Background: Pentosidine, an advanced glycation end product, increasingly accumulates in articular cartilage with age, and contributes to the pathogenesis of osteoarthritis (OA). Increased pentosidine concentrations are associated with inflammatory disorders—for example, rheumatoid arthritis. Objective: To compare pentosidine serum concentrations in patients with knee OA and in healthy volunteers and to determine a relationship between pentosidine and cartilage oligomeric matrix protein (COMP)—a marker of articular cartilage destruction. Methods: Paired serum and synovial fluid samples were obtained by arthrocentesis from 38 patients with knee OA and from 38 healthy volunteers. Pentosidine concentration was measured by reverse phase high performance liquid chromatography with fluorescent detection and COMP was determined by sandwich ELISA. Results: Significantly increased serum pentosidine (p<0.01) and COMP (p<0.05) levels were detected in the patients with OA compared with the control group. Serum pentosidine correlated significantly with synovial fluid pentosidine (p<0.001). Pentosidine in synovial fluid (p<0.05) and in serum (p<0.05) correlated significantly with synovial fluid COMP. Pentosidine and COMP concentrations did not correlate significantly with the radiological stage of the disease. Conclusion: Increased pentosidine serum concentration in patients with OA and its correlation with the cartilage destruction marker COMP in synovial fluid suggests that pentosidine may be important in OA pathology and is a new potential OA marker.

Aims: The aim of our study was to determine serum levels of advanced glycation end-products (AGE) in patients with chronic alcohol misuse and to examine their relationship to markers of nutrition and inflammation. Methods: The study group consisted of 23 heavy alcohol drinkers treated for chronic alcohol misuse and 22 healthy controls. Studied parameters included AGE (fluorescence, CML – carboxymethyllysine and pentosidine), lipids, glucose, albumin, leptin, prealbumin, C-reactive protein (CRP) and pregnancy-associated plasma protein A (PAPP-A). Results: AGE fluorescence was significantly higher in chronic alcoholic patients than in healthy subjects (4.3 ± 0.7 × 10³ vs 3.7 ± 0.5 × 10³ AU/g protein, P < 0.005), while CML was only slightly but not significantly elevated (569.1 ± 106.6 vs 545.5 ± 85.8 μg/l) and pentosidine levels did not differ (105.4 ± 29 vs 102.2 ± 23 nmol/l). In alcoholics, AGE correlate significantly negatively with leptin (r = −0.46, P < 0.05) and pentosidine with prealbumin (r = −0.43, P < 0.05), otherwise there was no relationship between AGE and other biochemical parameters (glucose, cholesterol, albumin, CRP, PAPP-A). Conclusion: Our findings suggest a more complex relationship among advanced glycation, oxidative stress and metabolism of ethanol and their link to nutrition and nutrition-associated parameters. AGE as a result of oxidative stress might be similarly linked to increased cardiovascular risk of heavy alcohol drinkers, as are malnutrition and inflammation; however, further studies are needed to confirm this hypothesis.

Background. Uraemia and haemodialysis treatment are associated with microinflammation and oxidative as well as carbonyl stress, which result in enhanced formation of glycoxidation products. Although both glycoxidation and inflammation can contribute to severe vascular and cardiovascular complications, the role that these pathogenic mechanisms play in the complex response of the whole organism remains to be elucidated. Methods. We performed a cross-sectional study in 34 clinically stable chronic haemodialysis patients and in 14 healthy controls while determining serum concentrations of pentosidine, fluorescent advanced glycation end-products (AGEs), advanced oxidation protein products (AOPPs) and acute phase reactants. We further assessed the relationship between these glycoxidation products and parameters of inflammation. Results. Glycoxidation products as well as certain acute phase reactants were elevated in haemodialysis patients. There were significant correlations between AOPPs and inflammatory parameters such as orosomucoid (0.39, P < 0.05), fibrinogen (0.49, P < 0.05) and pregnancy-associated protein A (PAPP-A; 0.46, P < 0.05), but no correlations between pentosidine or fluorescent AGEs and any of the inflammatory parameters. Conclusion. Oxidative damage showed a closer relationship to inflammation than advanced glycation (glycoxidation). AOPPs may represent a superior acute biochemical marker, whereas AGEs may better describe chronic long-lasting damage.