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ObjectivesCholesterol loading capacity (CLC) describes the ability of serum to deliver cholesterol to cells. It is linked to foam cell formation, a pivotal step in atherosclerotic plaque development. We evaluate the associations of CLC with coronary atherosclerosis presence, burden and cardiovascular risk in patients with rheumatoid arthritis (RA).MethodsCoronary atherosclerosis (any, high-risk low-attenuation plaque and obstructive plaque) was evaluated with CT angiography in 141 patients. Participants were prospectively followed for 6.0±2.4 years and cardiovascular events including cardiac death, myocardial infarction, unstable angina, stroke, claudication, revascularisation and hospitalised heart failure were recorded. CLC was quantified as intracellular cholesterol in human macrophages after incubation with patient serum.ResultsCLC was not linked to overall plaque presence or burden after adjustments for atherosclerotic cardiovascular disease (ASCVD) score, statin use and low-density lipoprotein cholesterol. However, CLC associated with presence and numbers of any, low-attenuation and obstructive plaques exclusively in biologic disease-modifying antirheumatic drugs (bDMARD) non-users (p for interaction ≤0.018). CLC associated with cardiovascular event risk overall after adjustments for ASCVD and number of segments with plaque (HR=1.76 (95% CI 1.16 to 2.67) per 1 SD increase in CLC, p=0.008). Additionally, bDMARD use modified the impact of CLC on event risk; CLC associated with events in bDMARD non-users (HR=2.52 (95% CI 1.36 to 4.65) per 1SD increase in CLC, p=0.003) but not users.ConclusionCLC was linked to long-term cardiovascular event risk in RA and associated with high-risk low attenuation and obstructive coronary plaque presence and burden in bDMARD non-users. Its prospective validation as a predictive biomarker may be, therefore, warranted.

ObjectivesThe marked cardiovascular risk in autoimmune diseases is only partly explained. The capacity of high-density lipoproteins (HDL) to promote cell cholesterol efflux is a property with a well-known anti-atherogenic significance, but is also involved in functional modulation of endothelial and immune cells. The aim of this work was to evaluate HDL functionality with respect to cell cholesterol efflux in rheumatoid arthritis (RA) and systemic lupus erythemathosus (SLE) patients.MethodsWe evaluated serum cholesterol efflux capacity (CEC) of apoB-depleted serum, which mainly reflects HDL activity, from 30 RA and 30 SLE patients, and from 30 healthy controls by radioisotopic ex-vivo systems discriminating between the specific pathways of cholesterol efflux.ResultsRA patients presented impairment of ATP-binding cassette G1-mediated CEC that correlated with disease activity. SLE patients showed a more complex pattern of modifications unrelated to disease activity, with marked reduction of ATP-binding cassette G1-mediated CEC and impairment of ATP-binding cassette A1-mediated CEC. The relationship between specific pathways of CEC values and serum total HDL differed between groups and there was no relationship with autoantibody profile or current therapy.ConclusionsCEC is impaired in RA and SLE, with a specific mechanism pattern in each disease not depending on serum HDL levels. These findings provide a new mechanism for the increased atherosclerotic risk in RA and SLE patients.

Background RA is associated with accelerated atherosclerosis. HDL in RA have reduced capacity to promote cell cholesterol efflux (CEC) while LDL have increased cholesterol loading capacity on macrophages (CLC). Inflammation and immune disturbances are among the mechanisms proposed. Anti-TNFa agents appear to reduce cardiovascular risk in RA, but their effects on serum lipid profile is variable. Objectives We studied modifications of lipoprotein function with respect to cell cholesterol trafficking after adalimumab therapy in RA. Methods Serum was drawn from 56 patients with RA, 34 treated with methotrexate (MTX), 22 starting with adalimumab in addition to ongoing MTX (MTX/ADA), before and after 6 weeks and 6 months of treatment. We measured: serum lipid profile; CLC with cholesterol measurement by fluorimetric technique; CEC with radioisotopic technique. Results HDL, LDL and total cholesterol serum levels increased in the MTX group after treatment, while HDL levels only increased in the MTX/ADA group. CLC significantly decreased after treatment in the MTX/ADA group only (mean ± SE, 7.16±0.28 vs 7.92±0.48 mg cholesterol/mg protein, p Conclusions Adalimumab addition to MTX treatment results in decreased cell cholesterol loading serum capacity and slight improvement in HDL promotion of cell cholesterol efflux, both potentially inhibiting foam cell formation. These effects may be especially relevant in RA patients with aggressive disease needing anti-TNFa, particularly prone to accelerated atherosclerosis. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.2441