The significance of dense fine speckled pattern in antinuclear antibody-associated rheumatic disease and coexisting autoantibodies: A propensity score-matched cohort study

Aim: To investigate the relationship between the prevalence of antinuclear antibody (ANA) -associated rheumatic diseases (AARD) and the presence of dense fine speckled (DFS) and homogeneous patterns in ANA tests.

Methods: This retrospective study enrolled adult patients with either a DFS or homogeneous pattern in their ANA test. A mixed pattern was defined as the presence of more than one pattern reported in the test. The presence of anti-DFS70 antibodies and other common autoantibodies were detected using EUROLINE ANA Profile 23. A 1:2 propensity score matching was applied to control for demographic and other interfering factors.

Results: A total of 59 patients with a DFS pattern were enrolled and compared with a matched homogeneous group. The DFS group had a significantly lower prevalence of AARD (3.4% vs. 16.9%, p = .008) and the subgroup with anti-DFS70 antibodies showed an even lower prevalence (2% vs. 20%, p = .002). Among the 33 patients with monospecific anti-DFS70 antibodies, five had a mixed pattern, and all patients with common autoantibodies had an isolated DFS pattern.

Conclusions: The findings of this study suggest that patients with a DFS pattern in their ANA test may have a lower prevalence of AARD compared with those with a homogeneous pattern. However, an isolated DFS pattern in ANA testing does not necessarily indicate the presence of monospecific anti-DFS70 antibodies or AARD. Confirmatory testing for the monospecific anti-DFS70 antibody is mandatory to exclude AARD.