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Expression of adhesion molecules on synovial fluid and peripheral blood monocytes in patients with inflammatory joint
M Köller1, M Aringer, H Kiener
1Division of Rheumatology, Department of Internal Medicine III, University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria.
Objective:
To determine the presence of adhesion molecules on monocytes/macrophages (Mphi) from peripheral blood (PB) and synovial fluid (SF) in patients with osteoarthritis (OA) and inflammatory joint diseases (rheumatoid (RA) and reactive arthritis (ReA)) in order to improve our understanding of the possible mechanisms underlying the inflammatory process.
Methods:
Whole blood and SF cells were stained with monoclonal antibodies against CD11a (LFA-1), CD15 s (sialyl-Lewis X), CD44, CD54, VLA-4, and HLA-DR counterstained with anti-CD14 antibodies as a Mphi marker for dual fluorescence analysis by flowcytometry.
Results:
On PB-Mphi, CD15s was markedly increased in both RA as well as ReA compared with OA. Furthermore, in the PB LFA-1, CD44, and HLA-DR showed a higher surface density on Mphi in ReA than in OA. Comparison between SF and PB showed significantly higher CD44 and CD54 expression on SF-Mphi. These molecules play an important part in lymphocyte-Mphi interaction.
Conclusion:
In PB from patients with inflammatory joint diseases, Mphi are activated, allowing recruitment into the synovial compartment. These disorders, in contrast with OA seem to be "systemic" in nature. Within the SF, different adhesion molecules are expressed on CD14(+) Mphi as compared with PB.
Insights
Monocytes/macrophages (Mphi) in inflammatory joint diseases show increased adhesion molecules in peripheral blood, indicating activation and recruitment to the joint. Synovial fluid Mphi express different adhesion molecules compared to peripheral blood.
Area of Science:
- Immunology
- Rheumatology
- Cell Biology
Background:
- Osteoarthritis (OA) and inflammatory joint diseases like rheumatoid arthritis (RA) and reactive arthritis (ReA) involve complex cellular mechanisms.
- Monocytes/macrophages (Mphi) play a crucial role in joint inflammation and tissue remodeling.
Purpose of the Study:
- To investigate the expression of key adhesion molecules on Mphi from peripheral blood (PB) and synovial fluid (SF).
- To differentiate Mphi activation states in OA versus inflammatory joint diseases (RA, ReA).
- To elucidate the role of Mphi adhesion molecules in the pathogenesis of joint inflammation.
Main Methods:
- Flow cytometry was used for dual fluorescence analysis of Mphi.
- Monoclonal antibodies targeted adhesion molecules CD11a (LFA-1), CD15s (sialyl-Lewis X), CD44, CD54, VLA-4, and HLA-DR.
- Anti-CD14 antibodies identified Mphi in both PB and SF samples.
Main Results:
- CD15s expression was significantly higher on PB-Mphi in RA and ReA compared to OA.
- PB-Mphi in ReA showed increased LFA-1, CD44, and HLA-DR surface density versus OA.
- SF-Mphi exhibited significantly higher CD44 and CD54 expression than PB-Mphi.
Conclusions:
- Mphi in the peripheral blood of patients with inflammatory joint diseases are activated, facilitating their recruitment into the synovial compartment.
- Inflammatory joint diseases (RA, ReA) appear to have a systemic component, unlike OA.
- Distinct adhesion molecule profiles exist between SF-Mphi and PB-Mphi in CD14(+) cells.