Prognostic value of longitudinal antinuclear antibody dynamics in rheumatoid arthritis: a retrospective cohort study

BackgroundThe prognostic value of longitudinal antinuclear antibody (ANA) dynamics in rheumatoid arthritis (RA) remains unclear.ObjectivesTo examine whether ANA development (titer rise/seroconversion) is associated with 12-month clinical remission and to develop a prediction model for DAS28-CRP remission.MethodsWe retrospectively enrolled 688 adults with RA (2010 criteria) from 2016–2023. ANA was assessed at baseline and 6 months (± 2 months); development was defined as a ≥1-dilution increase or seroconversion (<1:80 to ≥1:80).

The primary endpoint was DAS28-CRP remission at 12 months (<2.6); other endpoints were secondary/exploratory. We used propensity score matching where appropriate.

Multivariable logistic regression identified predictors, with performance assessed by AUC and calibration. Subgroup analyses distinguished seroconversion from titer elevation, and were stratified by baseline RF/anti-CCP status.

Sensitivity analyses used a higher positivity threshold (≥1:160).ResultsBaseline ANA positivity was 63.7%, typically low titers (1:80, 1:160). Among 467 patients with serial ANA data, 94 (20.1%) exhibited ANA development, which was associated with significantly higher post-treatment disease activity and lower remission rates across multiple criteria (e.g., DAS28-CRP 43.8% vs 65.2%, p=0.004).