POS0482 WOOD SMOKE EXPOSURE IS ASSOCIATED WITH HIGHER ANTI-CCP ANTIBODY TITERS IN HISPANIC PATIENTS WITH RHEUMATOID ARTHRITIS
Authors: A. B. Rodriguez-Romero, D. Á. Galarza-Delgado, J. R. Azpiri-López, I. J. Colunga-Pedraza, N. Guajardo-Jauregui, S. Lugo-Perez, A. Cárdenas
Journal: Annals of the Rheumatic Diseases (2021)

Background: Wood smoke exposure is a risk factor for the development of chronic obstructive pulmonary disease (COPD), lung cancer and cardiovascular disease and it has also been linked to higher anti-CCP antibodies in patients with rheumatoid arthritis (RA) and COPD (1). Objectives: The objective of the present study is to report the correlation between anti-CCP, IgG, IgM and IgA rheumatoid factor (RF) to wood smoke exposure in patients with RA. Additionally, evaluate the impact of disease activity, biomass exposure, and disease duration on anti-CCP antibody levels. Methods: A cross-sectional, observational study was designed based on a cohort of Hispanic RA patients. All fulfilled the 2010 ACR/EULAR classification criteria for RA. Biomass smoke exposure was expressed using the biomass exposure index (BEI) calculated from the mean of exposed hours per day multiplied by the number of years exposed. Subjects were divided into two groups: those exposed to wood smoke with BEI ≥1 and subjects not exposed to wood smoke. They were matched by age, gender, and comorbidities. Anti-CCP antibodies and RF were measured by ELISA with cutoff points of &lt;5 U/mL and &lt;20 U/mL respectively. Results: A total of 318 subjects were included, 159 (50%) of them had a history of exposure to wood smoke. Anti-CCP antibody positivity was present in 102 (64.2%) with a median titer of 97.1 U/mL (1.7-198) in the RA exposed group, and in 89 (56%) with a median titer of 8.5 U/mL (1.1-145) in the RA non-exposed group. A significant difference was found in anti-CCP antibody titers between groups (p=0.003). (Table 1). Spearman’s rho showed a small but statistically significant correlation between BEI and anti-CCP antibody titers (rho= 0.170, p=0.002). Biomass exposure was independently related to higher anti-CCP antibody titers (B=35.4, p&lt;0.001). Conclusion: RA patients who were exposed to wood smoke had higher titers of anti-CCP antibodies than non-exposed RA patients. Furthermore, biomass exposure was shown to be independently related to higher titers of anti-CCP antibodies. References: [1]Fullerton DG, Bruce N, Gordon SB. Indoor air pollution from biomass fuel smoke is a major health concern in the developing world. Trans R Soc Trop Med Hyg. 2008;102(9):843-51. Table 1. Comparison of demographic, seropositivity and clinical characteristic between patients with RA exposed and matched non-exposed RA patients. Characteristics RA exposed (n=159 ) RA not exposed (n=159 ) p Age years, ± SD 56.7 ± 8.7 55.4 ± 8.1 NS Female, n (%) 148 (93.1) 148 (93.1) NS BEI years, median (p25-p75) 35 (15-90) 0 Disease duration years, median (p25-p75) 9 (3.5-15.1) 6.8 (2.8-14.6) NS DAS 28-CRP, median (p25-p75) 3.37 (2.11-4.4) 3.17 (2.09-4.2) NS Dyslipidemia, n (%) 50 (31.4) 43 (27) NS Hypertension, n (%) 55 (34.6) 48 (30.2) NS Diabetes Mellitus, n (%) 24 (15.1) 23 (14.5) NS Active smoking, n (%) 8 (5) 8 (5) NS Seropositivity Anti-CCP antibody positivity, n (%) 102 (64.2) 89 (56) 0.137 Anti-CCP antibody titers, median (p25-p75) 97.1 (1.7-198) 8.5 (1.1-145) 0.003 IgG RF positivity, n (%) 31 (19.5) 24 (15.1) 0.299 IgG RF titers, median (p25-p75) 5 (2-13) 4.9 (2-13) 0.529 IgM RF positivity, n (%) 136 (85.5) 126 (79.2) 0.141 IgM RF titers, median (p25-p75) 198 (41-200) 177 (28-200) 0.067 IgA RF positivity, n (%) 98 (61.6) 92 (57.9) 0.493 IgA RF titers, median (p25-p75) 52.9 (9.3-193) 33(5-159) 0.060 NS, non-significant; RA, rheumatoid arthritis; BMI, body mass index; BEI, biomass exposure index; DAS28-CRP, disease activity score using 28 joints-C-reactive protein; anti-CCP, anti-cyclic citrullinated peptide; RF, rheumatoid factor Disclosure of Interests: None declared