Crossline levels in serum and erythrocyte membrane proteins from patients with diabetic nephropathy

Crossline is one of the structurally defined adducts of advanced glycation endproducts (AGEs) which has both a crosslink and fluorescence similar to A GE-protein in vivo. Crossline was measured in serum and erythrocyte membran e proteins (EMP) fi om 52 type 2 diabetic patients using a specific enzyme- linked immunosorbent assay system. Serum and EMP crossline levels in the di abetic patients were significantly higher than those in normal control. The patients with advanced diabetic nephropathy (serum creatinine levels of mo re than 1.2 mg/dl) had markedly elevated serum crossline levels compared to those with moderate diabetic nephropathy (clinical proteinuria) (180 +/- 5 1.7 vs. 71.8 +/- 18.4 pmol/ml; P < 0.01). On the other hand, there were no significant differences in EMP crossline levels between the two. EMP crossl ine levels in the patients with moderate diabetic nephropathy (8.8 +/- 2.9 pmol/mg protein) and those with advanced diabetic nephropathy (9.7 +/- 3.0 pmol/mg protein) were significantly higher than those without clinical prot einuria (6.4 +/- 1.9 pmol/mg protein; P < 0.01). The present study demonstr ated that EMP crossline levels were associated with the presence of nephrop athy in patients with type 2 diabetes mellitus. Serum crossline levels were significantly influenced by remaining renal function. The measurement of c rossline from a blood sample could provide us with important information fo r the study of clinical evaluation and pathogenesis of diabetic complicatio ns. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.