Journal of Nephrology & Therapeutics

Meta-Analysis of Association between Pathological Characteristics and Renal Outcomes in Adult Idiopathic Membranous Nephropathy

Abstract

Yizhi Chen, Guangyan Cai and Xiangmei Chen

Background and objectives: The associations of pathological features with renal outcomes in adult Idiopathic Membranous Nephropathy (IMN) are still controversial. A meta-analysis was performed to assess whether pathological features could independently predict risk of progressive kidney disease in adult IMN patients. Methods: The PubMed database (January 2000 to September 2013) was searched to identify cohort studies of adult IMN patients (≥ 50 patients for each study) in which at least one of the following pathological features was assessed: segmental sclerosis, tubular atrophy/interstitial fibrosis, arteriosclerosis, C3 deposits by immunofluorescence, and the stage or heterogeneity of electron dense deposits by electron microscopy. Renal outcomes included development of renal insufficiency or progression to ESRD. Results: Nine cohort studies were included. A total of 2080 patients with 252 hard endpoints (renal insufficiency or ESRD) were reported. Segmental sclerosis was significantly associated with poor renal outcomes (8 studies with 1622 patients: hazard ratio, 1.59 [95% confidence interval, 1.07-2.37], P=0.02). Tubular atrophy/interstitial fibrosis and arteriosclerosis were also significantly associated with poor renal outcomes (7 studies with 1569 patients: 3.85 [2.16-6.87], P<0.000001; and 5 studies with 1349 patients: 1.83 [1.17-2.86], P=0.008). There were insufficient data to systematically assess the independent predictive value of C3 deposits and the stage and heterogeneity of electron dense deposits. Conclusions: Significant associations of renal outcomes with segmental sclerosis, chronic tubule interstitial injury, and arteriosclerosis were only confirmed in two, five, and one of nine included studies, respectively. However, this meta-analysis indicated that each of these pathological features was significantly associated with progression of kidney disease. More methodologically sound and sufficiently powered prospective cohort studies with adequate number of patients and length of follow-up are still urgently needed to address the questions regarding prognostic utility of pathological features in adult IMN patients.