Clinical and pathological features of idiopathic membranous nephropathy patients combined with hyperuricemia

Objective To investigate the clinical and pathological features of idiopathic membranous nephropathy(IMN) patients combined with hyperuricemia. Methods A retrospective analysis was conducted by collecting 125 cases of IMN diagnosed by renal biopsy in our hospital between January 2014 and January 2017. According to the serum uric acid level, the enrolled patients were further divided into two groups:normal serum uric acid group (n=77) and hyperuricemia group (n=48), and the clinical data and pathological features of the two groups were compared subsequently. Results In the 125 patients with IMN, the serum creatinine and blood urea nitrogen levels were significantly higher and the estimated glomerular filtration rate was significantly lower in the hyperuricemia group than those in the normal serum uric acid group (P<0.05 for all). Furthermore, there were no significant differences in 24-h urinary protein quantity, total protein, albumin, cholesterol, triglyceride, low-density lipoprotein, as well as thyroid function indexes of T3, T4 and TSH between the hyperuricemia group and normal serum uric acid group (P>0.05 for all). Renal tissue examination results under light microscope suggested that glomerulus sclerosis, segmental glomerulosclerosis, tubular atrophy/interstitial fibrosis ratio were significantly increased in the hyperuricemia group than those in the normal serum uric acid group (P<0.05 for all). Meanwhile, pathological changes were stage I and stage Ⅱ mainly in the two groups and mesangial hyperplasia was mild predominantly, and there was no statistically significant difference in the arteriole hypertrophy and arteriolar hyaline degeneration between two groups (P>0.05). In the hyperuricemia group, the proportion of dense deposits in the mesangial region was higher than that in the normal serum uric acid group under electron microscopy (P<0.05). Immunopathologic features of patients in both two groups were dominated by immunoglobulin IgG and complement C3 deposition, accompanied by some immunoglobulin IgM deposition and a small amount of complement C1q deposition, with the difference between the two groups being not statistically significant (P>0.05). Conclusions IMN patients with hyperuricemia show marked changes in glomerular and tubulointerstitial diseases, and hyperuricemia may be an important factor in the progression of IMN.