Importance of numerical density of tubulointerstitium infiltrates in the prognosis of antineutrophil cytoplasmic antibodies-associated glomerulonephritis

Aim To examine the association of the numerical density of the tubulointerstitium infiltrate with pathohistological changes in the glomeruli and the estimated glomerular fil-tration rate (eGFR) at kidney biopsy and after 18 months. Methods This retrospective study enrolled 44 patients (43.2% male) with antineutrophil cytoplasmic antibod-ies-associated glomerulonephritis treated at the Univer-sity Clinical Center of Vojvodina between 2017 and 2020. The numerical density of infiltrates in the tubulointersti-tium was determined with the Weibel (M-2) system. Data on biochemical, clinical, and pathohistological parameters were obtained. Results The mean age was 57.7 +/- 10.23 years. Global scle-rosis in more than 50% of glomeruli and crescents in more than 50% of glomeruli were significantly associated with a mean lower eGFR (17.6 +/- 11.78; 32.0 +/- 26.13, respectively) at kidney biopsy (P = 0.002; P < 0.001, respectively), but not af-ter 18 months. The average numerical density of infiltrates was significantly higher in patients with more than 50% of globally sclerotic glomeruli (P < 0.001) and with crescents in more than 50% of glomeruli (P < 0.001). The average nu-merical density of infiltrates significantly correlated with eGFR at biopsy (r =-0.614), but not after 18 months. Our re-sults were confirmed by using multiple linear regression. Conclusion Numerical density of infiltrates, and global glomerular sclerosis and crescents in more than 50% of glomeruli significantly affect eGFR at biopsy, but not after 18 months.