Nodular glomerulosclerosis after renal transplantation without diabetes mellitus

Nodular glomerulosclerosis and renin angiotensin system in Chinese patients with type 2 diabetes

BACKGROUND

Diabetic nephropathy (DN) is a multifactorial and polygenic disease with nodular glomerulosclerosis (NGS) pathognomonic for diabetes and hypertension. Patients with type 2 diabetes and hypertension have characteristic renin-angiotensin system (RAS) gene polymorphisms.

METHODS AND RESULTS

In this retrospective cohort study, we correlated the presence of NGS with renal function, angiotensin-converting enzyme (ACE) genotypes (DD, DI, and II), angiotensinogen (AGT) genotypes (MM, MT, and TT) and immunohistochemical staining characteristics of RAS components in 847 patients and 172 consecutive autopsy cases with type 2 diabetes. T allele of AGT was associated with macroalbuminuria (P = 0.040). Multitude regression analysis revealed ACE insertion (I)/deletion (D) polymorphism as an independent determinant for estimated glomerular filtration rate (eGFR) less than 60 mL min(-1)·1.73 m(-2) (DD carriers: odds ratio [OR] = 3.46, 95% confidence interval [CI] = 1.08-11.07; DI carriers: OR = 3.51, 95% CI = 1.63-7.56). A significant association between NGS and eGFR less than 60 mL min(-1)·1.73 m(-2) also persisted after adjusting for nonlinear relationship (P < 0.001). In NGS patients, immunoreactivity of angiotensin I converting enzyme 2 (ACE2) significantly decreased in glomeruli with mesangial nodules compared with glomeruli without the mesangial nodules.

CONCLUSIONS

These data suggest associations of ACE D allele with glomerular filtration impairment, and NGS with glomerular ACE2 down-regulation and reduced glomerular filtration in Chinese patients with type 2 diabetes.

Idiopathic nodular glomerulosclerosis

Idiopathic nodular glomerulosclerosis is an unusual entity with light microscopic and ultrastructural features similar to those of nodular diabetic glomerulosclerosis but without evidence of abnormal glucose metabolism. We report 2 patients whose renal biopsies showed nodular glomerulosclerosis with afferent and efferent arteriolosclerosis, glomerular basement membrane thickening, focal mesangiolysis and capillary microaneurysm formation, and who had no evidence of abnormal glucose metabolism or other features of diabetes mellitus. Review of the literature shows that, of the 27 reported cases of idiopathic nodular glomerulosclerosis (not including the 2 cases reported herein), 11 showed evidence of abnormal glucose metabolism or were frankly diabetic. Of the remaining 16 cases with normal serum blood glucose measurements, 3 had diabetic retinopathy and 1 had a delayed insulin response curve. The cause and pathogenesis of the glomerular nodules are discussed, and it is suggested that arteriolar stenosis and glomerular ischemia may be involved in the development these lesions.