THU0323 Subsettting Proliferative Lupus Nephritis According to the ISN/RPS Classification Does not Provide Valuable Prognostic Information

Objectives To evaluate, including through repeated renal biopsy, whether the different ISN/RPS classes of proliferative lupus nephritis (LN) have similar short- and long-term responses to immunosuppression and have distinct long-term prognosis. Methods Ninety-eight patients with new onset ISN/RPS proliferative (III, IV-S or IV-G) LN were diagnosed in our institution between 2001 and 2011. Their baseline renal parameters and their primary response to immunosuppressive therapy were compared, based on quarterly collected data during the first year. Long-term followup (mean 76 months) was also available, as well as repeated renal biopsy data, performed in 45 patients after a mean period of 30 months. Activity (range 0-42) and chronicity (range 0-6) indices were computed according to the Morel-Maroger scoring system. Results While baseline mean 24-h proteinuria was higher in Class IV-G patients (n=50) compared to Class III (n=25) and Class IV-S (n=23) and while baseline mean activity index was lower in Class III versus Class IV-S and Class IV-G, serum creatinine, serum albumin and 24-h proteinuria improved similarly over the first year in the 3 pathological classes. Morover, biochemical data collected at last followup did not differ, nor did the activity/chronicity index on repeated renal biopsy, nor the rate of end-stage renal disease or death. Percentages of patients treated with cyclophosphamide, mycophenolate mofetil and azathioprine were similar in the 3 pathological groups. Conclusions Long-term clinical and pathological prognosis of new-onset proliferative LN, can not be predicted by baseline subsetting according to the ISN/RPS classification. Disclosure of Interest None Declared