Clinicopathological characteristics and outcomes of patients with ANCA-positive lupus nephritis: a large cohort study from a single Chinese center

Very limited clinicopathological and clinical outcome data are available regarding lupus nephritis (LN) patients with antineutrophil cytoplasmic antibodies (ANCAs). The present study therefore investigated such data in a large cohort of LN patients in China. 478 patients with renal biopsy-proven lupus nephritis diagnosed in The First Affiliated Hospital of Sun Yat-sen University from January 1998 to December 2011 were enrolled. The primary endpoint was the composite of a doubling of baseline serum creatinine, end-stage renal disease, or death. The prevalence of ANCA seropositivity in this cohort was 14.0% (67/478). At the time of biopsy, ANCA-positive patients had higher CRP levels, higher ESR values, and were more frequently positive for anti-cardiolipin antibodies. However, they had lower eGFR values, and lower levels of HDL-C, LDL-C, and hemoglobin when compared with ANCA-negative patients. ANCA-positive patients had a higher prevalence of 2003 ISN/RPS class IV LN, and higher scores for karyorrhexis/fibrinoid necrosis, cellular glomerular crescents, interstitial inflammation, and tubular atrophy. At a median follow-up time of 56 months (range, 3-162 months), the event-free survival rate for a composite outcome was significantly lower among patients with ANCAs than patients without (P = 0.015). Multivariate Cox regression analysis revealed that initial serum creatinine and CI score were the most important risk factors significantly affecting the primary outcome. Notably, ANCA was not independently associated with the primary outcome. Patients with ANCA-positive LN have more severe kidney injury and a worse long-term outcome compared with patients with ANCA-negative LN.