Prognostic significance of tubulointerstitial macrophage density in MPO-ANCA-associated glomerulonephritis: implications for renal outcomes.

Abstract

This study aimed to evaluate the density of tubulointerstitial macrophages with renal outcomes in patients with myeloperoxidase-anti-neutrophil cytoplasmic antibody associated glomerulonephritis (MPO-ANCA-associated GN). This study analysed patients with MPO-ANCA-associated GN who had renal biopsies at Jinling Hospital. It looked at the density of CD68+ macrophages in the tubulointerstitium and examined correlations with serum creatinine levels, urinary protein levels, treatment regimen and renal histologic class. The study used KM curves to show the impact of these factors on renal prognosis and conducted multivariate analyses with Cox proportional hazards regression models. A total of 172 patients with MPO-ANCA-associated GN (median age: 50 y, 43.6% male) were included. Stratification of the cohort into tertiles was based on tubulointerstitial macrophage density. Significant differences in serum creatinine levels, induction treatment regimen, the rates of end-stage kidney disease, and renal histologic class were observed between the three groups. Correlation analysis showed that induction treatment regimen and renal histologic class were correlated with tubulointerstitial macrophage density. Kaplan-Meier curves illustrated patients with a lower presence of CD68+ macrophages in the tubulointerstitium experienced significantly better renal survival compared with those with a higher presence. The higher levels of CD68+ macrophage infiltration were significantly associated with adverse renal outcomes. This association persisted after adjusting for potential confounders including baseline serum creatinine, histopathological class, and induction therapy modalities. The results of our study provide insight into the prognostic significance of macrophage infiltration in the tubulointerstitium in MPO-ANCA-associated GN.