Renal Amyloidosis: An Approach to Uniform Biopsy Reporting

Renal amyloidosis results in progressive renal failure, and consistent biopsy reporting improves prognostic accuracy and permits interinstitutional comparisons.

This study aims to apply the histopathologic classification of Sen and Sarsik, calculate the Renal Amyloid Prognostic Score (RAPS), and correlate histological grade with clinical severity.

We retrospectively analyzed 18 biopsy-proven cases of renal amyloidosis out of 1,008 native renal biopsies performed at IMS & SUM Hospital, Siksha 'O' Anusandhan (Deemed University), Bhubaneswar, Odisha, India, between January 2021 and January 2026. Glomerular amyloid pattern (GAP) classes I-VI, RAPS, and final histologic grade (0-3) were assigned. Clinical data included age, sex, 24-hour protein, urea, creatinine, and underlying diagnosis. Statistical analyses used independent t tests, Fisher's exact test, and Spearman correlation.

The prevalence was 1.78%. The majority were primary amyloid light chain (AL) (12/18). Glomerular deposition was universal, with GAP class IV (15/18) predominating, associated with Grade 3. Grade 3 had significantly higher 24-hour proteinuria and serum creatinine than Grade 2 (P = 0.006 and P = 0.042). RAPS correlated positively with proteinuria (r = 0.68, P < 0.01) and creatinine (r = 0.59, P < 0.05).  Conclusions: RAPS and histologic grading provide a consistent evaluation of renal amyloid burden, correlating with clinical severity. Prompt biopsies and standardized reporting can inform prognosis and guide treatment.