Linking Power Doppler Ultrasound to the Presence of Th17 Cells in the Rheumatoid Arthritis Joint

Power Doppler ultrasound (PDUS) is increasingly used to assess synovitis in Rheumatoid Arthritis (RA). Prior studies have shown correlations between PDUS scores and vessel counts, but relationships with T cell immunopathology have not been described.PBMC were isolated from healthy controls (HC) or RA patients and stimulated ex vivo with PMA and ionomycin for 3 hours in the presence of Golgistop. Paired synovial fluid (SF) or synovial tissue (ST) were analysed where available. Intracellular expression of IL-17, IFNgamma, and TNFalpha by CD4+ T cells was determined by flow cytometry. Synovial blood flow was evaluated by PDUS signal at the knees, wrists and metacarpophalangeal joints of RA patients. Serum, SF and fibroblast culture supernatant levels of vascular endothelial growth factor-A (VEGF-A) were measured by ELISA. The frequency of IL17+IFNgamma-CD4+ T cells (Th17 cells) was significantly elevated in peripheral blood (PB) from RA patients vs. HC (median (IQR) 0.5 (0.28-1.59)% vs. 0.32 (0.21-0.54)%, p = 0.005). Th17 cells were further enriched (mean 6.6-fold increase) in RA SF relative to RA PB. Patients with active disease had a higher percentage of IL-17+ T cells in ST than patients in remission, suggesting a possible role for Th17 cells in active synovitis in RA. Indeed, the percentage of Th17 cells, but not Th1, in SF positively correlated with CRP (r = 0.51, p = 0.04) and local PDUS-defined synovitis (r = 0.61, p = 0.002). Furthermore, patients with high levels of IL-17+CD4+ T cells in SF had increased levels of the angiogenic factor VEGF-A in SF. Finally, IL-17, but not IFNgamma, increased VEGF-A production by RA synovial fibroblasts in vitro.Our data demonstrate a link between the presence of pro-inflammatory Th17 cells in SF and local PDUS scores, and offer a novel immunological explanation for the observation that rapid joint damage progression occurs in patients with persistent positive PDUS signal

Development of a freehand three-dimensional radial endoscopic ultrasonography system

Oesophageal cancer is an aggressive malignancy with an overall five-year survival of 5-10% and two-thirds of patients have irresectable disease at diagnosis. Accurate staging of oesophageal cancer is important as survival closely correlates with the stage of the tumour, nodal involvement and presence of metastases (TNM staging). Endoscopic ultrasonography (EUS) is currently the most reliable modality for providing accurate T and N staging. Depending on findings of the staging, various treatment options including endoscopic, oncological, and surgical treatments may be performed. It was theorised that the development of three-dimensional radial endoscopic ultrasonography would reduce the operator dependence of EUS and provide accurate dimensional and volume measurements to aid planning and monitoring of treatment. This thesis investigates the development of a three dimensional endoscopic ultrasound technique that can be used with the radial echoendoscopes. Various agar-based tissue mimicking material (TMM) recipes were characterised using a scanning acoustic macroscope to obtain the acoustic properties of attenuation, backscatter and speed of sound. Using these results, a number of endoscopic ultrasound phantoms were developed for the in-vitro investigation and evaluation of 3D-EUS techniques. To increase my understanding of EUS equipment, the imaging and acoustic properties of the EUS endoscopes were characterised using a pipe phantom and a hydrophone. The dual ‘single element’ mechanical and ‘multi-element’ electronic echoendoscopes were investigated. Measured imaging properties included dead space, low contrast penetration, and pipe length. The measured acoustic properties included transmitted beam plots, active working frequency and peak pressures. Three-dimensional ultrasound techniques were developed for specific application to EUS. This included the study of positional monitoring systems, reconstruction algorithms and measurement techniques. A 3D-EUS system was developed using a Microscribe positional arm and frame grabber card, to acquire the 3D dataset. A Matlab 3D-EUS toolbox was written to reconstruct and analyse the volumes. The 3D-EUS systems were evaluated on the EUS phantom and in clinical cases. The usefulness of the 3D-EUS systems was evaluated in a cohort of patients, who were routinely investigated by conventional EUS for a variety of upper gastrointestinal pathology. 3D-EUS accurately staged early tumours and provided the necessary anatomical information to facilitate treatment. With regards to more advanced tumours, 3D-EUS was more accurate than EUS in T and N staging. 3D-EUS gave useful anatomical details in a variety of benign conditions such as varicies and GISTs.EThOS - Electronic Theses Online ServiceGBUnited Kingdo