Antinuclear antibodies: General introduction

Serum antinuclear antibodies (ANA) are the most used autoimmunity markers in clinical practice at any level. Positivity for ANA, however, is poorly helpful in the diagnostic process of suspect autoimmunity since, for example, serum ANA are also found in 1 in 20 healthy subjects. Patterns observed at immunofluorescence might help in identifying the autoantigens involved that are, in turn, significantly associated to specific forms of autoimmunity. A general overview of ANA patterns and specificity that is proved to be helpful in clinical practice is provided as to diagnostic and prognostic evaluation. As to the latter, it is of note that ANA titers almost universally do not correlate with disease severity.