AB0650 POSITIVE ACPA IS ASSOCIATED WITH GREATER GRIP FORCE AND LOWER DISEASE ACTIVITY IN PATIENTS WITH EARLY RHEUMATOID ARTHRITIS
Authors: C. Turesson, M. Rydholm, M. Hameed, G. Cagnotto, A. Eberhard
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Impaired hand function is a consequence of rheumatoid arthritis (RA), resulting in reduced grip force. It has been established that active arthritis (in particular in the wrist and the first metacarpophalangeal joint), pain and elevated erythrocyte sedimentation rate are associated with lower grip force. Whether grip force is different in seropositive compared to seronegative patients with early RA has not been extensively studied. <h3>Objectives:</h3> To investigate the relation between autoantibody status, disease activity and grip force in patients with early RA. <h3>Methods:</h3> In a retrospective study, consecutive patients diagnosed with RA and a reported symptom duration of &lt; 12 months at a single rheumatology center in 2012-2016 were included. All patients fulfilled the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism and/or the 1987 ACR classification criteria for RA. Patients were assessed and followed according to current clinical practice, including structured examination by occupational therapists for most patients. Clinical data from the time of diagnosis were retrieved from structured reviews of the medical records. Average grip force values of the right hand were evaluated and expressed as % of expected values, based on age- and sex-specific reference values (1). The relations between baseline disease parameters (rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) status, and disease activity measures) and the first available grip force value were assessed using linear regression models. <h3>Results:</h3> In a total of 367 included patients with early RA, grip force had been measured in 289 cases (75.1 % females, mean age at diagnosis 58.4 years, mean symptom duration 5.7 months (standard deviation, SD, 3.2), mean DAS28 5.1 (SD 1.5)). RF and ACPA were positive in 68.1 % and 66.8 %, respectively. The median time from diagnosis to first grip force was 1.7 months (interquartile range 0.8-2.9). The mean grip force was 50.1 % of expected. In linear regression analyses, higher values for DAS28, individual components of DAS28, patient reported pain and CRP were associated with lower grip force (Table 1). ACPA positive patients had significantly higher grip force compared to those with negative ACPA (β10.6 (95 % confidence interval (CI) 1.9 to 19.4), whereas there was no difference by RF (Table 1). Patients with positive ACPA had lower swollen joint counts (0-28) at diagnosis (mean 5.9 vs 7.4, p=0.02), and a trend towards lower CRP (median 7.0 vs 9.9 mg/l, p=0.10). In multivariate analysis, adjusted for swollen joint count and CRP (quartile), there was a trend towards an association between positive ACPA and greater grip force, although it did not reach statistical significance (β8.1; 95 % CI -0.1 to 17.0). <h3>Conclusion:</h3> Higher disease activity parameters at diagnosis were associated with lower grip force in patients with early RA. ACPA positive patients had greater grip force, partly due to lower numbers of swollen joints and lower CRP at diagnosis in this subset. This suggests that with modern algorithms for diagnosing RA, more extensive synovitis and greater impact on hand function is seen in early ACPA negative RA compared to ACPA positive disease. <h3>REFERENCES:</h3> [1] Nilsen et al. Scand J Occup Ther. 2012;19:288-96. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> Carl Turesson AbbVie, Boehringer-Ingelheim, Nordic Drugs, Novartis, Pfizer, Roche., Maria Rydholm: None declared, Mohaned Hameed Novartis, Giovanni Cagnotto: None declared, Anna Eberhard: None declared.