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.