[Infections in polymyositis and in dermatomyositis]

Area of Science:

• Rheumatology
• Infectious Diseases
• Immunology

Background:

• Infections are a major cause of mortality in polymyositis/dermatomyositis (PM/DM), accounting for 9-30% of deaths.
• Patients with PM/DM are susceptible to both pyogenic and opportunistic infections.

Purpose of the Study:

• To identify predictive factors for infection onset in PM/DM patients.
• To discuss appropriate prophylactic measures against infections in PM/DM.

Main Methods:

• Review of clinical parameters associated with infection risk in PM/DM.
• Analysis of common pathogens causing infections in PM/DM.
• Evaluation of strategies for infection prevention, including vaccination and primary prophylaxis.

Main Results:

• Predictive factors for infection include age, lymphopenia, esophageal dysfunction, ventilatory insufficiency, interstitial lung disease, calcinosis cutis, and high steroid doses.
• Mycobacteria and fungi (e.g., Pneumocystis jiroveci, Candida) are common causes of opportunistic infections.
• Primary prophylaxis for Pneumocystis jiroveci pneumonia is recommended for patients with CD4 counts below 250/mm³.

Conclusions:

• Implementing preventative strategies, such as vaccination before immunosuppression and targeted prophylaxis, is crucial for reducing infection-related mortality in PM/DM.
• Prophylaxis against Pneumocystis jiroveci pneumonia should be considered for immunocompromised PM/DM patients.