Correlation of percentage of normal glomeruli with renal outcome in Wegener's granulomatosis

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.