Detection of free elastin-derived peptides among diabetic children

Elastin breakdown products are found in the serum of all human subjects. The presence of these elastin-derived peptides (EDP) and the corresponding antibodies in circulation leads to formation of circulating immune complexes (CIC). The aim of this study was to determine if serum level of free-EDP (unbound in CIC) correlate with the development of microvascular complications in children with Type 1 (insulin-dependent) diabetes mellitus. To this end we used a method for detecting immune complexes (CIF-ELISA) in combination with an ELISA for detection of EDP. The levels of free EDP were studied in sera of 81 diabetic children (mean age 13.46 ± 3.51 years, diabetes duration 5.17 ± 4.21 years). Forty-two of the children had vascular complications (group 1) and 39 were without vascular complications (group 2). Twenty-one healthy children (mean age 12.6 ± 2.47 years) were used as controls. Diabetics showed significantly higher levels of free EDP (68.1 ± 25 ng/ml versus 51 ± 12.5 ng/ml; p = 0.003) compared to the control group. In group 1, free EDP showed significantly higher levels than controls (78.9 ± 25.6 ng/ml versus 51 ± 12.5 ng/ml; p = 0.0001). About 38 of 81 (47%) patients were positive for free EDP (30/42 – 71% in group 1 and 8/39 – 21% in group 2). Free EDP levels in all diabetics showed a correlation with insulin dose (r = 0.23; p = 0.041), and microalbuminuria (r = 0.57; p = 0.0001). Patients who had vascular pathology showed a correlation of free EDP with microalbuminuria (r = 0.41; p = 0.0081), retinopathy (r = 0.32; p = 0.041), insulin dose (r = 0.37; p = 0.02), HbA1c (r = 0.35; p = 0.03), systolic blood pressure (r = 0.30; p = 0.045) and total cholesterol (r = 0.36; p = 0.02). These findings suggest that elevated levels of free EDP are associated with the development of diabetic vascular complications in children.