Plasma sRAGE and N-(carboxymethyl) lysine in patients with CHF and/or COPD

Background Knowledge of the role of the receptor for advanced glycation end products (RAGE), particularly its soluble form (sRAGE), and of its advanced glycation end product (AGE) ligand, N-(carboxymethyl)lysine adducts (CML), is limited in chronic heart failure (CHF) and in chronic obstructive pulmonary disease (COPD). We evaluated whether the AGE/RAGE system is activated in stable CHF and COPD, and whether plasma sRAGE and CML levels are affected by clinical and functional parameters. Materials and methods We measured plasma levels of sRAGE and CML using a sandwich enzyme-linked immunosorbent assay (ELISA) in 143 subjects, aged65years, divided into five groups: 58 with CHF, 23 with COPD, 27 with CHF+COPD and 35 controls (17 healthy smokers and 18 healthy nonsmokers). Individuals with diabetes were excluded from the study. Results Plasma levels of sRAGE and CML were higher in CHF patients than in controls [sRAGE: 0 center dot 48 (0 center dot 370 center dot 83) vs. 0 center dot 42 (0 center dot 290 center dot 52)ng/mL, P=0 center dot 01; CML: 1 center dot 95 (1 center dot 582 center dot 38) vs. 1 center dot 68 (1 center dot 432 center dot 00) ng/mL, P=0 center dot 01]. By contrast, sRAGE and CML were not different between both COPD and CHF+COPD patients and controls (0 center dot 05). N-terminal pro-brain natriuretic peptide (Nt-pro BNP) correlated with sRAGE, but not with CML, in the patient groups: CHF (r=0 center dot 43, P<0 center dot 001), COPD (r=0 center dot 77, P<0 center dot 0001) and CHF/COPD (r=0 center dot 43, P=0 center dot 003). Conclusions Plasma levels of sRAGE and CML are increased in CHF, but not in COPD patients. The robust association between NT-pro BNP, a diagnostic and prognostic marker in CHF, and sRAGE concentrations might suggest a possible BNP pathway of amplification of inflammation via the AGE/RAGE system.