Infections and causative microorganisms in patients with ANCA-associated vasculitis

Abstract

Purpose: The aim of this study was to detect infections requiring hospitalization in patients with ANCA-associated vasculitis (AAV). Materials and Methods: This is a single-center, retrospective study conducted in Turkish patients with AAV. Infection episodes requiring hospitalization, reproducing pathogens, laboratory findings, immunosuppressive treatments given for the treatment of vasculitis, and the relationship with the infection were evaluated. Results: Seventy-four patients diagnosed with AAV were included in the study. Hospitalization due to infection was observed in 36 of the patients. The coexistence of diabetes mellitus (DM) was found to be significantly higher in the infected patient group. Cyclophosphamide (CYC) treatment found to increase risk of infection. More than 80% of the infected patient group presented with renal involvement (80.6%). A total of 68 infectious episodes were seen in 36 patients. The most common involvement of infection was the respiratory tract with a rate of 70.6%. Gram-negative bacteria were the most common pathogen, especially Pseudomonas aeruginosa. With the effect of the pandemic, SARS-CoV-2 has come to the fore among viral infections. Aspergillosis was the most frequently detected among fungal infections. Besides, aspergillosis was the cause of 85.7% (6 episodes) of fungal infections. Lymphopenia was observed in 76.5% of the infection episodes. 57.4% of infections developed in the first year of the induction therapy. The most frequently used immunosuppressive therapy for the treatment of vasculitis in infectious episodes was CYC (41.2%). Conclusion: Managing infections during the vasculitis treatment is crucially important. Lymphopenia, kidney involvement, DM and immunosuppressive therapy are factors that increase the risk of infection. Clinicians should take preventive measure especially for respiratory tract infections and gram-negative bacteria as pathogens.