The outcome and a new ISN/RPS 2003 classification of lupus nephritis in Japanese

Background. A considerable diversity in prognosis is seen with lupus glomerulonephritis (LGN). Hence, the clinical usefulness of a recent International Society of Nephrology/ Renal Pathology Society (ISN/ RPS) 2003 classification to judge the long- term outcome of human LGN has been investigated. Methods. We studied retrospectively 60 subjects with LGN (7 males, 53 females, mean age of 33 years old) who underwent renal biopsies and were followed from 1 to 366 months, with a mean of 187 months. We diagnosed renal pathology as classes, active and sclerosing lesions, according to the new and WHO1995 classification of LGN, and analyzed the clinicopathologic factors affecting to the prognosis of LGN. Results. New classification got much higher consensus in the judgment of classes (98% vs. 83%, P = 0.0084). The group of Class IV- S (N = 6) or IV- G (N = 17) at initial biopsies showed higher rate of end- stage renal failure (ESRF) compared with that of Class I, II, III or V (40.9% vs. 2.6%, P < 0.001). The mean 50% renal survival time of Class IV was 189 +/- 29 months, and patients with Class IV- S tended to have a poorer prognosis (95 +/- 22 months for IV- S vs. 214 +/- 35 months for IV- G, P = 0.1495). Class IV was also selected as the most significant risk factor for ESRF by stepwise model (P = 0.002). In sub-analysis for ESRF in Class IV (- S or -G), treatment including methylprednisolone pulse therapy was only selected as a significant improving factor for primary outcome (P = 0.034). In addition, activity index was the significant risk factor of death and/ or ESRF after initial renal biopsies (P = 0.043). As for actuarial patient death during all follow- up periods, complications with anti-phospholipid syndrome or nephrotic syndrome were significant risk factors (P = 0.013, P = 0.041, respectively). Conclusion. New ISN/ RPS 2003 classification provided beneficial pathologic information relevant to the long- term renal outcome and the optimal therapy preventing ESRF and/ or death in patients with LGN.