Pre-treatment antinuclear antibody positivity, therapeutic efficacy and persistence of biologics in rheumatoid arthritis

Introduction: Rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) are poor prognostic factors in rheumatoid arthritis (RA). The therapeutic implication of antinuclear antibody (ANA) positivity in RA is still debated. The study aims to evaluate ANA positivity as a prognostic factor for the therapeutic response to biologics in RA.

Methods: observational study; data were gathered from the Romanian Registry of Rheumatic Diseases which comprises all biological-treated RA patients in Romania. We included only RA patients who were tested for ANA before initiating biologics.

Results: A number of 740 RA patients were included (72.4% treated with TNF-α blockers, 27.6% with rituximab). Compared to ANA-negative patients, ANA-positive patients (26.9%) had: a higher disease activity score (DAS28) prior to biologics, at the time of treatment switch and after the observation period; lower drug persistence (p < 0.001 for all tests). Multiple linear regressions showed that ANA positivity is a significant predictor of the current value of DAS28, independently of the presence of RF and/or ACPA (p < 0.05).

Conclusion: ANA positivity in RA patients before starting biologics may be a poor prognosis factor for efficacy and drug persistence. Further studies are needed to confirm these observations.