Monitoring of Patients Receiving Immunosuppressive and Biological Agent Treatments for Infectious Complications.

Objective: This study aimed to evaluate the occurrence of infectious complications in rheumatology patients receiving various biological agent therapies. Materials and Methods: Patients who received biological disease-modifying antirheumatic drugs (bDMARDs) were prospectively followed for two years. Results: A total of 235 patients were included in the study. Among the patients, 158 (67.3%) received anti-tumor necrosis factor (TNF) therapy and 77 (32.7%) received non-anti-TNF biological agents. A positive tuberculin skin test was observed in 31.5% of patients, and interferon-gamma release assay (IGRA) was positive in 10.6%. Latent tuberculosis reactivation occurred in 2 patients (0.8%) undergoing anti-TNF therapy. Of the 50 patients monitored for hepatitis B virus reactivation (HBVr), all were anti-HBc IgG-positive, and 5 (10%) were HBsAg-positive. Among them, 29 (58%) were followed preemptively, and 21 (42%) received prophylactic antiviral therapy. HBVr developed in 3 of 10 patients (30%) in the high-risk group, compared to 1 of 35 patients (2.8%) in the low-risk group. Bacterial infections -occurred in 29.8% of patients, with serious infections in 4.7% (n=11) and non-serious infections in 25.1% (n=59). Herpes zoster was reported in four patients, corresponding to an incidence rate (IR) of 0.88 per 100 person-years. Vaccination coverage was 23.8% for influenza, 4.7% for 23-valent polysaccharide pneumococcus, 3% for 13-valent conjugated pneumococcus, and 42.6% for HBV. Conclusions: Biological agents, due to their mechanisms of action, target various key molecules in the immune response against infectious antigens. Therefore, comprehensive risk assessment for infections and review of vaccination status are essential prior to initiating biological therapy. Stratifying patients based on the infectious risk profile of the biological agent is crucial for safe and effective treatment.