[Antinuclear and antinucleoprotein antibodies Laboratory and clinical aspects].

Autoimmune diseases result from a breakdown of immune tolerance, which can precede clinical manifestations by several years. Screening for antinuclear antibodies (ANA) is commonly performed in patients with nonspecific symptoms suggestive of a systemic autoimmune disease. In the absence of a compatible clinical context, detecting autoantibodies can cause confusion and concern. This article provides an integrated clinicobiological analysis of ANA and extractable nuclear antigen testing, emphasizing the importance of rigorous assay validation and contextualized interpretation to prevent overdiagnosis and unnecessary investigations.