Renal histopathology and clinical course in 94 patients with Wegener's granulomatosis

Background. The main purpose of this study was to examine histopathological changes seen in renal biopsies from patients with Wegener's granulomatosis (WG) with varying degrees of renal involvement and to study possible corre lations between the morphological variables and the severity of the disease . Methods. Ninety-four patients with WG and active renal disease were include d in this retrospective study. All patients had a percutaneous renal biopsy taken on their first admission to the hospital and 14 patients had a secon d biopsy. The patients were followed for a median of 42.5 months (range 0.5 -184). Results, Segmental necrotizing glomerulonephritis and extracapillary prolif eration were present in 85.1 and 91.5% respectively. Of seven patients (7.4 %) with normal serum creatinine and urinary protein excretion <0.5 g/day, a ll had crescents and six had segmental glomerular necrosis. Serum creatinin e at biopsy correlated significantly with the percentage of glomeruli with crescents (<rho> = 0.2, P = 0.8004), with necrosis (rho = 0.36, P = 0.002) and with the percentage of normal glomeruli (rho = -0.55, P = 0.0003). On a multivariate analysis, only the percentage of normal glomeruli was signifi cantly associated with renal function and development of end-stage renal di sease. In 14 second biopsies after a mean of 41.2 (+/- 26) months, chronici ty scores had increased significantly in 13 biopsies in spite of full immun osuppressive treatment. Conclusion, Although renal biopsy is of value in de fining renal involvement in WG, it is of limited help in the early stage of the disease in predicting renal outcome for the individual patient. a foll ow-up biopsy can be useful in revealing the degree of activity and chronici ty and hence be of importance for the choice of further therapy.