Clinical characteristics and risk factors of antineutrophil cytoplasmic antibody-associated vasculitis complicated with infection / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the characteristics and risk factors of infection in newly diagnosed patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).Methods:The clinical data of AAV patients (followed up for at least 6 months) in Affiliated Hospital of Qingdao University from September 2012 to September 2020 were retrospectively collected. According to whether infection occurred during follow-up, the patients were divided into infection group and non-infection group. The clinical characteristics and infection status of the two groups were analyzed, and the Cox regression analysis model was used to explore the influencing factors of infection.Results:A total of 236 AAV patients were enrolled in this study, including 128 females (54.2%) and 108 males (45.8%), with a median age of 66.00 (59.76, 71.99) years. There were 202 patients (85.6%) with positive myeloperoxidase (MPO)-ANCA and 34 patients (14.4%) with positive protease 3 (PR3) -ANCA. There were 77 cases in the infection group and 159 cases in the non-infection group. A total of 121 infections occurred in 77 patients, and 54 infections (44.6%) occurred within 6 months after initial diagnosis. In the infection group the proportion of patients with hypertension history, pulmonary underlying diseases and patients who received hormone pulse therapy or plasma exchange, the incidence of lung, kidney, heart and gastrointestinal involvement, the level of serum creatinine and five factors score (FFS) at initial diagnosis were significantly higher than those in the non-infection group (all P<0.05), while the estimated glomerular filtration rate (eGFR) was significantly lower ( P<0.05). Lung (73.6%) was the main infection organ of AAV patients. The most common pathogenic microorganisms were bacteria (64.0%), mainly Pseudomonas aeruginosa and Staphylococcus aureus, followed by fungi (33.7%, mainly Candida albicans). Multivariate Cox regression analysis showed that lung involvement ( HR=1.682, 95% CI 1.034-2.734, P=0.036) and gastrointestinal involvement ( HR=2.976, 95% CI 1.219-7.267, P=0.017) were the independent influencing factors for infection in AAV patients. Conclusions:AAV patients have a higher incidence of infection within 6 months after initial diagnosis. The most common organ of infection in AAV patients is the lung, and the common pathogens are Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Lung involvement and gastrointestinal involvement are the independent risk factors for infection in AAV patients.