Prevalence of anti-DFS70 autoantibodies in a Latin American cohort of patients with systemic lupus erythematosus and without autoimmune diseases.

INTRODUCTION/OBJECTIVES: Anti-dense fine speckled 70 (DFS70) autoantibodies were reported to be more prevalent in healthy individuals than those with autoimmune diseases such as systemic lupus erythematosus (SLE). We determined anti-DFS70 autoantibody prevalence in a Latin American cohort of patients with SLE and healthy individuals.

METHODS

This study included 127 individuals with anti-nuclear antibodies (ANAs; > 1:160) suggesting the presence of anti-DFS70, including 64 patients with SLE and 63 healthy controls. The anti-DFS70 autoantibodies were determined by immunoadsorption using NOVA Lite HEp-2 Select kit with DAPI. Negative fluorescence after adsorption with the DFS70 antigen indicated anti-DFS70 autoantibody positivity.

RESULTS

The presence of anti-DFS70 autoantibodies was confirmed by indirect immunofluorescence in 21 (33.3%) healthy controls and 8 (12.5%) patients with SLE (p = 0.005). Among the anti-DFS70-positive patients with SLE, the most frequent compromise was renal involvement in six cases (75%), 4 patients (37.5%) were positive for anti-Sm, which was the most frequently associated antibody, and one patient (12.5%) was positive for anti-DNA.

CONCLUSIONS

Anti-DFS70 autoantibodies might be considered a biomarker to differentiate patients with SLE from ANA-positive individuals without autoimmune diseases.

KEY POINTS

• In a Latin American cohort, the anti-DFS70 was higher in individuals without autoimmune diseases compared with that in patients with SLE.• The anti-DFS70 might have utility as a biomarker of exclusion in patients with non-specific clinical signs of AARDs.