High-risk features of lupus nephritis: importance of race and clinical and histological factors in 166 patients.

BACKGROUND The pleomorphic nature of lupus nephritis has confounded efforts to refine estimates of prognosis. Consideration of interactions among prognostic factors may help to identify high-risk patients. METHODS By univariate and multivariate survival analysis, race and attributes of severe active lupus nephritis were evaluated as potentially important prognostic factors in 166 patients upon entry into prospective therapeutic trials of lupus kidney disease. RESULTS Black patients were significantly more likely than others to develop renal insufficiency. Cellular crescents emerged as the most predictive active pathological feature and interstitial fibrosis was the strongest chronic histological prognostic factor. Combinations of these morphological attributes identified particularly high-risk individuals. Patients with 50% or more cellular crescents and those with less extensive cellular crescents plus moderate to severe interstitial fibrosis were at markedly increased risk for doubling serum creatinine compared to those who lacked these histologic features (P < 0.0001). Azotaemia, anaemia, hypocomplementaemia, hypertension, tubular atrophy and glomerular sclerosis were also associated with an increased probability of renal function deterioration. Serum creatinine, haematocrit, race, and kidney pathology data emerged as independent predictors of renal insufficiency. Black patients in this study were more likely than the others to have high-risk histological features, including extensive cellular crescents (> or = 50%) and moderate to severe interstitial fibrosis, prior to randomization. CONCLUSIONS Combinations of high-risk demographic, clinical and histological attributes identify patients at increased risk for progressive renal function deterioration. Several factors, including the severity of kidney biopsy findings, probably contribute to the poor prognosis of Black patients in this study population.