Clinicopathological Characteristics and Outcomes of Chinese Patients with Scanty Immune Deposits Lupus Nephritis: A Large Cohort Study from a Single Center

OBJECTIVE To assess clinicopathological characteristics of lupus nephritis patients with scanty immune deposits. METHODS The data of patients with scanty immune deposits lupus nephritis were retrospectively analyzed. Plasma ANCA and complement components were detected. RESULTS Among 316 cases with renal biopsy-proven lupus nephritis, 40 cases were diagnosed as scanty immune deposits. There were significantly higher value of serum creatinine (P = 0.002) and lower hemoglobin level (P = 0.009) and higher score of cellular crescents (P = 0.015) in scanty immune deposits group compared with immune complex deposits group. The frequency of positive plasma ANCA was significantly higher in scanty immune deposits group than that in immune complex deposits group (52.5% versus 10.1%, P < 0.001). As for comparisons of plasma complement components, there were significantly higher levels of C1q (P = 0.005) and Bb (P = 0.02) and lower level of factor H (P = 0.003) in scanty immune deposits group. The ratio of treatment failure was significantly higher in scanty immune deposits group than that in immune deposits group (42.5% versus 19.20%, P = 0.001). The renal outcomes were similar between the two groups. CONCLUSIONS Patients with scanty immune deposits lupus nephritis had more severe kidney damage. ANCA and activation of complement alternative pathway might be involved in the pathogenesis of the disease.