What question did this study set out to answer?

This research aims to evaluate the prevalence and clinical significance of anti-DFS70 antibodies among patients with undefined diseases and systemic autoimmune rheumatic diseases (SARD).

July 3, 2026Open Access

Clinical significance of anti-dense fine speckled 70 antibodies in dense fine speckled immunofluorescence positive patients, systemic autoimmune rheumatic diseases, and controls

Key Points

This research aims to evaluate the prevalence and clinical significance of anti-DFS70 antibodies among patients with undefined diseases and systemic autoimmune rheumatic diseases (SARD).
Evaluated sera from patients with undefined disease and controls for dense fine speckled (DFS) pattern via indirect immunofluorescence (IIF).
Confirmed positive samples using anti-DFS70 ELISA and line immunoassay (LIA); compared results between undefined disease, SARD, and controls.
Assessed positive rates and clinical correlations with disease activity in SARD patients.
DFS IIF pattern observed in 0.25% of undefined disease referrals, 0.57% of SARD patients, and 0.4% of controls.
90% anti-DFS70 positivity in undefined disease sera compared to 15.4% in SARD and 100% in controls; significant association with SLE (P=0.003).
Higher anti-DFS70 levels correlate with elevated SLEDAI scores and renal involvement in SARD (P<0.001).

Abstract

Background and objectives The dense fine speckled (DFS) anti-nuclear antibody (ANA) pattern, caused by anti-DFS70 antibodies, is often misunderstood due to its low association with systemic autoimmune rheumatic diseases (SARD) and presence in healthy individuals. Few studies suggest monospecific anti-DFS70 antibodies may exclude SARD. Given limited data from India, we aimed to assess the prevalence and clinical associations of anti-DFS70 antibodies in undefined disease, SARD, and controls. Methods Sera from patients with undefined disease and non-rheumatic disease controls were screened for DFS pattern during the evaluation for ANA by indirect immunofluorescence (IIF); positive samples were confirmed using anti-DFS70 ELISA and line immunoassay (LIA). SARD sera were tested by ANA IIF, ELISA, and LIA. Results DFS IIF pattern was observed in 0.25%, 0.57% and 0.4% of undefined disease referrals, SARD patients, and controls respectively. ELISA anti-DFS70 and LIA were positive in 90% of undefined disease sera, 15.4% vs . 5.7% of SARD cases, and 100% of controls, respectively. ELISA and LIA showed almost perfect agreement in undefined disease (κ= 0.861). In SARD group, anti-DFS70 ELISA positivity was predominantly observed in SLE ( P =0.003); higher ELISA optical density, higher systemic lupus erythematosus disease activity index (SLEDAI) scores ( P <0.001), anti-dsDNA ( P =0.0001), and renal involvement ( P =0.014) being significant observations. Monospecific anti-DFS70 antibodies by LIA were significantly common in undefined disease ( P <0.001). Interpretation and conclusions DFS pattern with monospecific anti-DFS70 antibodies suggests lower likelihood of SARD. Anti-DFS70 antibodies are uncommon in SARD and coexist with other disease-specific autoantibodies. These findings highlight the complexity of interpreting anti-DFS70 antibodies and underscore the need for comprehensive serological testing and clinical correlation.

Ask AI

Helpful

Bookmark

View Full Paper