ANAs and antibodies to DNA: their use in clinical diagnosis.

Antinuclear antibody tests complement clinical data. They acquire meaning in the context of definable rheumatic diseases or in early or otherwise partially expressed systemic rheumatic diseases. Diagnostic tests are not illnesses in themselves; they help define and sub-classify systemic rheumatic diseases when the test information is integrated with the clinical data. In these contexts, ANA tests are powerful adjuncts in clinical diagnosis and disease classification.