Performance of the PET vascular activity score (PETVAS) for qualitative and quantitative assessment of inflammatory activity in Takayasu's arteritis patients.

PURPOSE: To assess the performance of PET vascular activity score (PETVAS) in comparison with SUVmax, inflammatory biomarkers and ITAS-2010 score in a cohort of TAK patients. METHODS: Sixty-four PET/CT scans acquired from 54 TAK patients were analyzed. The inflammatory activity was qualitatively determined by physician's global assessment and quantitatively determined by ITAS-2010 score. SUVmax and PETVAS were acquired by consensus review. Levels of the inflammatory biomarkers C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and pentraxin-3 (PTX-3) were measured. Performance of the qualitative diagnoses and the quantitative correlation were, respectively, compared by receiver operating characteristic (ROC) curve and Spearman correlation coefficient. RESULTS: The biomarkers (CRP, ESR, PTX-3), PET uptake values (SUVmax, PETVAS), and ITAS-2010 scores were all significantly higher in active patients than in non-active ones. The area under the ROC curve and Youden Index of PETVAS and PTX-3 were higher than those of SUVmax, CRP, ESR, and ITAS-2010. PETVAS and PTX-3 resulted in a higher Spearman correlation coefficient with ITAS-2010 than other criteria, either among all patients or within the active group. Alteration trends of PETVAS and PTX-3 during follow-up showed a tighter correlation with clinical progression/remission assessment than other criteria. CONCLUSIONS: In TAK evaluation, PETVAS is superior for qualitative and quantitative assessment, compared with the regional SUVmax. Compared to CRP and ESR, inflammatory biomarker PTX-3 shows better qualitative performance and a higher correlation with PETVAS and ITAS-2010. These findings indicate that the use of PETVAS and PTX-3, instead of SUVmax and CRP/ESR, has potential advantages in the clinical evaluation of TAK.

Assessment of the Aging of the Brown Adipose Tissue by 18F-FDG PET/CT Imaging in the Progeria Mouse Model Lmna-/.

Brown adipose tissue (BAT) is an important energy metabolic organ that is highly implicated in obesity, type 2 diabetes, and atherosclerosis. Aging is one of the most important determinants of BAT activity. In this study, we used 18F-FDG PET/CT imaging to assess BAT aging in Lmna-/- mice. The maximum standardized uptake value (SUVMax) of the BAT was measured, and the target/nontarget (T/NT) values of BAT were calculated. The transcription and the protein expression levels of the uncoupling protein 1 (UCP1), beta3-adrenergic receptor (ß3-AR), and the PR domain-containing 16 (PRDM16) were measured by quantitative real-time polymerase chain reaction (RT-PCR) and Western blotting or immunohistochemical analysis. Apoptosis and cell senescence rates in the BAT of WT and Lmna-/- mice were determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and by CDKN2A/p16INK4a immunohistochemical staining, respectively. At 14 weeks of age, the BAT SUVMax and the expression levels of UCP1, ß3-AR, and PRDM16 in Lmna-/- mice were significantly reduced relative to WT mice. At the same time, the number of p16INK4a and TUNEL positively stained cells (%) increased in Lmna-/- mice. Collectively, our results indicate that the aging characteristics and the aging regulatory mechanism in the BAT of Lmna-/- mice can mimic the normal BAT aging process.