Prognostic factors in lupus nephritis: diagnostic and therapeutic delay increases the risk of terminal renal failure.

OBJECTIVE: To evaluate the prognostic significance of clinical and renal biopsy findings in an unselected cohort of patients with systemic lupus erythematosus (SLE) and nephritis. METHODS: Ninety-one patients with lupus nephritis were included in the study. Renal biopsies were classified according to the WHO criteria and examined for the presence of active and chronic histological changes. Predictors of endstage renal disease (ESRD) were identified by univariate and multivariate analyses. RESULTS: The median followup time was 6.1 years (0.1-30.0 yrs). In all cases, immunosuppressive treatment was initiated or intensified within one month following renal biopsy. The cumulative incidence of ESRD after 1, 5, and 10 years was 3.5%, 15%, and 17%, respectively. A variety of clinical and biopsy findings including several histological markers of chronic renal damage were identified as univariate predictors of ESRD. In multivariate regression analyses, duration of nephritis symptoms > 6 months prior to biopsy, s-creatinine > 140 micromol/l, diffuse proliferative glomerulonephritis, and tubular atrophy emerged as the strongest combination of independent risk factors (relative hazard ratios: 9.3, 5.6, 8.9, and 3.1, respectively). CONCLUSION: Our results confirm the negative prognostic impact of hypercreatininemia, class IV histopathology, and tubular atrophy in lupus nephritis. Our data show that delay between onset of nephritis and renal biopsy constitutes an important risk factor of ESRD. Patients with SLE should have kidney biopsy as soon as clinical signs of nephritis are evident in order to accelerate treatment decisions and minimize risk of inflammation-induced irreversible kidney damage.