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 filtration rate (eGFR) at kidney biopsy and after 18 months. METHODS: This retrospective study enrolled 44 patients (43.2% male) with antineutrophil cytoplasmic antibodies-associated glomerulonephritis treated at the University Clinical Center of Vojvodina between 2017 and 2020. The numerical density of infiltrates in the tubulointerstitium 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 sclerosis 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 after 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 numerical density of infiltrates significantly correlated with eGFR at biopsy (r = -0.614), but not after 18 months. Our results 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.