A comparison of vascular inflammation in psoriasis, rheumatoid arthritis, and healthy subjects by FDG-PET/CT: a pilot study.

OBJECTIVE: Psoriasis (PSO) and rheumatoid arthritis (RA) increase cardiovascular diseases (CVD) beyond traditional risk factors. Vascular inflammation has previously been demonstrated to be present in PSO and RA using [18F]-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) imaging. However, vascular inflammation has not been compared in these two disorders relative to a healthy reference population. Thus, vascular inflammation was quantitatively assessed in patients with PSO (n=10), RA (n=5), and healthy subjects (n=10) using FDG-PET/CT. METHODS: FDG-PET/CT mean standardized uptake value (SUVmean) was determined slice by slice within the ascending, aortic arch, descending thoracic, suprarenal abdominal, and infrarenal abdominal aorta, and the mean metabolic volumetric product (MVPmean) was then calculated for each aortic subsegment. Plasma lipids and metabolic and inflammatory markers were also assessed. RESULTS: CVD risk profiles were largely similar across groups. After adjustment for CV risk factors, regional aortic vascular inflammation based on MVPmean was elevated for both PSO (beta coefficients 0.31-1.47, p<0.001) and RA (beta coefficients 0.15-0.69, p<0.05) compared to healthy subjects. CONCLUSIONS: These observations using FDG-PET/CT to estimate vascular inflammation support epidemiological findings of premature atherosclerosis in PSO and RA. The use of FDG-PET/CT to investigate vascular inflammation across systemic inflammatory diseases warrants further examination in larger study populations.

Aortic vascular inflammation in psoriasis is associated with HDL particle size and concentration: a pilot study.

Psoriasis is a model Th1-mediated inflammatory disease associated with increased incidence of stroke and cardiovascular disease (CVD). The mechanism behind these associations is unknown, however abnormal HDL particle composition measured by nuclear magnetic resonance (NMR) spectroscopy has been shown to be associated with CVD. Using [18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT), a validated surrogate marker of CVD, we assessed whether HDL particle size and concentration were associated with vascular inflammation in patients with psoriasis. Patients with psoriasis were prospectively enrolled (439 aortic samples from 10 patients). Lipoprotein profiles using NMR spectroscopy were obtained and the relationship between vascular inflammation within the thoracic aorta by FDG-PET/CT was analyzed for association with lipoprotein particle characteristics. The plasma total cholesterol (206 mg/dL (IQR 154-229)), LDL (105 (90-161)), and triglyceride levels were within normal range (151 (94-191)) while HDL levels were low (28.9 (27.2-31.3)); however, the NMR profile demonstrated an atherogenic profile with increased small LDL and HDL particles. Total HDL particle concentration (p<0.001) and HDL particle size (p<0.001) were associated with decreased aortic inflammation, while concentration of small HDL particles was associated with increased inflammation (p<0.001). The association of total HDL particle concentration (ß -0.0113, p=0.002) and small HDL particle concentration (ß 0.026, p<0.001) with aortic inflammation persisted following adjustment for CVD risk factors. Total HDL particle concentration and small HDL particle concentration were associated with vascular inflammation within the thoracic aorta in psoriasis. These findings suggest that HDL particle characteristics may play an important role in psoriatic vascular inflammation and CVD.