AB0133 Blood Transfusion (BT) is Associated with the Risk of Developing Rheumatoid Arthritis (RA) and with Disease Severity: Data from ESPOIR Cohort

Background Both environmental or lifestyle factors, including smoking, overweight and periodontal disease, were found to be associated with an increased risk for developing rheumatoid arthritis (RA). Few studies suggested that blood transfusions (BT) could be another potential risk factor for RA. Although the underlying pathophysiological mechanism is unclear, it is well known that BT leads to significant modifications in recipient immune system. Objectives The aim of this study was to estimate the prevalence of BT history in a cohort of patients with early RA, and to compare the course of the disease between transfused and non-transfused RA patients in the cohort. Methods The ESPOIR cohort is a French national prospective cohort that included patients with early arthritis prone to develop into RA. History of BT before inclusion in the cohort was searched for each patient with a confirmed diagnosis of RA after five-year follow-up in the cohort. A standardized prevalence ratio (SPR) was determined to evaluate the over-risk of BT past history in RA patients compared to age and sex matched general population. Clinical characteristics of RA were compared at inclusion and after five years of follow-up between BT recipients and non-recipients. Results Among the 813 patients included in the cohort, 705 had a confirmed diagnosis of RA after five years of follow-up. Among assessable patients, 10.5% (72/686) had a past history of BT at inclusion in the cohort. For age and sex-matched general population, the prevalence of BT is about 0.3%, leading to a SPR of 35 (95%CI: 27.4 – 44). The median time between BT and onset of arthritis was 25.5 years (IQR: 16 – 33). Furthermore, patients with history of BT were preferentially ACPA-negative (75.0% [54/72] for BT recipients vs. 53.2% [327/614] for non-recipients; p