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Immune complex formation between IgM rheumatoid factor and IgG generated by hyaluronic acid
P Faaber1, L A van den Bersselaar, L B van de Putte
1Department of Rheumatology, St. Radboud Hospital, University of Nijmegen, The Netherlands.
Arthritis and Rheumatism
|December 1, 1989
Summary
Hyaluronic acid (HA) in rheumatoid arthritis (RA) joints promotes the formation of immune complexes. This explains why immune cells in RA synovial fluid, unlike those in blood, contain immunoglobulin inclusions, driving joint inflammation.
Area of Science:
- Rheumatology
- Immunology
- Biochemistry
Background:
- Granulocytes in rheumatoid arthritis (RA) synovial fluid often contain immunoglobulin inclusions, unlike those in peripheral blood.
- The presence of these inclusions suggests a localized immune process within the joint.
Purpose of the Study:
- To investigate the role of hyaluronic acid (HA) in the formation of immunoglobulin inclusions in RA granulocytes.
- To elucidate the mechanism by which HA influences immune complex formation in the RA joint.
Main Methods:
- Utilized the indirect granulocyte phagocytosis test (IGPT) to assess immune complex uptake.
- Tested the effect of varying concentrations of HA on RA sera and purified IgM-rheumatoid factor (RF).
Main Results:
- Hyaluronic acid (HA) significantly increased the avidity of rheumatoid factor (RF), promoting IgG-IgM-RF complex formation.
- HA addition to RA sera led to a dose-dependent increase in immune complex uptake by granulocytes via IGPT.
- Supplementation of normal serum with IgM-RF in the presence of HA also resulted in a dose-dependent positive IGPT.
Conclusions:
- Hyaluronic acid (HA), a component of synovial fluid, facilitates the formation of immune complexes in the rheumatoid arthritis joint.
- This HA-mediated immune complex formation likely contributes to the inflammatory reactions observed in RA joints.