Global glomerulosclerosis proportions predict nephropathy progression in IgA nephropathy: a multicenter retrospective analysis with propensity score matching.

Background: Immunoglobulin A nephropathy (IgAN) is the most common primary glomerular disease worldwide. The role of global glomerulosclerosis (GS) in the patients with IgAN remains controversial. The study aims to evaluate the effect of GS on the kidney outcome in the patients with IgAN.

Methods: Based on the median of GS proportion, patients were divided into two groups (GS1 and GS2). Thereafter, the clinical, demographic, and treatment characteristics were evaluated by propensity score matching, Kaplan-Meier survival curves, Cox regression analyses. Next, the receiver operating characteristic curve analysis, continuous net reclassification improvement and integrated discrimination improvement were constructed to assess whether the model contained GS proportion could refine risk prediction and clinical utility.

Results: In this three-center retrospective study, a total of 1,626 IgAN patients were recruited. Both in the full and matched cohort, higher GS proportions were found to be independent prognostic factors for the kidney survival via Kaplan-Meier analysis (p < 0.05, p < 0.05, respectively). Additionally, the multivariate Cox regression models identified higher proteinuria, decreased eGFR, higher score of tubular atrophy/interstitial fibrosis (T), higher GS proportions as independent prognostic factors for poor kidney outcomes, and corticosteroids therapy was a protective indicator of kidney outcomes. Lastly, the prediction model based on these prognostic factors were validated to be accurately predict the kidney outcome when including GS proportions.

Conclusions: GS proportions are independent predictors for poor prognosis in IgAN patients.