Abstract
Objective
Autoantibodies against DFS70 (dense fine speckles 70) antigen (also known as lens epithelium–derived growth factor) have been recently identified among the antinuclear antibodies (ANAs) in patients with atopic disorders. We undertook this study to examine the frequency of anti‐DFS70 antibodies in a large number of healthy people.
Methods
Sera of 597 healthy individuals working in a hospital (142 men, 455 women) were analyzed for ANAs and for anti‐DFS70 antibodies by indirect immunofluorescence (IIF) with HEp‐2 cells as a substrate and by immunoblotting using DFS70 recombinant protein and whole HeLa cell extract.
Results
ANAs were present in 20% of all individuals by IIF. Nine percent of subjects were ANA positive at a serum dilution of 1:40, 4.0% at 1:80, 5.5% at 1:160, 1.0% at 1:320, and 0.3% at 1:640. There were 64 anti‐DFS70 antibody–positive individuals. Surprisingly, this was 11% of the whole population and 54% of the ANA‐positive population. The percentage of female anti‐DFS70 antibody–positive subjects (86%; 55 of 64 subjects) was higher than the percentage of female anti‐DFS70 antibody–negative subjects (75%; 398 of 533 subjects) (P < 0.05). The prevalence of anti‐DFS70 antibody–positive sera decreased with increasing age (P = 0.0017).
Conclusion
Considering that anti‐DFS70 antibody positivity is rare in patients with systemic autoimmune diseases, introducing the anti‐DFS70 antibody examination as a screening test for ANA‐positive persons could be used to rule out systemic autoimmune diseases, resulting in considerable cost‐saving potential. In addition, this test defines a subpopulation of healthy people in whom long‐term followup might reveal health‐related implications of this finding, since anti‐DFS70 antibodies have been shown to be associated with some illnesses.