Prevalence and clinical associations of antinuclear antibodies (ANA) in spondyloarthropathies

Spondyloarthropathies (SpA) are a broad and diverse group of diseases with highly variable clinical manifestations. Due to this wide range of symptoms and their frequent overlap with other disease entities, SpA present numerous diagnostic and therapeutic challenges. Moreover, the pathogenesis of SpA remains unexplained. While the currently prevailing hypothesis suggests an autoinflammatory mechanism, the involvement of autoimmune processes has not been ruled out. To explore this possibility, the present study aimed to assess the presence of antinuclear antibodies (ANA) and their clinical associations in patients with SpA.

The analysis included 117 consecutive patients with different forms of SpA, i.e., ankylosing spondylitis (n ​= ​52), psoriatic arthritis (n ​= ​34), and non-radiographic SpA (n ​= ​31). They underwent clinical evaluation, and serum samples were collected from each for ANA testing using indirect immunofluorescence.

ANA were found in 46 ​% of patients with SpA. No statistically significant association was found between ANA and diagnosis of specific SpA or clinical symptoms. Interestingly, the highest prevalence of ANA (63 ​%) was found in women with non-radiographic spondyloarthropathy and the lowest (38 ​%) in males with ankylosing spondylitis, however, the difference did not reach statistical significance.

The results of our study suggest that ANA are frequent in patients with SpA, in particular in women with early, non-radiographic SpA which may be of clinical significance. However, further studies, involving larger populations, are necessary to clarify the significance of ANA presence in SpA patients.