title: Epidemiology: Interpreting studies of interactions between RA risk factors.
abstract: Interactions between HLA and PTPN22 genotypes and smoking have been implicated in overall susceptibility to rheumatoid arthritis as well as the incidence of particular disease phenotypes in case-control and case-only studies. As recent epidemiological evidence shows, deciphering these interactions demands consideration of the analytical approach used.
authors.affiliation: Section of Clinical Sciences, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA. ekarlson@partners.org
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Karlson
authors.forename: Karen H
authors.initials: KH
authors.lastname: Costenbader
mesh_terms: D001172:Arthritis, Rheumatoid / Q000235:genetics*; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D054596:Protein Tyrosine Phosphatase, Non-Receptor Type 22 / Q000235:genetics*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*
chemical_list: D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C516765:PTPN22 protein, human; D054596:Protein Tyrosine Phosphatase, Non-Receptor Type 22