Changes in Clinicopathological Characteristics of Patients with Idiopathic Membranous Nephropathy: A Single-Center Retrospective Study

Background: The prevalence of Idiopathic Membranous Nephropathy (IMN) among patients with Primary Glomerular Disease (PGD) has increased in China. Objectives: This cross-sectional studyaimedto investigate changes in the clinicopathological features associated withIMNin northeast China. Methods:We analyzed clinical and pathological data of 1,198 patients with IMN among 4,083 patients hospitalized with PGD undergoing renal biopsy from January 1, 2005, to December 31, 2018 at the Second Hospital of Jilin University in northeast China. Enrollees were divided into two groups: those seen from 2005 to 2011 (Group 1) and those seen from 2012 to 2018 (Group 2). We compared the clinicopathological features between Group 1 and Group 2. Results: The percentage of patients with IMN among those with PGD increased over the 14 years of the study (P = 0.001). The maleto- female ratio, prevalence of microscopic hematuria, and proteinuria levels were higher in Group 2 than in Group 1 (P < 0.05). Among those with PGD, the percentages of patients with IMN-total, IMN-I, IMN-II, and IMN-III+IV, as well as Tubulointerstitial Lesion (TIL) scores, were higher in Group 2 than in Group 1 (P < 0.05). Finally, age (P < 0.001), degree of proteinuria (P < 0.001), and serum triglyceride level (P = 0.027) were significantly associated with TIL scores among patients with IMN. Conclusions: Membranous nephropathy is now the leading cause of PGD, with increased TIL scores during the study period. Advanced age, high proteinuria, and serum triglyceride levels represent the independent risk factors for severe TIL among patients with IMN.