Predictors of relapse in granulomatosis with polyangiitis: a multi-center study

Background Granulomatosis with polyangiitis (GPA) is a rare systemic vasculitis. Its severity ranges from indolent disease to fulminant that may cause death. With treatment, remission is seen in more than 80% of cases, although relapse is still common. There have been studies showing that there may be factors to predict relapse in GPA. Based on relapses, the decision to start treatment and/or to monitor the patients more closely is made. Therefore, predicting the relapse of GPA can be effective in controlling the disease. Our aim was to investigate possible factors for relapse in GPA. We recruited 254 patients diagnosed with GPA who were under treatment at Alzahra hospital affiliated to Isfahan University of Medical Sciences (from 2013 to 2020) and Amir Alam Hospital affiliated to Tehran University of Medical Sciences (from 2020 to 2022) to plan a retrospective study. Chi-squared or Fisher's exact tests were performed to compare categorical variables, while the Mann-Whitney U test was used to compare continuous variables. Results Analysis of our patients (aged 20-80,122 females) showed that 147 patients (57.9%) experienced relapse. Mean age in relapse group was 43.8 +/- 16.6 and in no-relapse group was 45.6 +/- 15.1 (P > 0.05). Among many potential predictors, we observed in multivariate analysis that positive PR3-ANCA (proteinase 3-antineutrophilic cytoplasmic antibodies) (P = 0.007, OR:2.62,CI:1.29-5.31),nose manifestations (P = 0.004, OR 3.00, CI 1.43-6.26), mucosal membranes involvement (P = 0.009, OR 4.21, CI 1.43-12.38), and gastrointestinal tract (GI) complications (P = 0.03, OR 5.64, CI 1.14-27.90) were significant predictors of GPA relapse. Conclusion Among clinical and laboratory features we studied, positive PR3-ANCA, nose manifestations, mucosal membranes involvement, and GI complications were independent predictors of relapse in patients with GPA.