Anti-DFS70 antibodies are associated with atopic dermatitis and can cause misdiagnosis of connective tissue disease.

Background And Objectives: Antinuclear antibodies (ANA) detected by HEp2 cell immunofluorescence staining are a characteristic finding in patients with connective tissue disease (CTD). However, even detection of highly elevated ANA is not conclusive for CTD and can result in misdiagnosis. Anti-DFS70 antibodies are ANA, which may also be highly elevated in people without CTD. Thus, we wanted to evaluate whether they could cause misdiagnosis of CTD. Since anti-DSF70 antibodies have been associated with atopic dermatitis (AD) in Japan, we wanted to investigate this association and its potential diagnostic relevance in Germany.

Patients And Methods: We retrospectively analyzed data of 40 patients referred for first consultation on CTD and prospectively analyzed the prevalence of anti-DFS70 antibodies in 110 AD patients and 89 controls.

Results: We could not confirm CTD in 75% of our referred patients, 26% of whom had already received systemic treatments. DFS70-typical fluorescence staining was detected in 35% and definitive anti-DFS70 antibodies in 12.5% of these patients. DFS70-typical fluorescence staining was detected in 22% of AD patients and anti-DFS70 antibodies in 10% (versus 5.6% and 0% in control patients, P < 0.001).

Conclusions: Anti-DFS70 antibodies are significantly associated with AD and could be responsible for misdiagnosis of CTD.