Course of renal pathology in patients with systemic lupus erythematosus.

Evaluation of the course of lupus nephropathy by serial kidney biopsy in 50 patients revealed a complex pattern of transitions from one histologic class to another. A high rate of transformations (56 percent) was observed, with fewer than half the patients remaining in the original category. Although the general trend was towards transformation to a less severe lesion (WHO classes III and IV transforming into classes II and V), this was certainly not the rule for all individual classes. These transformations were rarely predictable on the basis of available clinical, laboratory, or pathologic information, and were less common in younger patients. These results help clarify the pathologic behavior of lupus nephropathy in the modern therapeutic era and highlight the value of pathologic examination for the planning and evaluation of therapy in selected patients.