Classification of lupus nephritis

Purpose of review Lupus nephritis manifests as diverse patterns of immune complex-mediated renal disease affecting glomerular, tubulointerstitial, and vascular compartments. This review will focus on the most recent classification, the 'International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003 Classification of Lupus Nephritis', and will briefly discuss other types of renal disease seen in patients with systemic lupus erythematosus. Recent findings The ISN/RPS 2003 Classification of lupus nephritis includes multiple changes from its predecessors, most notably removal of the subclasses of lupus nephritis class V (i.e. Va-Vd), elimination of the normal category (WHO class I), clearer definitions for all classes, a standard approach to sclerotic glomeruli, and the division of lupus nephritis class IV into subcategories based on whether the endocapillary involvement is predominantly segmental (lupus nephritis IV-S) or global (lupus nephritis IV-G). These changes have led to a higher level of interobserver reproducibility and a significant increase in the number of cases of class IV, with a reciprocal decline in lupus nephritis class III and lupus nephritis class V. Multiple studies have found that lupus nephritis class IV-S has similar or better outcomes than lupus nephritis class IV-G. Summary The ISN/RPS 2003 classification of lupus nephritis is gaining widespread acceptance and appears to be achieving its goals of reproducibility and clinical relevance.