Serial renal biopsy in systemic lupus erythematosus.

Objective. To examine the role of sequential renal biopsies in patients with systemic lupus erythematosus (SLE), with regard to indications, morphologic change over time, and the clinical utility of repeat biopsies. Methods. Patients with repeat renal biopsies were identified from the University of Toronto Lupus Clinic Database and their biopsies were reviewed blindly by a committee, using the WHO classification as well as activity and chronicity indices. Reasons for obtaining biopsy were documented, and therapeutic decisions following repeat biopsy were tabulated. Results. Fifty-seven patients (49 F/9 M) had at least 2 renal biopsies between 1970 and 1994. The mean interval between biopsies was 4.2 years. The major reason for obtaining the first biopsy was disease diagnosis (32/57), while the majority of repeat biopsies were performed to discern the cause of increasing proteinuria (45/57). A comparison of the WHO classification of initial and repeat biopsies showed evolution to another class in 23 instances, but more commonly a change within a class was seen. A decrease in proliferative lesions (classes III and IV and subsets of V) was noted on repeat biopsies. The chronicity index increased significantly (p = 0.0001) and the activity index decreased (p = 0.064) between biopsies. Seventy-seven percent of patients had a change in treatment based on biopsy results. Conclusion. The major reason for repeat renal biopsy in patients with SLE was proteinuria. Renal morphology in patients with SLE can change with time, particularly in terms of chronicity and activity features. Repeat biopsies in patients with SLE appear to have clinical utility.