ANTICARDIOLIPIN ANTIBODIES AS A RISK FACTOR FOR RENAL RELAPSE IN PATIENTS WITH SYSTEMIC LUPUS ERITHEMATOSUS

Background: Previous reports suggest that antiphospholipid antibodies and antiphospholipid nephropathy are associated with worse prognostic in lupus nephritis patients.Objectives: To determine the role of anticardiolipin antibodies (aCL) as risk factor for renal relapse in patients with systemic lupus erithematosus (SLE) and diffuse proliferative glomerulonephritis (DPGN) after complete remission with IV ciclophosphamide therapy.Methods: We carried out a prospective study of SLE patients (ACR criteria, 1982) with DPGN (WHO class IV) and complete remission (normal creatinine levels, urianalysis, and creatinine clearance) after 2 years of treatment with IV ciclophosphamide therapy (0.5-1 g/m BS per dose: 6 monthly, 3 bimonthly and 4 every three months). After 1 year follow-up, we divided patients in two groups: with (group I) and without (group II) renal relapse. Clinical (SLEDAI score, high blood pressure), biochemical (creatinine, 24 hours albuminuria, urinary sediment) and immunological (complement C3 and C4, antinuclear antibodies (ANA), anti-dsDNA antibodies and aCL IgG and IgM isotypes) variables were included for the analysis. Renal relapse was classified as nephritic or proteinuric (Hachmi et al, Lupus 2003). Statistical analysis was done using χ2 test, bivariate analysis, Cox regression model and Kaplan-Meier survival curves.Results: We included 48 patients (24 in each group), 39 women; median age 31 years, mean disease duration 6.8 years. Group I showed 12 nephrotic and 12 nephritic relapses. The mean SLEDAI score was 25.1±11.5 in group I vs 8.9±8.0 in group II (p=0.003). Bivariate analysis showed that renal relapse (group I) was strongly associated with lower C3 levels (p=0.02), higher ANA titers (p=0.01), higher SLEDAI score (p=0.003) and higher aCL IgM titers (p=0.01). However, Cox regression model demonstrated that ANA titers (OR 2.3, IC95% 1.1-5.6, p=0.05) and aCL titers IgM isotype (OR 2.6, IC95% 1.9-3.4, p=0.01), were the only risk factors associated with renal relapse.Conclusion: These results suggest that aCL IgM isotype in SLE patients with DPGN could be considered as a risk factor for renal relapse.Citation: Ann Rheum Dis, volume 65, supplement II, year 2006, page 377Session: Vasculitis