RESUMEN
OBJECTIVE: Subjects with SLE display an enhanced risk of atherosclerotic cardiovascular disease (CVD) that is not explained by Framingham risk. This study sought to investigate the utility of nuclear MR (NMR) spectroscopy measurements of serum lipoprotein particle counts and size and glycoprotein acetylation (GlycA) burden to predict coronary atherosclerosis in SLE. METHODS: Coronary plaque burden was assessed in SLE subjects and healthy controls using coronary CT angiography. Lipoproteins and GlycA were quantified by NMR spectroscopy. RESULTS: SLE subjects displayed statistically significant decreases in high-density lipoprotein (HDL) particle counts and increased very low-density lipoprotein (VLDL) particle counts compared with controls. Non-calcified coronary plaque burden (NCB) negatively associated with HDL subsets whereas it positively associated with VLDL particle counts in multivariate adjusted models. GlycA was significantly increased in SLE sera compared with controls. In contrast to high-sensitivity C reactive protein, elevations in GlycA in SLE significantly associated with NCB and insulin resistance (IR), though the association with NCB was no longer significant after adjusting for prednisone use. CONCLUSIONS: Patients with SLE display a proatherogenic lipoprotein profile that may significantly contribute to the development of premature CVD. The results demonstrate that NMR measures of GlycA and lipoprotein profiles, beyond what is captured in routine clinical labs, could be a useful tool in assessing CVD risk in patients with SLE.
RESUMEN
BACKGROUND: Systemic lupus erythematosus (SLE) is associated with enhanced risk of atherosclerotic cardiovascular disease not explained by Framingham risk score (FRS). Immune dysregulation associated to a distinct subset of lupus proinflammatory neutrophils (low density granulocytes; LDGs) may play key roles in conferring enhanced CV risk. This study assessed if lupus LDGs are associated with in vivo vascular dysfunction and inflammation and coronary plaque. METHODS: SLE subjects and healthy controls underwent multimodal phenotyping of vascular disease by quantifying vascular inflammation (18F-fluorodeoxyglucose-PET/CT [18F-FDG-PET/CT]), arterial dysfunction (EndoPAT and cardio-ankle vascular index), and coronary plaque burden (coronary CT angiography). LDGs were quantified by flow cytometry. Cholesterol efflux capacity was measured in high-density lipoprotein-exposed (HDL-exposed) radioactively labeled cell lines. Whole blood RNA sequencing was performed to assess associations between transcriptomic profiles and vascular phenotype. RESULTS: Vascular inflammation, arterial stiffness, and noncalcified plaque burden (NCB) were increased in SLE compared with controls even after adjustment for traditional risk factors. In SLE, NCB directly associated with LDGs and associated negatively with cholesterol efflux capacity in fully adjusted models. A neutrophil gene signature reflective of the most upregulated genes in lupus LDGs associated with vascular inflammation and NCB. CONCLUSION: Individuals with SLE demonstrate vascular inflammation, arterial dysfunction, and NCB, which may explain the higher reported risk for acute coronary syndromes. The association of LDGs and neutrophil genes with vascular disease supports the hypothesis that distinct neutrophil subsets contribute to vascular damage and unstable coronary plaque in SLE. Results also support previous observations that neutrophils may disrupt HDL function and thereby promote atherogenesis. TRIAL REGISTRATION: Clinicaltrials.gov NCT00001372FUNDING. Intramural Research Program NIAMS/NIH (ZIA AR041199) and Lupus Research Institute.
