Risk Factors for Renal Survival in Chinese Patients with Myeloperoxidase-ANCA-Associated GN

Background And Objectives: Our study explored the association of histopathologic classification of ANCA-associated GN with renal survival in Chinese patients with myeloperoxidase-ANCA-associated GN.

Design, Setting, Participants, & Measurements: Two hundred fifteen patients with biopsy-proven myeloperoxidase-ANCA-associated GN were included from January of 1996 to December of 2014. The biopsies included focal (=27), mixed (=82), crescentic (=47), and sclerotic (=59) classes. The long-term renal outcome and risk factors of myeloperoxidase-ANCA-associated GN for different histopathologic classes were retrospectively analyzed.

Results: During a median follow-up time of 22 (9-51) months, 88 (40.9%) patients reached ESRD. The 5-year renal survival (overall 58.7%) was highest in the focal class (100.0%) and lowest in the sclerotic class (20.7%), with no difference between the mixed (58.9%) and crescentic (67.4%) classes. Patients in the mixed (hazard ratio, 0.34; 95% confidence interval, 0.20 to 0.57; <0.001) and crescentic (hazard ratio, 0.31; 95% confidence interval, 0.16 to 0.59; <0.001) classes were at lower risk for ESRD compared with patients in the sclerotic class, as were patients who received glucocorticoids plus mycophenolate mofetil (hazard ratio, 0.32; 95% confidence interval, 0.18 to 0.60; <0.001) compared with those receiving glucocorticoids alone. In addition, patients with a serum creatinine level ≥4 mg/dl (hazard ratio, 2.93; 95% confidence interval, 1.77 to 4.85; <0.001) or hypoalbuminemia (hazard ratio, 2.11; 95% confidence interval, 1.32 to 3.34; =0.002) were at higher risk for ESRD. A serum creatinine level ≥4 mg/dl and a percentage of global sclerotic glomeruli ≥60% were the two independent risk factors for ESRD in the sclerotic class.

Conclusions: The histopathologic classification of ANCA-associated GN in combination with serum creatinine and serum albumin levels and treatment regimen is associated with renal outcome in myeloperoxidase-ANCA-associated GN. The evaluation of serum creatinine level and percentage of global sclerotic glomeruli provides additional information on the risk of renal survival in the sclerotic class of myeloperoxidase-ANCA-associated GN.