Academic Medical Center University of Amsterdam, The Netherlands; Columbia University, College of Physicians and Surgeons, New York, New York; Rush Medical College, Chicago, Illinois; Weill Medical College, Cornell University, New York, New York; University of Washington, Seattle, Washington; Columbia Presbyterian Medical Center, New York, New York; National Institutes of Health, Bethesda, Maryland; Leiden University Medical Center, Leiden, The Netherlands; Imperial College Medical School, London, United Kingdom; San Carlo Borromeo Hospital, Milan, Italy; Vanderbilt University, Nashville, Tennessee; SUNY Health Science Center, Brooklyn, New York; Ohio State University, Columbus, Ohio; Georges Pompidou European Hospital, Paris, France; St. Vincent's Hospital, Fitzroy, Victoria, Australia; University of North Carolina School of Medicine, Chapel Hill, North Carolina; University Kebangsaan Malaysia, Kuala Lumpur, Malaysia; Necker Hospital, Paris, France; Weill Medical College, Cornell University, New York, New York; University of Malaya Medical School, Kuala Lumpur, Malaysia; Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan; Federal University of Sao Paulo, Sao Paulo, Brazil; and University of Tsubuka, Ibaraki, Japan

Correspondence: Jan J. Weening M.D., Department of Pathology, Academic Medical Center University of Amsterdam, PO Box 22660, 1006 AZ Amsterdam, The Netherlands. E-mail:j.j.weening@amc.uva.nl

Received 13 October 2003; Revised 23 October 2003; Accepted 27 October 2003.

Abstract

The classification of glomerulonephritis in systemic lupus erythematosus revisited. The currently used classification reflects our understanding of the pathogenesis of the various forms of lupus nephritis, but clinicopathologic studies have revealed the need for improved categorization and terminology. Based on the 1982 classification published under the auspices of the World Health Organization (WHO) and subsequent clinicopathologic data, we propose that class I and II be used for purely mesangial involvement (I, mesangial immune deposits without mesangial hypercellularity; II, mesangial immune deposits with mesangial hypercellularity); class III for focal glomerulonephritis (involving <50% of total number of glomeruli) with subdivisions for active and sclerotic lesions; class IV for diffuse glomerulonephritis (involving 50% of total number of glomeruli) either with segmental (class IV-S) or global (class IV-G) involvement, and also with subdivisions for active and sclerotic lesions; class V for membranous lupus nephritis; and class VI for advanced sclerosing lesions. Combinations of membranous and proliferative glomerulonephritis (i.e., class III and V or class IV and V) should be reported individually in the diagnostic line. The diagnosis should also include entries for any concomitant vascular or tubulointerstitial lesions. One of the main advantages of the current revised classification is that it provides a clear and unequivocal description of the various lesions and classes of lupus nephritis, allowing a better standardization and lending a basis for further clinicopathologic studies. We hope that this revision, which evolved under the auspices of the International Society of Nephrology and the Renal Pathology Society, will contribute to further advancement of the WHO classification.