INTRODUCTION: Rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (ACPA) are used in the diagnosis and prognostication of rheumatoid arthritis (RA). We wanted to determine the specific contributions of RF and ACPA to the biological nature of RA and whether they act synergistically. METHODS: We identified 731 patients from our prospective multi-ethnic RA cohort and categorised them into four groups: ACPA-positive, RF-positive, doubly positive and doubly negative. We compared the demographics, Disease Activity Score-28, Health Assessment Questionnaire score, quality of life using Short Form 36 and the use of prednisolone and disease-modifying antirheumatic drugs (DMARDs) of these patient groups. RESULTS: Four hundred and ninety-one patients (67.2%) were ACPA+RF+, 54 (7.4%) were ACPA+RF-, 82 (11.2%) were ACPA-RF+ and 104 (14.2%) were ACPA-RF-. Mean disease duration before the study entry was not different in the four groups. Patients with older age of onset were less likely to be positive for RF and ACPA. Fewer ACPA+RF+ patients were in remission compared to those in the other groups ( P < 0.05). Erythrocyte sedimentation rate (ESR) was higher at study entry in the ACPA+RF+ group (40.4 mm/h vs. 30.6-30.9 mm/h, P < 0.05). Prednisolone and number of DMARDs used were higher in the ACPA+RF+ group compared to the doubly negative group. There were no differences in the functional status and quality of life. CONCLUSIONS RA patients who were positive for both ACPA and RF had lower remission rate, higher baseline ESR and required more corticosteroid and DMARD treatment compared to those who were singly positive or doubly negative. Being doubly positive confers a worse outcome to RA patients.
Humans ; Arthritis, Rheumatoid/diagnosis* ; Male ; Female ; Middle Aged ; Rheumatoid Factor/blood* ; Anti-Citrullinated Protein Antibodies/blood* ; Adult ; Quality of Life ; Prospective Studies ; Antirheumatic Agents/therapeutic use* ; Aged ; Peptides, Cyclic/immunology* ; Prednisolone/therapeutic use* ; Surveys and Questionnaires ; Severity of Illness Index ; Prognosis

Rheumatoid arthritis (RA), an autoimmune disease characterized by chronic inflammation of synovial tissue, is divided into two subtypes-anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. While the pathogenic mechanisms of ACPA-positive RA are well-understood, the etiology of ACPA-negative RA remains largely unknown. The association between RA and periodontitis (PD) has been observed since the early 1900s, with the two diseases sharing common genetic and environmental risk factors that lead to the progressive destruction of bone and connective tissue. However, the associations between PD and the two subtypes of RA differ. This comprehensive review aims to provide an updated understanding of the epidemiological association between RA and PD, explore potential pathogenic mechanisms linking the two diseases, and highlight the key distinctions between the subtypes of RA and their respective associations with PD. We also discuss the possibility of early intervention or the treatment of the two diseases. Ultimately, this review aims to provide valuable insights for future research in this field.
Humans ; Arthritis, Rheumatoid/complications* ; Periodontitis/complications* ; Anti-Citrullinated Protein Antibodies/immunology* ; Risk Factors