SAT0692 Breastfeeding is not associated with anti-citrullinated antibodies development in individuals at risk for rheumatoid arthritis. (12th June 2018) - Alpizar-Rodriguez, D.
Abstract : Background: ' Systemic autoimmunity associated with rheumatoid arthritis' (RA), is a pre-clinical stage preceding the onset of clinical RA, characterised by the presence of autoantibodies, such as anti-citrullinated protein antibodies (ACPA) or anti-carbamylated protein antibodies (antiCarP). Breastfeeding has been proposed as a protective factor for RA development, 1 but there are some controversies. 2 To establish the causal role of a putative risk factor, longitudinal studies are needed, in particular in the pre-stages of RA development. Objectives: To s tudy the association between breastfeeding and the development of systemic autoimmunity associated with RA. Methods: This ongoing prospective study includes individuals genetically at risk of developing RA, namely first-degree relatives of RA patients (RA-FDR). Individuals without clinical evidence of RA were enrolled, and assessed yearly clinically and biologically. We included all RA-FDR women with available ACPA status (anti-CCP 2, 3.1 or 3.0) and information about breastfeeding. The primary outcome was ACPA positivity. The exposure of interest was breastfeeding and duration of breastfeeding (categorised as 0, 1–7 and ≥7 months). The presence of antiCarP was a secondary outcome. We used logistic regression to analyse univariable and multivariable associations. Results: A total of 882 women were included, of which 57 (6%) were ACPA positive. The characteristics of ACPA positive and negative participants were balanced, except for an older age in ACPA positives (median 52 versus 45 years; table 1). In the univariable analysis, ACPA positivity was not significantly associated with breastfeeding (OR 1.5, p=0.16) or with breastfeeding duration (OR=1.8, p=0.14). In the multivariable analysis adjusted by age, smoking, number of pregnancies and years of education, there was a weak, but not significant, association between breastfeeding for more than 7 months and ACPA positivity (OR 2.16, p=0.10). Among 728 women with available antiCarP results, 70 (10%) were positive, of which 27 (40%) breastfed. Breastfeeding for more than 7 months was not significantly associated with antiCarP in univariable or multivariable analyses (OR 1.3, p=0.52 and OR 1.9, p=0.16, respectively). Conclusions: Among women at risk of RA, breastfeeding was not associated with the presence of ACPA or antiCarP. Our results do not support a protective role of breastfeeding in the development of systemic autommunity associated with RA. References: [1] Orellana C, et al. Ann Rheum Dis2017;76:1845–52. [2] Berglin E, et al. Scand J Rheumatol2010;39:454 -60. Disclosure of Interest: None declared