Clinicopathological features of idiopathic membranous nephropathy in patients of different ages

Idiopathic membranous nephropathy (IMN) is increasingly seen in elderly patients, however, the clinicopathological features of IMN are still elusive. This study aimed to compare and analyze the clinicopathological features among IMN patients of different ages. In this study, a total of 142 IMN patients were recruited and grouped by age. After comparing and analyzing their clinical and pathological data, we found that (1) The course of disease in the elderly group was longer, but not significantly (P=0.834). The glomerular filtration rate (eGFR), triglyceride and hemoglobin levels of the elderly group were significantly lower than those of the young and middle-aged groups (P=0.001, P=0.021, P=0.031), and the incidence of nephrotic syndrome was significantly higher than the other two groups (P=0.026). (2) By immunofluorescence, deposition in the glomerulus was shown with IgG4 (88.03%) and C3 (97.89%) predominance. The mild glomerular sclerosis (82.05%), tubule atrophy (92.31%) and renal arterial wall thickening (25.64%) in the elderly group were much higher than those in the young (44.74%, 63.16%, 2.63%) and middle-aged groups (60%, 83.08%, 18.46%), which is statistically significant (P=0.001, P=0.004, P=0.016). (3) The serum PLA2R antibodies in IMN patients was negatively correlated with the level of albumin (P=0.001), whereas there was no significant correlation between PLA2R and 24 h urine protein (P=0.180). In conclusion, elderly IMN patients are more likely to be accompanied by nephrotic syndrome with more serious pathological kidney damage. PLA2R level is negatively correlated with serum albumin, but has no correlation with 24 h urine protein.