Objectives Reverse cholesterol transport (RCT) is a major antiatherogenic function of high density lipoprotein (HDL). In the current work, the authors evaluated whether the RCT capacity of HDL from rheumatoid arthritis (RA) patients is impaired when compared to healthy controls. Methods HDL was isolated from 40 patients with RA and 40 age and sex matched healthy controls. Assays of cholesterol efflux, HDL’s antioxidant function and paraoxanase-1 (PON-1) activity were performed as described previously. Plasma myeloperoxidase (MPO) activity was assessed by a commercially available assay. Results Mean cholesterol efflux capacity of HDL was not significantly different between RA patients (40.2%±11.1%) and controls (39.5%±8.9%); p=0.75. However, HDL from RA patients with high disease activity measured by a disease activity score using 28 joint count (DAS28>5.1), had significantly decreased ability to promote cholesterol efflux compared to HDL from patients with very low disease activity/clinical remission (DAS28<2.6). Significant correlations were noted between cholesterol efflux and the DAS28 (r=−0.39, p=0.01) and erythrocyte sedimentation rate, (r=−0.41, p=0.0009). Higher plasma MPO activity was associated with worse HDL function (r=0.41/p=0.009 (antioxidant capacity); r=0.35, p=0.03 (efflux)). HDL’s ability to promote cholesterol efflux was modestly but significantly correlated with its antioxidant function (r=−0.34, p=0.03). Conclusions The cholesterol efflux capacity of HDL is impaired in RA patients with high disease activity and is correlated with systemic inflammation and HDL’s antioxidant capacity. Attenuation of HDL function, independent of HDL cholesterol levels, may suggest a mechanism by which active RA contributes to increased cardiovascular (CV) risk.

Objective. To characterize the antiinflammatory function of high-density lipoprotein (HDL) in patients with rheumatoid arthritis (RA) and to identify specific differences in HDL-associated proteins and enzymes that distinguish proinflammatory HDL from normal, antiinflammatory HDL.Methods. We studied 132 RA patients. The antiinflammatory function of HDL was assessed by a cellfree assay, and proinflammatory HDL was defined by an HDL inflammatory index >1. Plasma and HDLassociated protein levels of apolipoprotein A-I (Apo A-I), haptoglobin, hemopexin, hemoglobin, and myeloperoxidase (MPO) were measured by direct and sandwich enzyme-linked immunosorbent assays, respectively. Lecithin:cholesterol acyltransferase (LCAT) activity was measured by a commercially available assay.Results. Age, disease activity, the presence of erosive disease, non-Caucasian race, and smoking were significantly associated with proinflammatory HDL on multivariate analysis. Patients with proinflammatory HDL had higher measures of systemic inflammation, and a significant correlation was observed between RA disease activity (using the Disease Activity Score in 28 joints) and the HDL inflammatory index (r ‫؍‬ 0.54, P < 0.0001). Compared with patients with antiinflammatory HDL, patients with proinflammatory HDL had significantly higher levels of haptoglobin, hemoglobin, Apo A-I, and MPO associated with HDL (P < 0.05 for all comparisons except MPO, which was P ‫؍‬ 0.05). LCAT activity was lowest in patients with proinflammatory HDL, but was also significantly reduced in RA patients with antiinflammatory HDL as compared with healthy controls (P ‫؍‬ 0.001).Conclusion. Proinflammatory HDL in this RA patient cohort was associated with active disease and an altered protein cargo as compared with antiinflammatory HDL in RA patients and in healthy controls. The antiinflammatory function of HDL was inversely correlated with systemic inflammation in RA patients and may warrant further investigation as a mechanism by which active RA increases cardiovascular morbidity and mortality.Premature cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with

Objective To utilize proteomic analysis to identify protein biomarkers associated with pro-inflammatory HDL in patients with active rheumatoid arthritis. Methods Liquid chromatography-mass spectrometry (LC-MS) was used to analyze proteins associated with immunoaffinity purified HDL from plasma of two sets of RA patients carrying distinct HDL (anti- or pro-) inflammatory properties. Proteins were fractionated by Offgel electrophoresis and analyzed by LC-MS/MS equipped with a high capacity high performance liquid chromatography chip (HPLC-Chip) incorporating C18 reverse phase trapping and analytical columns. Sandwich enzyme-linked immunosorbent assays were used to validate select HDL-associated proteins in a second RA cohort. Results Seventy-eight proteins were identified in the HDL complexes. Twelve proteins were significantly increased in RA patients with pro-inflammatory HDL compared to RA patients with anti-inflammatory HDL. These proteins included acute phase proteins, including apolipoprotein J, fibrinogen, haptoglobin, serum amyloid A, and complement factors (B, C3, C9). Four of the proteins associated with HDL were validated in a second RA cohort. Conclusion Pro-inflammatory HDL in patients with RA contains a significantly altered proteome including increased amounts of acute phase proteins and proteins involved in the complement cascade. These findings suggest that HDL is significantly altered in the setting of chronic inflammation from active RA with resultant loss of its anti-inflammatory function. The characterization of the biomarkers reported here may identify novel molecular connections that contribute to the higher risk of CVD in RA patients.

Objective Abnormal function of high density lipoprotein (HDL) has been implicated as a potential mechanism for the increased cardiovascular disease (CVD) in patients with rheumatoid arthritis. The current work evaluated changes in HDL function and HDL-associated proteins over two years of follow-up in early RA patients receiving either methotrexate (MTX) monotherapy or combination therapies in the Treatment of Early Rheumatoid Arthritis (TEAR) trial. Methods The anti-oxidant capacity of HDL, paraoxonase 1 (PON-1) activity, HDL-associated haptoglobin (HDL-Hp), HDL-associated apolipoprotein AI (HDL-apoA-I), and myeloperoxidase (MPO) levels were measured in 550 TEAR participants at 4 time points (0 [pre-treatment], 24, 48, and 102 weeks). Repeated measures analysis was performed using mixed effect linear models with autoregressive covariate structure to model the within-subject covariance over time. Results Mixed effect models controlling for traditional CV risk factors, treatment regimen, prednisone use, and statin use demonstrated significant associations of RA disease activity measured by the disease activity score with 28 joint count (DAS28), erythrocyte sedimentation rate (ESR), or C-reactive protein (CRP) with the HDL function profile over time. Specifically, decreases in RA disease activity over time were associated with increases in PON1 activity and HDL-apoA-I levels, and decreases in the HDL inflammatory index (HII), MPO, and HDL-Hp. Conclusion Decreases in disease activity in early RA patients treated with MTX, MTX + etanercept, or triple therapy in the TEAR trial were associated with improvements in the HDL function profile. Additional work is warranted to evaluate abnormal HDL function as a potential mechanism and therapeutic target for CV risk in patients with RA.

Objective To investigate the relationship of genetic and biochemical determinants of paraoxonase 1 activity to carotid plaque as a surrogate marker of cardiovascular (CV) risk in patients with rheumatoid arthritis (RA). Methods The relationships between paraoxonase 1 activity, PON1 genotype (for the functional polymorphism at position 192), and carotid plaque presence were determined in 168 RA patients. After an overnight fast, blood was collected for lipoprotein analysis, and paraoxonase 1 activity was measured using paraoxon as the substrate. The PON1 Q192R genotype was determined for all patients. Lipoprotein cholesterol levels, traditional CV risk factors, medication use, and RA disease characteristics were assessed for all patients. Results Paraoxonase 1 activity values in the RA patients were highest for the RR genotype, intermediate for the QR genotype, and lowest for the QQ geno-type (P < 0.0001). Compared to patients with either the QQ genotype or the QR genotype, patients with the RR genotype demonstrated decreased risk of carotid plaque on multivariate analysis, controlling for traditional CV risk factors, high-sensitivity C-reactive protein levels, prednisone use, and cholesterol-lowering medication use (P < 0.05). Additional multivariate logistic regression analysis controlling for the above factors also revealed a significant association of plasma paraoxonase 1 activity with carotid plaque in RA patients. Lower plasma paraoxonase 1 activity was associated with increased risk of carotid plaque (P < 0.05). Conclusion The current findings suggest a relationship of the genetic determinants and activity of paraoxonase 1 to CV risk in RA patients, as assessed by the presence or absence of carotid plaque. Further CV outcome studies are warranted to validate the utility of paraoxonase 1 as a biomarker of CV risk in patients with RA.