Of 500 patients with systemic lupus erythematosus observed at our center, 150 fulfilled criteria for lupus nephritis. Of these 150 patients, 91% were female, and 67% were white. The mean age of onset was 26.2 years, and the mean follow-up duration was 11.7 years. Biopsies (n = 142) performed on 107 patients showed the following World Health Organization (WHO) class distribution: class I, n = 1; class II, n = 13; class III, n = 19; class IV, n = 69; class V, n = 17; class VI, n = 8; and class not determinable, n = 15. Ninety-five patients were nephrotic. Therapeutic intervention courses given to all patients (n = 356) included parenteral (IV) cyclophosphamide (n = 58), high-dose oral steroids (n = 126), pulse steroids (n = 49), apheresis (n = 39), azathioprine (n = 43), oral cyclophosphamide (n = 5), nitrogen mustard (n = 27), and chlorambucil (n = 6). In addition to examining the course of disease for various subsets, various predictors for fatality and end-stage renal disease (ESRD) were analyzed. Descriptive data for the short-term response to five therapies are provided for the complete patient sample, proliferative disease, and nephrotic syndrome. Twenty patients died, primarily from cardiovascular complications and sepsis, with 97% and 92% 5- and 10-year survival rates, respectively. Twenty-nine were dialyzed, and 11 were transplanted. Risk of ESRD by WHO class at 5 years was as follows: class III, 0%; IV, 9%; V, 16% (P = .04 for class V v other patterns).(ABSTRACT TRUNCATED AT 250 WORDS)