Pregnancy loss and the risk of rheumatoid arthritis in Chinese women: findings from the China Kadoorie biobank

Abstract

Considering the female preponderance of rheumatoid arthritis (RA), and disease onset typically after the reproductive years, pregnancy and childbirth may play a role in the aetiology of the disease. Adverse outcomes of pregnancy have been found to precede the diagnosis of autoimmune diseases, including RA, but the evidence is scant and inconsistent. Therefore, we investigate whether pregnancy loss is associated with the risk of RA in Chinese women. Data from the China Kadoorie Biobank, conducted by the University of Oxford and the Chinese Centre for Disease Control and Prevention, of 299,629 Chinese women who had been pregnant were used. Multivariable logistic regression and stratified analyses were employed to analyse the association between types of pregnancy loss with the risk of RA. Pregnancy loss was significantly associated with increased risk of RA (OR 1.12, 95% CI 1.06–1.18), specifically, spontaneous (OR 1.11, 95% CI 1.03–1.20) and induced abortions (OR 1.11, 95% CI 1.06–1.17). There was no significant association between stillbirth and the risk of RA (OR 1.07, 95% CI 0.97–1.18). The risk of developing RA increases with the number of pregnancy losses: one loss confers an OR of 1.09 (95% CI 1.03–1.16), two an OR of 1.13 (95% CI 1.05–1.20), three or more an OR of 1.19 (95% CI 1.10–1.28) and OR of 1.06 (95% CI 1.03–1.08) for each additional. Spontaneous and induced abortions are associated with an increased risk of RA in Chinese women.

Determination of the Predictive Roles and Potentially Pathogenic Antigen Epitopes of α-Enolase Related to the Development of Miscarriage in Females with Autoimmune Thyroiditis

“…ENO1Ab expression was exhibited in patients with some autoimmune and inflammatory disorders at different positive rates, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS), severe asthma, membranous nephropathy, and primary sclerosing cholangitis [ 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. In fact, some of those diseases (e.g., RA, SLE, and APS) mentioned above have been reported as risk factors for spontaneous abortion [ 32 , 33 , 34 ]. Moreover, ENO1Ab has been found to be an important anti-trophoblast antibody; highly expressed in patients with unexplained recurrent miscarriages.…”

“…The serum expression patterns of 18 predicted ENO1 epitopes still need to be examined in a larger-sample study using both intact and mutant epitope peptides. Thirdly, serum ENO1Ab expression has been found in some other disorders (e.g., APS, RA, and SLE), which are also suggested as risk factors for miscarriage [ 31 , 32 , 33 , 34 ]. Although we had excluded patients with a known personal history of other autoimmune and inflammatory disorders, we admit that we did not test those other non-organ specific autoantibodies associated with spontaneous abortion in this study, and we did not analyze the synergistic or additive actions between ENO1Ab and other NOSA, which will be performed in the future.…”