Histopathological and Immunofluorescence Findings on Kidney Biopsies in Patients with Crescentic Glomerulonephritis

Abstract

Background: Regional variations in crescentic glomerulonephritis (CresGN) presentation and etiology are reported while accurate data is needed to guide healthcare planning, screening, diagnosis, and treatment.

Objective: This study aimed to characterize histopathological and immunofluorescence findings in kidney biopsies of patients with CresGN.

Methods: A descriptive cross-sectional study was conducted in the Department of Histopathology at the Sindh Institute of Urology and Transplantation (SIUT), Karachi, Pakistan, from April 15, 2023 to October 14, 2023. Convenience sampling was used to enroll 60 eligible adults diagnosed with CresGN. Biopsy specimens were processed into paraffin blocks, sectioned, stained, and analyzed using immunofluorescence. Descriptive statistics summarized categorical variables, including types of crescents, laboratory findings, and histopathological and immunofluorescence outcomes.

Results A total of 60 biopsy specimens were observed. Based on the histopathological findings, most of the patients had two cores (n=48, 80%) with a mean length of 0.7± 0.24 cm. The mean number of glomeruli was 14±5 (ranging from 7 to 21). The most common crescent type was cellular (n=24, 40%). 55 out of 60 patients had negative antibodies along with C3 and C1q. However, five patients showed weak focal positivity for IgG and IgM antibodies along with similar reactivity for C3 and C1q. The pauci-immune group was the most common type of CresGN. According to Berden classification, the majority (n=25; 41.7%) belonged to a crescentic category.

Conclusion: Pauci-immune CresGN was the predominant subtype, with cellular crescents as the most frequent histopathological finding. These results emphasize the importance of detailed immunofluorescence and histological evaluation ..............