RT Journal Article
SR Electronic
T1 Omega-3 fatty acids are associated with a lower prevalence of autoantibodies in shared epitope-positive subjects at risk for rheumatoid arthritis
JF Annals of the Rheumatic Diseases
JO Ann Rheum Dis
FD BMJ Publishing Group Ltd and European League Against Rheumatism
SP 147
OP 152
DO 10.1136/annrheumdis-2016-209154
VO 76
IS 1
A1 Ryan W Gan
A1 M Kristen Demoruelle
A1 Kevin D Deane
A1 Michael H Weisman
A1 Jane H Buckner
A1 Peter K Gregersen
A1 Ted R Mikuls
A1 James R O'Dell
A1 Richard M Keating
A1 Tasha E Fingerlin
A1 Gary O Zerbe
A1 Michael J Clare-Salzler
A1 V Michael Holers
A1 Jill M Norris
YR 2017
UL http://ard.bmj.com/content/76/1/147.abstract
AB Objectives Previously, we found that omega-3 fatty acids (n-3 FAs) were inversely associated with anti-cyclic citrullinated peptide (anti-CCP) positivity in participants at risk for future rheumatoid arthritis (RA). We investigated whether n-3 FAs were also associated with rheumatoid factor (RF) positivity and whether these associations were modified by shared epitope (SE) positivity.Methods The Studies of the Etiology of RA (SERA) cohort includes RA-free participants who are at increased risk for RA. We conducted a nested case–control study (n=136) to determine the association between RF and anti-CCP2 positivity and n-3 FA percentage in erythrocyte membranes (n-3 FA% in red blood cells (RBCs)). Additionally, in the baseline visit of the SERA cohort (n=2166), we evaluated the association between reported n-3 FA supplement use and prevalence of RF and anti-CCP2. We assessed SE positivity as an effect modifier.Results In the case–control study, increasing n-3 FA% in RBCs was inversely associated with RF positivity in SE-positive participants (OR 0.27, 95% CI 0.10 to 0.79), but not SE-negative participants. Similar associations were seen with anti-CCP positivity in SE-positive participants (OR 0.42, 95% CI 0.20 to 0.89), but not SE-negative participants. In the SERA cohort at baseline, n-3 FA supplement use was associated with a lower prevalence of RF positivity in SE-positive participants (OR 0.32, 95% CI 0.12 to 0.82), but not SE-negative participants; similar but non-significant trends were observed with anti-CCP2.Conclusions The potential protective effect of n-3 FAs on RA-related autoimmunity may be most pronounced in those who exhibit HLA class II genetic susceptibility to RA.