Proudman, S.Cleland, L.Metcalf, R.Sullivan, T.Spargo, L.James, M.2015-09-172015-09-172015British Journal of Nutrition, 2015; 114(06):885-8900007-11451475-2662http://hdl.handle.net/2440/94434A randomised controlled trial (RCT) of high-dose v. low-dose fish oil in recent-onset rheumatoid arthritis (RA) demonstrated that the group allocated to high-dose fish oil had increased remission and decreased failure of disease-modifying anti-rheumatic drug (DMARD) therapy. This study examines the relationships between plasma phospholipid levels of the n-3 fatty acids in fish oil, EPA and DHA, and remission and DMARD use in recent-onset RA. EPA and DHA were measured in blood samples from both groups of the RCT. The data were analysed as a single cohort, and Cox proportional hazards models were used to examine relationships between plasma phospholipid (PL) EPA and DHA and various outcome measures. When analysed as a single cohort, plasma PL EPA was related to time to remission, with a one unit increase in EPA (1% total fatty acids) associated with a 12% increase in the probability of remission at any time during the study period (hazard ratio (HR)=1·12; 95% CI 1·02, 1·23; P=0·02). Adjustment for smoking, anti-cyclic citrullinated peptide antibodies and 'shared epitope' HLA-DR allele status did not change the HR. Plasma PL EPA, adjusted for the same variables, was negatively related to time to DMARD failure (HR=0·85; 95% CI 0·72, 0·99; P=0·047). The HR for DHA and time to remission or DMARD failure were similar in magnitude to those for EPA, but not statistically significant. Biomarkers of n-3 status, such as plasma PL EPA, have the potential to predict clinical outcomes relevant to standard drug treatment of RA patients.en© The Authors 2015Fish oil; eicosapentaenoic acid; docosahexaenoic acid; arthritis; nutritional immunologyJournal article003003391410.1017/s00071145150027180003613806000062-s2.0-84940975324207327Proudman, S. [0000-0002-3046-9884]Sullivan, T. [0000-0002-6930-5406]James, M. [0000-0002-4918-2998]