Acute kidney injury in Chinese patients with lupus nephritis: a large cohort study from a single center

Objective In this study we assess clinicopathologic characteristics, treatment and prognosis of acute kidney injury (AKI) in a large cohort of Chinese patients with lupus nephritis. Methods The clinical, laboratory, renal histopathology, treatment and outcome data were retrospectively collected and compared between lupus nephritis patients with and without AKI. The impact of AKI on renal outcome was evaluated. Results Among 322 patients with renal biopsy-proven lupus nephritis, 66 (20.5%) were identified as AKI. Male predominance was observed in patients with AKI (p < 0.001). In comparison with the non-AKI group, patients with AKI had significantly higher proportions of serositis (p < 0.001), neurologic disorder (p = 0.026), anemia (p < 0.001), thrombocytopenia (p = 0.013) and nephrotic syndrome (p = 0.011), but significant lower serum C3 (p < 0.001). The Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, renal pathological activity indices and chronicity indices were significantly higher in the AKI group (p < 0.001 in all cases). Regarding outcome, the AKI group had a significantly poorer renal outcome compared with non-AKI group (p < 0.001). In the AKI group, patients with crescentic glomerulonephritis and thrombotic microangiopathy had the worst renal outcome. AKI was an independent risk factor for renal outcome (hazard ratio [HR] = 5.819, 95% confidence interval 2.411-14.044, p < 0.001). Conclusions AKI is common in lupus nephritis and is an independent risk factor for renal outcome.