LAUSR

Background: Infections are among the most serious complications in patients with aNCA-associated vasculitides (AAV) and contribute significantly in overall mortality. Objectives: To describe the incidence and risk factors for serious infections, as well as the patterns of cotrimoxazole prophylaxis in aAV patients (GPA and MPA). Methods: Retrospective, descriptive study of aAV patients followed in a tertiary referral center (Clinical Immunology-Rheumatology Unit and Nephrology department). Patient and disease characteristics treatments and serious infections were recorded. Results: 56 aAV patients were included (women: 50%, mean age at diagnosis: 59.8 years, mean disease duration: 5.1 years, GPA: 68%, generalized disease: 82%). Most frequent organ involvement was renal (71%), lung (68%), nervous (20%), skin (18%) and mucous membranes/eyes (14%). 21 serious infections were recorded in 16 patients (incidence: 7.2 per 100 patient-years), with respiratory tract infections (43%) and herpes zoster (19%) being the most frequent. Incidence was 6.2-times higher in patients with severe combined lung-kidney involvement compared to those without (20 vs 3.2 per 100 patient-years, p<0.001). Plasma exchange and/or hemodialysis (44% vs 12%, p=0.01), age >60 years (62% vs 35%) and treatment with cyclophosphamide (CYC)/rituximab (RTX) combination (38% vs 3%, p=0.001) were more common among those who developed a serious infection. Lung-kidney involvement and combined CYC/RTX treatment remained statistically significant in multivariate logistic regression analysis. Cotrimoxazole prophylaxis was given in 70% of patients treated with CYC and/or RTX (n=46). Patients with combined lung-kidney involvement were more likely to receive prophylaxis (82% vs 58%, p=0.08). No case of pneumocystis pneumonia was diagnosed during follow-up. Conclusion: In this real-life cohort, more than one out of four aAV patients experienced a serious infection during follow-up, with pneumonia and herpes zoster being the most frequent. Patients with combined lung and kidney involvement had a ∼6 times higher risk for developing a serious infections and were more likely to receive appropriate cotrimoxazole prophylaxis. Disclosure of interests: None declared