Background: The role of comorbid infections (CI) in rheumatology is still great. Increasingly active use of genetically engineered biological agents (GEBA) and glucocorticosteroids (GCS) exacerbates the existing immunodeficiency.
Objective. Assessment of the the frequency, structure and risk factors for CI in rheumatic diseases.
Methods. A retrospective analysis of the case histories of patients who were hospitalized at the Rheumatology Department of the Republican Hospital named after A.I. V.A. Baranov (Petrozavodsk) in 2018–2022 was performed. All infections that had clinical or laboratory manifestations were taken into account. Statistical analysis of the results obtained was carried out using the Statistica 13.3. Differences were considered statistically significant at p<0.05.
Results: Patients with rheumatoid arthritis [RA] predominated among hospitalized patients (≈40%). From 53 to 80% of patients with RA received GEBA therapy. In the group of patients with RA who received GEBA, viral infections of the respiratory tract predominated. In the group of patients treated with traditional disease-modifying anti-rheumatic drugs (DMARDs), bacterial infections of various localizations had a greater proportion. The relationship between the development of CI and RA activity (p=0.005), as well as GCS therapy at a dose of 7.5 mg/day and more prednisolone equivalent was statistically significant (p=0.016).
Conclusion: The number of CIs in RA was 49.09% of the total number of infections in rheumatic diseases over 5 years; their structure differed depending on the type of DMARD therapy. The identified risk factors for CI included RA activity (P=0.005) and GCS therapy at a dose of 7.5 mg/day and more prednisolone equivalent (P=0.016).

Keywords: comorbid infections, genetically engineered biological agents, rheumatic diseases, glucocorticosteroids, rheumatoid arthritis