The relevance of periglomerular fibrosis in the evaluation of routine needle core renal biopsies.

CONTEXT: Renal interstitial fibrosis and, to a lesser extent, sclerotic glomeruli correlate with poor renal function. However, not all nonfunctional glomeruli are sclerotic. Many or most glomeruli with periglomerular fibrosis, while retaining blood flow, probably do not filter; therefore, they may not contribute to renal function. OBJECTIVE: To examine the relationship of periglomerular fibrosis and the sum of globally sclerotic glomeruli and glomeruli with periglomerular fibrosis (GSG+PF) with interstitial fibrosis and renal function. DESIGN: Native kidney biopsies from 177 patients with chronic renal injury were assessed for interstitial fibrosis, glomerular sclerosis, and GSG+PF. Renal biopsies with active or acute lesions were not included. The percentage of globally sclerotic glomeruli and GSG+PF was correlated with the degree of interstitial fibrosis and serum creatinine levels. RESULTS: The percentage of GSG+PF correlates better with the degree of interstitial fibrosis and renal function than does the percentage of globally sclerotic glomeruli alone. This appears particularly true in chronic renal diseases of patients without diabetes. The number of globally sclerotic glomeruli correlates better with interstitial fibrosis and renal function than does the sum of globally and segmentally sclerotic glomeruli. CONCLUSIONS: The percentage of GSG+PF in a renal biopsy specimen provides a better estimate of chronic renal injury than does the percentage of sclerotic glomeruli alone, probably because many or most glomeruli with periglomerular fibrosis are nonfunctional. Therefore, we recommend that the number of glomeruli with periglomerular fibrosis also be provided in the renal biopsy report.