lack of reported infections in inflammatory neuropathies suggests opportunistic infections in inflammatory neuropathies may be underreported. Based on currently available suggestions for prophylaxis in other diseases, PJP prophylaxis may be considered on a case by case basis for neuromuscular patients, but there is no clear benchmark for when to start prophylaxis. Prophylaxis for other infections appears unlikely to be of benefit. The results and limitations of this study highlight the need for further reporting of infections and investigations into the utility of infection prophylaxis in this patient population.