Treatment recommendations of early rheumatoid arthritis (RA) suggest differential management of patients on the basis of prognostic factors. In this study we aimed to investigate the relationship between autoantibodies against a novel citrullinated fibrinogen peptide (anti-CFP), smoking status, clinical activity and therapeutic response in Cuban patients with early RA, receiving treatment with methotrexate in comparison to rheumatoid factor (RF), anti-cyclic citrullinated peptide of second generation (anti-CCP2) and anti-mutated citrullinated vimentin (anti-MCV). A 6-month prospective observational study was performed in 60 early RA patients at baseline and 6 months after receiving methotrexate. Baseline and outcome measures included disease activity score of 28 joints (DAS 28), simplified disease activity index (SDAI), anti-CFP antibodies, RF, anti-CCP2 and anti-MCV. Therapeutic response was determined using 20/50/70 American College of Rheumatology (ACR) response rates. DAS28 (p < 0.0001), SDAI (p < 0.0001) as well as titres of anti-CFP (p = 0.0481), anti-CCP2 (p = 0.0082), RF IgM (p = 0.0187) and RF IgA (p = 0.0252) decreased under therapy. Multivariate analyses showed association of final anti-CFP values with sex and smoking status (p = 0.0296). It is of note that anti-CFP antibodies were one of predictors for DAS 28 (p = 0.0072) SDAI (p < 0.0001) and ACR response (p = 0.0003) in multivariate models. Anti-CFP antibodies decrease in correspondence with clinical improvement after 6-month therapy and are associated with sex and smoking status. Moreover, baseline anti-CFP antibodies, using in combination with sex, smoking status and autoantibodies (anti-CCP2, anti-MCV or RF) seems to have clinical relevance for predicting clinical activity and therapeutic response.
Keywords: Antibodies; Clinical activity; Methotrexate; Rheumatoid arthritis; Smoking.