Affiliations: Centre for Diabetes and Endocrinology, Jawaharlal
Nehru Medical College, Aligarh Muslim University, Aligarh, U.P., India | Department of Medicine, Jawaharlal Nehru Medical
College, Aligarh Muslim University, Aligarh, U.P., India | Department of Biochemistry, Jawaharlal Nehru Medical
College, Aligarh Muslim University, Aligarh, U.P., India
Abstract: Aims: The vascular tissues have a long memory of their previous
glycemic control and intervention studies have demonstrated that microvascular
complications are highly correlated with mean glycemic control as measured by
glycolated hemoglobin A_{1}C (HbA_{1}c). The present study was carried out
to evaluate the autoantibodies against glycosylated DNA (DNA-AGEs) in diabetic
sera to see if the level of HbA1c has correlation with the activity of
DNA-AGEs, another marker of chronic glycemia. Methods: Glucose-6-phosphate induced glycosylation of native DNA was studied in 150
diabetic sera (T1DM=9, T2DM=141) by spectroscopic techniques (UV and
fluorescence) and agarose gel electrophoresis. Direct binding and inhibition
enzyme immunoassays were carried out to evaluate binding and specificity of
anti-glycated-DNA autoantibodies (anti-DNA-AGE autoantibodies) in sera of
diabetes patients. A quantitative estimation of HbA_{1c} was carried out in
normal and diabetes sera. Results: Anti-DNA-AGEs autoantibodies in 55%
of diabetic sera (85/150) showed more binding with glycated-DNA compared to
native DNA which was subjected to inhibition ELISA indicating true interaction
of these autoantibodies in diabetes with glycated DNA. Higher binding with
glycosylated-DNA against native-DNA was observed in subjects with HbA1c of 9.8
± 3.3% compared to those with HbA1c of 7.7 ± 1.7% (p<
0.001). Linear correlation analysis showed that mean absorbance difference was
significantly related to HbA1c (r=0.486, p< 0.001), nephropathy (r=
0.239, p< 0.003), retinopathy (r=0.165, p< 0.05). Conclusions: Autoantibodies against glycosylated DNA were correlated with
HbA_{1}c and microvascular complications and may be useful as another
biomarker for assessment of chronic glycemia.
