Serum advanced glycation end-products and αB-crystallin in diabetic retinopathy patients.

αB-crystallin, one of the small heat shock proteins, which is also known as HSPB5, has cytoprotective effects under inflammatory conditions. Advanced glycation end-products (AGE) are produced through non-enzymatic glycation under conditions of hyperglycemia and they contribute to angiogenesis and inflammation. The aim of this study was to examine the levels of serum αB-crystallin and AGE concentrations in blood samples collected from proliferative diabetic retinopathy (PDR) patients. Blood samples were collected from seven diabetic patients with PDR and eight patients without diabetes mellitus who underwent vitrectomy due to PDR and idiopathic macular diseases, respectively, in a single center. The levels of serum αB-crystallin and AGE were measured by ELISA and correlations were assessed statistically. The serum levels (mean ± SEM) of AGE were significantly higher in PDR patients (28.41±0.46 µg/ml) than in patients with non-diabetic macular diseases (25.76±0.60 µg/ml; P=0.015), whereas there was no significant difference in serum αB-crystallin levels. There was one patient with an extremely high level of αB-crystallin, who was treated with systemic corticosteroid due to chronic autoimmune inflammatory diseases. The current prospective study showed that serum AGE levels were significantly higher in PDR patients; however, no correlations between serum AGE and αB-crystallin levels were identified.