Background and aims Anti-dense fine speckled 70 (anti-DFS70) antibodies were initially identified as an ANA IIF pattern from patients with interstitial cystitis; however, some recent studies showed that anti-DFS70 antibodies are common among ANA positive individuals with no evidence of systemic autoimmune disease (SAD)(Mahler M. 2012). Information of anti-DFS70 in Latin-American countries is very limited. We determined the prevalence of Anti-DFS70 antibodies in a Colombian cohort.

Methods We evaluated individuals≥18 years old, including 100 SLE patients, 102 SADs, 200 healthy controls, and 56 subjects suspected of having autoimmune disease with ANA positive and negative anti ds-DNA antibodies. The presence of anti-DFS70 antibodies was determined by QUANTA Flash by chemiluminescent techniques (Inova/Werfen, San Diego)

Results Our final cohort included 458 samples. The mean age of SLE patients was 33±12 years, for SADs was 41±19 and for healthy controls was 36±10 years. The main diagnoses of SAD were: Vasculitis (n=28), RA (n=21), Systemic sclerosis (n=12), primary antiphospholipid syndrome (n=11), dermatomyositis (n=10) among others. Racial/ethnic breakdown was: 76% Mestizo and 20% Afro-latin Americans. Anti-DFS70 antibodies were positive in 1.8% of subjects with ANAs positive/anti DNA negative, in 1% of SLE patients, 0.9% of patients with other SADs and in 0.5% of healthy controls. Given the low prevalence of anti-DFS70 antibodies, no clinical correlations were possible.

Conclusions Despite anti-DFS70 antibodies are a good diagnostic tool for discrimination among healthy individuals and SADs (including SLE), we found a very low prevalence of anti-DFS70 antibodies in our Colombian cohort.