AB0322 BIOMASS SMOKE EXPOSURE LINKED TO HIGHER ACPA LEVELS IN MEXICAN-MESTIZO RA-PATIENTS
Authors: Dionicio ángel Galarza-Delgado, Iris Jazmin Colunga-Pedraza, José Ramón Azpiri-López, Ileana Cecilia Reynosa-Silva, Raymundo Pineda, Karla Paola Cuéllar-Calderón, Marielva Castro-González, Carolina Marlene Martínez-Flores, Alberto Cárdenas
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Rheumatoid arthritis (RA) is a chronic, inflammatory, autoimmune disease of the joints. Current classification criteria for RA diagnosis requires the presence of either rheumatoid factor (RF) or anti-citrullinated protein antibodies (ACPA). These have also been linked to chronic air pollutants exposure, such as tobacco smoke and biomass fuel smoke. Patients with COPD and biomass exposure have higher levels of ACPA (1). Nearly 50% of the world's population still rely on biomass fuels for cooking, heating and industry, especially in low-income countries (2). <h3>Objectives</h3> To investigate the prevalence of biomass exposure in a cohort of Mexican-mestizo RA-subjects, and the effect of it in their RF and ACPA levels. <h3>Methods</h3> A cross-sectional, observational trial with RA-subjects that fulfilled the 2010 ACR/EULAR classification criteria, recruited at a rheumatology clinic in northeastern Mexico. Patient evaluation included a complete clinical history, somatometry, and blood samples to measure hs-CRP, RF isotypes (IgA, IgG, IgM) and ACPA. Biomass exposure was documented using the biomass exposure index (BEI), defined as: average hours exposed per day multiplied by years of exposure. Descriptive analysis was done using frequencies (%) and median values (q25-q75). Subjects were divided into 3 groups according to their BEI: non-exposed, BEI &lt;30 and BEI &gt;30. Comparisons were done by Chi-square and Kruskal-Wallis test and correlation by Spearman's rho test. <h3>Results</h3> A total of 285 subjects were included, 154 (54%) of them had history of exposure. Comparisons are shown in Table 1. A significant difference in age was found (p=0.006), this being caused by a difference between the BEI=0 and BEI &gt;30 groups (p&lt;0.001). We also found a higher prevalence of dyslipidemia and hypertension in subjects with a BEI &gt;30 (p&lt;0.05). A significant correlation between a rising BEI and a higher value of ACPA (rho=0.14, p=0.016) was found; this correlation was not found with any subtype of RF (p&gt;0.05). <h3>Conclusion</h3> In our cohort of Mexican-mestizo RA subjects, 54% had positive biomass exposure. Subjects with a BEI &gt;30 were older and had a higher prevalence of dyslipidemia and hypertension. A significant correlation was found between higher BEI index and a higher value of ACPA antibodies. <h3>References</h3> [1] Sigari N, et al. (2015). Anti-cyclic citrullinated peptide (CCP) antibody in patients with wood-smoke-induced chronic obstructive pulmonary disease (COPD) without rheumatoid arthritis. Rheumatology International. [2] Yang, DH, et al. (2014). Circulating anti-cyclic citrullinated peptide antibody in patients with rheumatoid arthritis and chronic obstructive pulmonary disease. Rheumatology International. <h3>Disclosure of Interests</h3> None declared