Citation

Dense fine speckles 70 kDa protein (DFS70)/lens epitheliumderived growth factor (LEDGF) is a nuclear antigen with a characteristic pattern in immunofluorescence assay that was originally identified from the serum of a patient with interstitial cystitis [1]. It was also identified as a growth factor that stimulates cell growth and activates the expression of heat shock and stress-related genes [2], and was shown to interact with HIV-1 integrase and to help target this protein to chromatin [3,4]. Successive studies showed IgG autoantibodies against DFS70 to be associated with various disease conditions [5], including atopic dermatitis (AD) [6], although the actual involvement of these autoantibodies in these diseases has not been confirmed. Recently, we showed that IgE- and IgG4-anti-DFS70 autoantibodies are found in a certain subpopulation of AD patients and that the serum levels of thymus and activation-regulated chemokine (TARC), which reflect the severity of AD [7,8], were significantly higher in the groups that were positive for either autoantibody [9]. IgG-anti-DFS70 is also known to be present in sera from healthy individuals (HI) [10], and it has been proposed that they are a natural autoantibody [11]. In the present study, we established an enzymelinked immunosorbent assay (ELISA) that measures the avidity of anti- DFS70, in order to test the hypothesis that IgG-anti-DFS70 have higher avidity in AD patients than in HI.