Correlation of Percentage of Normal Glomeruli with Renal Outcome in Wegener’s Granulomatosis

Abstract

Background/Aims: We examined the correlations between renal biopsy findings in Wegener’s granulomatosis and renal function at baseline and 1 year in 22 patients who presented between 1988 and 1999. Methods: Renal histology was independently reviewed by 2 pathologists who were masked to the clinical data. The primary outcome was the relationship of the percentage of normal glomeruli to reciprocal serum creatinine at baseline and 1 year. Other histologic data were collected using a series of ordinal rating scales. Acute and chronic sum scores were calculated. Results: The median serum creatinine (SCr) at baseline was 3.9 mg/dl (0.8–14 mg/dl). Seven patients initially required hemodialysis, of whom 4 subsequently regained independent renal function. By 1 year of follow-up, the median (SCr) for patients with independent renal function was 1.9 mg/dl (0.9–6.8 mg/dl). Reciprocal SCr at baseline correlated with the percentage of normal glomeruli (r = 0.584, p = 0.005), crescent score (r = –0.595, p = 0.003), interstitial fibrosis as a percentage of cortical surface area (r = –0.669, p = 0.002), interstitial inflammation (r = –0.439, p = 0.041), eosinophil (r = –0.495, p = 0.019), neutrophil score (r = –0.557, p = 0.005), and acute sum score (r = –0.499, p = 0.018). However, only the percentage of normal glomeruli (r = 0.493, p = 0.023), the crescent score (r = –0.452, p = 0.035), and interstitial fibrosis as a percentage of cortical surface area (r = –0.466, p = 0.052) correlated with reciprocal SCr at 1 year of follow-up. Conclusion: In this relatively small data set, the percentage of normal glomeruli, the crescent score, and interstitial fibrosis as a percentage of cortical surface area correlated with renal function at both baseline and 1 year of follow-up.