Related Experiment Videos
Elevated synovial expression of triggering receptor expressed on myeloid cells 1 in patients with septic arthritis or
C E Collins1, D T La, H-T Yang
1Division of Rheumatology, University of Southern California Keck School of Medicine, Los Angeles, CA 90033, USA.
Objective:
To determine whether synovial expression of triggering receptor expressed on myeloid cells 1 (TREM-1) is upregulated in patients with distinct types of inflammatory or non-inflammatory arthritis.
Methods:
Synovial fluid (SF) samples were analysed for levels of soluble TREM-1 (sTREM; n = 132), tumour necrosis factor alpha (TNFalpha, n = 78) and leucocyte TREM-1 messenger RNA (n = 48). Synovial tissue from four rheumatoid arthritis (RA) patients, two patients with Crohn's-associated arthritis, one patient with ankylosing spondylitis and one patient with osteoarthritis were examined for TREM-1 expression by immunohistology, and three of the RA samples were also analysed by Western blotting.
Results:
Synovial fluid sTREM-1 levels in septic arthritis and RA were similar to each other and were each greater than those in gouty arthritis, non-septic/non-RA inflammatory arthritis and non-inflammatory arthritis. Synovial fluid TNFalpha and sTREM-1 levels correlated with each other, and sTREM-1 and leucocyte TREM-1 mRNA levels each correlated with SF leucocyte counts. TREM-1 in RA was expressed in situ in synovial tissue by cells of myelomonocytic lineage but was not detectably expressed in control osteoarthritis synovial tissue.
Conclusions:
Synovial TREM-1 expression is increased in septic arthritis and RA. In patients with acute inflammatory arthritis, elevated SF sTREM-1 levels may point the clinician to a diagnosis of septic arthritis or RA. In RA patients, targeting TREM-1 may have therapeutic benefits by reducing local proinflammatory cytokine and chemokine release.
Related Concept Videos
T Cell Types and Functions
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
The JAK-STAT Signaling Pathway
Acute Inflammation I: Inflammatory Response
Rheumatic Heart Disease II: Clinical Manifestations and Diagnostic Studies
Inflammatory Response
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...
Bacterial Meningitis II: Pathophysiology