The difference between lupus nephritis class IV-G and IV-S in Koreans: focus on the response to cyclophosphamide induction treatment.

OBJECTIVES To evaluate the response to induction therapy with intravenous (i.v.) cyclophosphamide (CYC) in Korean patients with class IV-G (diffuse global proliferative glomerulonephritis) and class IV-S (diffuse segmental proliferative glomerulonephritis) lupus nephritis (LN) according to the classification system of the International Society of Nephrology/Renal Pathology Society (ISN/RPS). METHODS Of the 52 patients with biopsy-proven diffuse proliferative LN, who had been treated with i.v. CYC over a 10-yr period, 42 had been treated with i.v. CYC (equal to or more than 500 mg) for 6 consecutive months and had biopsy specimens containing more than nine glomeruli. The renal pathology of these 42 patients was reclassified according to the International Society of Nephrology and the Renal Pathology Society 2003 classification, and their renal response rates and laboratory indices after induction therapy were analysed. RESULTS Of the 42 patients assessed, 30 (71%) had IV-G and 12 (29%) had IV-S. Pre-treatment 24 h urinary protein was significantly higher and pre-treatment concentration of anti-dsDNA antibody was significantly lower in IV-G than in IV-S patients. Following induction therapy, complete remission rates were significantly higher in patients with IV-S (67%, 8/12) than in patients with IV-G (33%, 10/30) LN. CONCLUSIONS Class IV-G LN responded more poorly to induction therapy with i.v. CYC pulse than class IV-S LN.