title: Hormonal replacement therapy may reduce the risk for RA in women with early arthritis who carry HLA-DRB1 *01 and/or *04 alleles by protecting against the production of anti-CCP: results from the ESPOIR cohort.
abstract: OBJECTIVE
  To assess the effect of reproductive factors, especially hormone replacement therapy (HRT) and its interaction with HLA-DRB1 *01 and/or *04 alleles on the diagnosis of rheumatoid arthritis (RA) and the presence of anti-cyclic citrullinated peptide (CCP) antibodies in women included in the ESPOIR cohort (early arthritis cohort).
  
  
  METHODS
  568 patients were included in the analyses, which were performed using logistic regression.
  
  
  RESULTS
  HRT reduced the risk of RA due to the HLA-DRB1 *01 and/or *04 alleles from OR 1.88 (95% CI 1.32 to 2.68, p<0.000) for HLA-DRB1 *01 and/or *04 alleles alone to OR 1.07 (95% CI 0.51 to 2.26, p=0.85) in women with HLA-DRB1 *01 and/or *04 alleles who received HRT. One explanation might be the protective effect of HRT on the presence of anti-CCP antibodies (OR 0.43, 95% CI 0.24 to 0.77, p<0.006). Other reproductive factors such as the number of pregnancies, menopause and age at menopause, age at menarche and a history of pregnancy with poor outcome were not associated with the diagnosis of RA and the presence of anti-CCP antibodies.
  
  
  CONCLUSIONS
  HRT may reduce the risk of RA due to HLA-DRB1 *01 and/or *04 alleles by protecting against the production of anti-CCP antibodies.
authors.affiliation: Paris Descartes University, Medicine Faculty UPRES-EA 4058 APHP, Hôpital Cochin, Service de Rhumatologie B, rue du faubourg Saint-Jacques, Paris, France. carinesalliot@cch.aphp.fr
authors.forename: Carine
authors.initials: C
authors.lastname: Salliot
authors.forename: Claire
authors.initials: C
authors.lastname: Bombardier
authors.forename: Alain
authors.initials: A
authors.lastname: Saraux
authors.forename: Bernard
authors.initials: B
authors.lastname: Combe
authors.forename: Maxime
authors.initials: M
authors.lastname: Dougados
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000276:immunology / Q000517:prevention & control*; D001323:Autoantibodies / Q000096:biosynthesis*; D018450:Disease Progression; D015914:Estrogen Replacement Therapy; D005260:Female; D020022:Genetic Predisposition to Disease; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006801:Humans; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C497841:HLA-DRB1*01 antigen; C527195:HLA-DRB1*04 antigen; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide