The recognition of anti-nuclear antibody's dense fine speckled pattern and the detection of anti-DFS70 antibodies in the laboratory practice: Its prevalence and clinical significance

Anti-nuclear antibody test (ANA) is the test commonly requested for the working diagnosis of systemic autoimmune rheumatic diseases (SARDs) particularly in ANA-associated rheumatic diseases (AARDs) such as SLE, systemic sclerosis, Sjogren syndrome, mixed connective tissue diseases, and dermatomyositis. Dense fine speckled (DFS) pattern is an ANA fluorescence pattern that is commonly encountered in laboratories. This pattern is largely detected among the healthy population and in non-SARDs patients. Although this pattern is still can be observed among SARDs patients, the low prevalence of monospecific or isolated anti-DFS70 antibodies makes it useful for ruling out AARDs diagnosis. Thus, the inclusion of anti-DFS70 antibodies is perhaps logical for the exclusion of SARDs/AARDs. This review provides evidence of the prevalence of anti-DFS70 antibodies in different populations including healthy individuals, patients with SARDs and non- SARDs. The algorithm that includes the detection of anti-DFS70 antibodies during ANA screening is also suggested.