Clinicopathologic Characteristics and Outcomes of Lupus Nephritis With Antineutrophil Cytoplasmic Antibody: A Retrospective Study

Abstract

Few studies have analyzed the clinicopathologic characteristics and outcomes of lupus nephritis (LN) patients with antineutrophil cytoplasmic antibody (ANCA). The clinical and renal histopathologic data of 154 patients with biopsy-proven LN from 2011 to 2013 were analyzed retrospectively. The patients were followed up for a median period of 16.8 ± 9.4 months, and their outcomes were analyzed. Multivariate Cox analysis was used to evaluate the independent factors for poor outcomes. Among the 154 LN patients, 26 (16.88%) were seropositive for ANCA. The incidences of alopecia, oral ulcer, photosensitivity and skin lesion, and psychosomatic manifestations in the ANCA-positive group were significantly higher than in the ANCA-negative group (P = 0.007, 0.02, 0.02, and 0.03, respectively). Compared with the ANCA-negative group, the ANCA-positive group had significantly lower levels of complement C3 (P = 0.03). Additionally, the positive rate of antinucleosome antibodies, antihistone antibodies, antimitochondrial antibody M2, and anticardiolipin antibodies were higher significantly in the ANCA-positive patients than in the ANCA-negative patients (P = 0.001, 0.001, 0.03, 0.005, respectively). The ANCA-positive group had a notably higher chronic index than the ANCA-negative group (P = 0.01). During the follow-up, the complete remission rate in the ANCA-negative group was higher than that in the ANCA-positive group (P = 0.01). The cumulative renal survival rate in the ANCA-positive group was significantly lower than in the ANCA-negative group (log-rank = 6.59, P = 0.01). Multivariate Cox analysis revealed that the reduced estimated glomerular filtration rate (HR, 1.02; 95% confidence interval, 1.01 to 1.03; P = 0.005), NLR (HR, 1.20; 95% confidence interval, 1.02 to 1.40; P = 0.03), and ANCA (HR, 3.37; 95% confidence interval, 1.12 to 10.09; P = 0.03) were independent risk factors for patients' renal survival after adjusting for age, sex, crescent formation, and glomerulosclerosis. The study found ANCA in LN patients is not rare, and patients with ANCA present with more severe clinicopathologic injuries. Thus, ANCA is an independent risk factor for poor renal outcomes in LN patients.

FIGURE 1

Flow diagram of the included patients. ANCA = antineutrophil cytoplasmic antibody; ESRD = end-stage renal disease; LN = lupus nephritis; SCr = serum creatinine.

FIGURE 2

Comparison of renal survival between LN patients with and without antineutrophil cytoplasmic antibody (ANCA). Kaplan–Meier analysis was used to calculate the renal cum survivals in ANCA-positive and ANCA-negative groups, and the rates were 71.26% and 91.48%, respectively. The renal survival rate in the ANCA-positive group was significantly lower than that in the ANCA-negative group (log-rank = 6.59, P = 0.01). ANCA = antineutrophil cytoplasmic antibody; LN = lupus nephritis.