Atypical aspects of antinuclear antibodies

Antinuclear antibodies (ANA) constitute a heterogeneous group of autoantibodies directed against a wide variety of antigens of nuclear or cytoplasmic origin. The search for ANA is a frequent reason in clinical biology. The interest in ANA lies in the diagnostic value of some of them for the diagnosis of connective tissue disease and certain organ-specific or non-specific autoimmune diseases. According to the 1st international consensus for standardizing the nomenclature of AAN ＂International consensus on anti nuclear antibodies staining Patterns＂ (2014), it is recommended to associate cytoplasmic fluorescence and that of the mitotic apparatus with nuclear fluorescence in the rendering of results research of AANs. However, in current practice, the reporting of ANA results lacks standardization between laboratories. We analyzed the different aspects (nuclear, cytoplasmic and mitotic) of ANA performed in our laboratory in accordance with the ICAP classification and we studied the clinical significance of the cytoplasmic aspects associated or not with nuclear marking.