SAT0596 ASSOCIATIONS BETWEEN CIRCULATING LIPID MEDIATORS AND INCIDENT INFLAMMATORY ARTHRITIS IN AN ANTI-CITRULLINATED PROTEIN ANTIBODY POSITIVE POPULATION

Background:

Lipid mediators are endogenously derived from the metabolism of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) and have important roles in promoting and resolving inflammation in the body (1). Epidemiological studies have shown higher omega-3 PUFA status to be associated with a lower risk of both autoimmunity and progression to inflammatory arthritis (IA) (2,3).

Objectives:

To determine the association of lipid mediators with progression from rheumatoid arthritis (RA)-related autoimmunity to inflammatory arthritis (IA).

Methods:

We conducted a prospective cohort study using data from the Studies of the Etiologies of Rheumatoid Arthritis (SERA). SERA enrolled first-degree relatives (FDRs) of individuals with RA (FDR cohort) and individuals who screened positive for RA-related autoantibodies at health fairs (screened cohort). We followed 133 anti-CCP3.1 positive participants, of which 29 developed IA (22 classified as RA by 2010 ACR/EULAR criteria). We quantified lipid mediators from stored plasma samples via liquid chromatography tandem mass spectrometry methods validated against the collection and storage methods used in the study. A priori, we selected 5S-HETE, 15S-HETE and 17S-HDHA because they are precursors to leukotrienes, Lipoxin A4 and Resolvin D series lipid mediators, respectively. We fit Cox proportional hazard models for each lipid mediator as a time-varying covariate. For lipid mediators significantly associated with progression to IA we then examined IL-1β, IL-6, IL-8 and TNF-α (Bio-Plex Pro™ assay) as potential mediators of this relationship.

Results:

Higher plasma 5S-HETE levels were associated with an increased risk of incident IA after adjusting for age at baseline, cohort (FDR or screened), and shared epitope (SE) status (Table 1). The models examining 15S-HETE and 17S-HDHA had the same trend but did not reach statistical significance. We did not find evidence that the association between 5S-HETE and IA risk was mediated by the tested pro-inflammatory cytokines, suggesting a direct role for this lipid mediator in conversion to IA.

Table 1.

Hazard ratios and 95% confidence intervals of lipid mediator concentrations associated with IA, n=29 IA cases

Lipid mediatorCrudeAdjustedb5S-HETE2.10 (1.12, 3.92)2.41 (1.43, 4.07)15S-HETE1.61 (0.88, 2.93)1.52 (0.87, 2.65)17-HDHAa1.59 (0.68, 3.74)1.61 (0.72, 3.56)

adichotomized as <limit of detection (reference) or detected

bAdjusted for SE, age at baseline and cohort

Conclusion:

In a prospective cohort of anti-CCP positive individuals, higher circulating levels of 5S-HETE, an important precursor to pro-inflammatory leukotrienes, was associated with subsequent IA. Our findings highlight the potential pathologic and prognostic significance of these PUFA metabolites in inflammatory processes in pre-RA populations.

References:

[1]Serhan CN. Pro-resolving lipid mediators are leads for resolution physiology. Nature. 2014;510(7503):92-101.

[2]Gan RW, Bemis EA, Demoruelle MK, Striebich CC, Brake S, Feser ML, et al. The association between omega-3 fatty acid biomarkers and inflammatory arthritis in an anti-citrullinated protein antibody positive population. Rheumatology. 2017.

[3]Gan RW, Young KA, Zerbe GO, Demoruelle MK, Weisman MH, Buckner JH, et al. Lower omega-3 fatty acids are associated with the presence of anti-cyclic citrullinated peptide autoantibodies in a population at risk for future rheumatoid arthritis: a nested case-control study. Rheumatology. 2016;55(2):367-76.

Disclosure of Interests:

Kristen Polinski: None declared, Elizabeth Bemis: None declared, Kristen Demoruelle Grant/research support from: Pfizer, Jennifer Seifert: None declared, Tessa Crume: None declared, Fan Yang: None declared, William Robinson: None declared, Michael Clare-Salzler: None declared, Kevin Deane Grant/research support from: Janssen, Consultant of: Inova, ThermoFisher, Janseen, BMS and Microdrop, Michael Holers Shareholder of: AdMIRx, Grant/research support from: AdMIRx, Pfizer, Janssen R&D, Consultant of: AdMIRx, Janssen R&D, Celgene, Bristol-Myers Squibb, Jill Norris Grant/research support from: Janssen R&D, Pfizer, Consultant of: Celgene, BMS

Rationale and design for the community activation for prevention study (CAPs): A randomized controlled trial of community gardening

BACKGROUND

Engaging in health-promoting behaviors (e.g., healthy fruit- and vegetable-rich diet, physical activity) and living in supportive social and built environments are consistently and significantly associated with reductions in cancer, heart disease, diabetes, and other chronic diseases. Interventions to change diet and physical activity behaviors should aim to educate individuals, change the environments in which people live, work and recreate, improve access, availability, and affordability of healthy foods, and create safe places the facilitate active lifestyles. This trial will assess whether community gardening increases fruit and vegetable consumption and physical activity, improves social support and mental health, and reduces age-associated weight gain and sedentary time among a multi-ethnic, mixed-income population.

METHODS/DESIGN

A randomized controlled trial of community gardening began in Denver, Colorado in January 2017. Over 3 years, we will recruit 312 consenting participants on Denver Urban Gardens' waitlists and randomize them to garden or remain on the waitlist. At baseline (pre-gardening), harvest time, and post-intervention, study participants will complete three 24-hour dietary recalls, a 7-day activity monitoring period using accelerometry, a health interview and physical anthropometry.

DISCUSSION

This project addresses health-promoting behaviors among a multi-ethnic, mixed-income adult population in a large metropolitan area. If successful, this trial will provide evidence that community gardening supports and sustains healthy and active lifestyles, which can reduce risk of cancer and other chronic diseases.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03089177: Registered on 03/17/17.

Re-assessment of risk factors for sporadic Salmonella serotype Enteritidis infections: a case-control study in five FoodNet Sites, 2002-2003

Active surveillance for laboratory-confirmed Salmonella serotype Enteritidis (SE) infection revealed a decline in incidence in the 1990s, followed by an increase starting in 2000. We sought to determine if the fluctuation in SE incidence could be explained by changes in foodborne sources of infection. We conducted a population-based case-control study of sporadic SE infection in five of the Foodborne Diseases Active Surveillance Network (FoodNet) sites during a 12-month period in 2002-2003. A total of 218 cases and 742 controls were enrolled. Sixty-seven (31%) of the 218 case-patients and six (1%) of the 742 controls reported travel outside the United States during the 5 days before the case's illness onset (OR 53, 95% CI 23-125). Eighty-one percent of cases with SE phage type 4 travelled internationally. Among persons who did not travel internationally, eating chicken prepared outside the home and undercooked eggs inside the home were associated with SE infections. Contact with birds and reptiles was also associated with SE infections. This study supports the findings of previous case-control studies and identifies risk factors associated with specific phage types and molecular subtypes.