Prognostic Utility of the MEST-C Score Combined With Clinical Parameters in Hispanic Patients With IgA Nephropathy

Introduction: The Oxford/MEST-C classification is a histopathological scoring system for patients with IgA nephropathy (IgAN) that has demonstrated prognostic utility. The aim of this study was to evaluate the prognostic utility of the combination of clinical characteristics and MEST-C in Hispanic ethnicity patients. Methods: Retrospective cohort study. Clinical, laboratory, and kidney biopsy information with MEST-C classification was obtained. The primary outcome was the development of end-stage kidney disease (ESKD). Cox regression analysis was performed for factors associated with ESKD, and Kaplan-Meier survival analysis for kidney survival. Results: A total of 397 patients were included, 51% were male, median age was 38 years with an interquartile range (IQR) of 28-53. The main comorbidity was hypertension present in 60.5%. At the time of biopsy, estimated glomerular filtration rate (eGFR) was 54 mL/min (IQR 33-94) and 24 h proteinuria was 1680 mg (IQR 594-3500). 30.7% of patients developed ESKD over a median follow-up of 1702 days (IQR 808-2858). Multivariate analysis of M, E, S, T, and C lesions showed that only S and T lesions correlated with the development of ESKD. The combination of S and T items of the MEST-C score with variables such as age, eGFR, proteinuria, and hypertension were significantly associated with the outcome. Explored prognostic models showed a high Harrel's C concordance index of 0.89. Conclusion: Performing the MEST score, especially the presence of sclerosing (S) and tubular fibrosis/atrophy (T) lesions combined with clinical variables are prognostic variables in the Hispanic population.