Th228 - To Quantify the Kinetics of the Degree of Inflammation by a Novel Quantitative in vivo Imaging Technique: PET Imaging Study in the CIA Mouse Model
Abstract Text: Hypothesis of this study was that as in the PET-CIA mouse model the degree of inflammation can be quantified so we should be able to determine the kinetics of the degree of changes in inflammation in longitudinal studies.
Arthritis was induced using bovine type II collagen in DBA/1J mice (n=30), out of which 20 mice developed arthritis on Day 28. The mice had PET imaging on the week 1st, 2nd, 3rd and 5th; that is imaging on the days 0, 28, 35, 42 and 56. The maximum 18F-FDG uptake (SUV score) was determined for the most severe joint in each mouse to generate a comprehensive PET score (PS). The median clinical score (CS) of the most affected limb increased with time to 2, 2, 3, 3.5 and 3 respectively on day 28, 32, 42 and 56. The PS SUV score on day 0 was 1.02. PS median values increased to 1.52 on day 28 (p < 0.05), 3.5 on day 35 (p < 0.05), 4.5 on day 42 (p < 0.05) and 3.5 on day 56 (p < 0.05). Our results confirm that the kinetics of the total inflammatory load can be quantified. Further on treating these mice with tofacitinib we could see significant therapeutic efficacy within the 1st week of therapy. Thus, this will be a novel tool for monitoring the inflammatory load and a unique tool to measure efficacy or resistance to therapies at an early stage. With time we are transferring these observations to quantify the degree of inflammation in human with RA and PsA.
