Interpretation of a positive antinuclear antibody (ANA) result in people with mild nonspecific symptoms

Note: Only 10% of people with mild, nonspecific symptoms, and intermediate or high antinuclear antibody (ANA) titre, will go on to develop a definable inflammatory connective tissue disease, which usually occurs within 24 months.

Some people who present with mild nonspecific symptoms (eg arthralgia, fatigue) may have a positive antinuclear antibody (ANA) result in intermediate or higher titre (eg 1:640 or more). Only 10% of these people will go on to develop a definable inflammatory connective tissue disease and this usually occurs within 24 months. The remaining 90% of these people may continue to have mild nonspecific symptoms that do not fit a particular diagnosis. Avoid inappropriate diagnostic labels for all people, to limit their anxiety and inaccurate prognosis.

For people with mild nonspecific symptoms, management is directed at controlling the common clinical symptoms—see Management for the common clinical features of inflammatory connective tissue diseases for details.

Clinically reassess all people with mild nonspecific symptoms after 12 months. Only order repeat ANA testing and specific autoantibody tests (see Common tests and prevalence of specific autoantibodies associated with inflammatory connective tissue diseases) if the patient develops new symptoms or signs that are more suggestive of a defined inflammatory connective tissue disease. Refer people with symptoms and signs highly suggestive of inflammatory connective tissue disease urgently to a specialist.

Note: Only order repeat antinuclear antibody (ANA) and specific autoantibody tests if the patient develops new symptoms or signs that are highly suggestive of inflammatory connective tissue disease.

If there is no change in the patient’s clinical presentation after 12 months, determine the need for ongoing review or monitoring based on individual patient factors.