Factors associated with renal involvement in adult immunoglobulin A vasculitis: what is it?

The objective of this study is to examine the potential of specific parameters in determining renal involvement in adult patients diagnosed with Immunoglobulin A vasculitis (IgAV). The patients’ records with IgAV meeting the EULAR/PRINTO/PRES classification criteria who were diagnosed between January 2017 and January 2022 were retrospectively reviewed. The Birmingham Vasculitis Activity Score (BVAS) version 3 was used to assess initial disease activity. A comparison was conducted between the data of patients with and without renal involvement. To investigate factors associated with renal involvement, the significant parameters were used to develop a forward stepwise multivariate regression model. Receiver Operating Characteristic (ROC) curve analysis was used to evaluate the predictive ability of significant parameters for renal involvement. The study included 85 patients, of whom 22 (25.9%) had renal involvement. Patients with renal involvement had a median age of 60.5 years and a median follow-up of 56.3 months. The median BVAS and ferritin/albumin ratio (FAR) values were significantly higher in patients with renal involvement (<i>p</i> &lt; 0.001). Multivariate regression analysis identified initial BVAS and FAR values as factors associated with renal involvement. ROC analysis demonstrated that the initial BVAS and FAR values were associated with renal involvement, with AUCs of 0.882 and 0.817, respectively (<i>p</i> &lt; 0.001). The initial BVAS above 7.5, and baseline FAR above 24.97 are factors associated with renal involvement. The results of this study may provide the basis for identifying individuals at high risk for renal involvement and, consequently, for more rigorous monitoring.