High-avidity IgG Autoantibodies against DFS70/LEDGF in Atopic Dermatitis

Abstract

Objective: Dense fine speckles 70 kDa protein (DFS70)/lens epithelium-derived growth factor (LEDGF) autoantibodies have been reported to be present in serum samples from patients with atopic dermatitis (AD) as well as from healthy individuals (HI). We previously revealed that IgE- and IgG4-anti-DFS70 autoantibodies were found in patients with AD and that their presence was associated with high levels of thymus-and activation-regulated chemokine. Our aim was to determine the avidity of IgG-anti-DFS70 antibodies in patients with AD relative to that avidity in HI.Patients and methods: This study was undertaken to measure the avidity of IgG-anti-DFS70 autoantibodies in AD and HI groups, in comparison with the major recall antigen diphtheria toxoid (DT) and to evaluate the relevance of IgG-anti-DFS70 autoantibodies to the disease. We measured the avidity of IgG-anti-DFS70 autoantibodies and anti-DT antibodies in sera that were positive for IgG-anti-DFS70 autoantibodies, obtained from 20 AD patients and 20 HI using enzyme-linked immunosorbent assay.Results: The avidity of anti-DFS70 autoantibodies was significantly higher (p<0.01) in the AD patients than in the HI, whereas there was no difference in the avidity of anti-DT between the two groups. There was also no positive correlation between the avidity and the titer of anti-DFS70 in the both groups. In contrast, positive correlation was shown between the serum levels and the avidities of anti-DT.Conclusion: Our findings indicate that AD patients might have significantly high-avidity IgG-anti-DFS70 autoantibodies and that this avidity might be a novel serological marker for a certain AD subpopulation.