Risk factors in idiopathic renal vasculitis and glomerulonephritis

In this retrospective study, we analyzed clinical laboratory, and pathologic variables to determine their value in predicting survival and survival free of renal failure for 170 consecutive patients with idiopathic renal vasculitis and glomerulonephritis evaluated during a 15 year period. Of the 170 patients, 108 had focal segmental necrotizing glomerulonephritis alone (FSNGN), 33 had FSNGN and small-artery vasculitis, and 29 had FSNGN and medium-sized artery vasculitis. Considerable overlap of clinical, laboratory, and pathologic findings existed among the three groups. Overall patient survival was 81% at one year, 61% at five years, and 44% at ten years, significantly less than expected survival. Overall survival free of renal failure, by definition, was lower than patient survival. There were no differences among these three groups in patient survival or survival free of renal failure. Multivariate analysis identified leukocytosis and serum creatinine level as independent predictors of patient survival and survival free of renal failure. In addition, univariate analysis identified age and hypertension as significant risk factors but did not add independent predictive value for these two end points. In patients with serum creatinine levels less than 4 mg/dl, the effect of increasing levels of leukocyte count was significantly associated with poorer outcomes for both patient survival (P = 0.006) and survival free of renal failure (P = 0.024). Outcomes for these two end points were worse for patients with lower serum creatinine levels (less than 4.0 mg/dl) and high leukocyte counts (greater than 16,000/mm3) than for those with serum creatinine levels greater than or equal to 4.0 mg/dl.