Risk Factors for Renal Failure in Patients with Lupus Nephritis: Data from the Spanish Registry of Glomerulonephritis

BACKGROUND: Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus. Data from national registries based on renal biopsies are scarce. The aim of our study was to analyze the demographic characteristics, clinicopathological correlations, and risk factors associated with renal failure in patients with LN at the time of renal biopsy. METHODS: We performed a cross-sectional observational study based on data from the Spanish Registry of Glomerulonephritis for the years 1994–2009. The outcome measure was the presence of renal failure (eGFR <60 ml/min/1.73 m(2)). We also recorded age, gender, proteinuria levels, hypertension, and histological class. RESULTS: We collected 17,525 native renal biopsies, of which 1,648 biopsies showed LN lesions. In total, 609 patients (37%) showed renal failure at the time of renal biopsy. The univariate analysis showed that these patients were older, had higher levels of proteinuria, and a higher prevalence of hypertension than the group with eGFR ≥60 ml/min/ 1.73 m(2). The histological class of LN was recorded for 566 patients, and multivariate logistic regression analysis showed that the independent risk factors for renal failure at the time of renal biopsy were age (OR 1.03; 95% CI 1.01–1.04), male gender (OR 1.94; 95% CI 1.12–3.10), hypertension (OR 3.18; 95% CI 2.16–4.67), proteinuria (OR 1.15; 95% CI 1.08–1.24), and histological classes III and IV (OR 1.82; 95% CI 1.16–2.87). CONCLUSIONS: Data from the Spanish Registry of Glomerulonephritis provide valuable information about risk factors for renal failure in patients with LN at the time of renal biopsy.