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

Activated and deactivated sintering of hydroxyapatite adsorbent using metallic additives

This work is part of a series of studies dealing with the evaluation of the effects of major elements of solid waste, especially metallic oxides, nitrates, sulfates and chlorides on the sintering and the densification of calcium hydroxyapatite Ca(PO) (OH) ,(Ca-HA) adsorbent. Ca-HA is a promising compound for adsorption and immobilisation of heavy metals from soils, incinerator fly ashes and hazardous industrial wastes. The immobilisation of heavy metals by Ca-HA increases significantly by calcination at temperatures ranging from 650°C to 900°C. The effects of chloride salts of potassium (KCI) and zinc (ZnCl ) as well as lead oxide (PbO) and lead nitrate [Pb(NO)] on sintering and densification of Ca-HA were studied using specific surface area changes, and dynamics measurements methods such as Thermomechanical Analyser (for shrinkage studies) and Environmental Scanning Electron Microscopy (ESEM). The addition of KCI, PbO and Pb(NO) (2% w/w) activated the sintering process by bringing a swift reduction in surface area, and lowering the densification temperature. However, a low final densification was achieved. On the other hand, the addition of 2% of ZnCl deactivated the sintering process by slowing down the densification process and raising the densification temperature. However, the reduction of surface area was comparable to that of Ca-HA