What condition is Antinuclear Antigen (ANA) most commonly associated with?

Antinuclear Antigen (ANA) testing is a key laboratory tool in the diagnosis of autoimmune disorders, with the highest association found in Systemic Lupus Erythematosus (SLE). The presence of ANA indicates that the immune system is producing antibodies that target nuclear components of cells, a hallmark of autoimmune pathology.

In SLE, around 95% of patients test positive for ANA, reflecting a strong correlation between the condition and the presence of these antibodies. Other autoimmune conditions can also yield positive ANA results, but the magnitude and frequency of positivity in SLE overshadow those seen in conditions like rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis, where ANA may be present but is not as definitive or prevalent. This specificity makes ANA testing particularly useful in the context of SLE, thereby establishing it as the condition most commonly associated with ANA.