Open AccessRegulation of interleukin‐18 binding protein production by blood and synovial cells from patients with rheumatoid arthritis
Author(s) -
Kawashima Masanori,
Novick Daniela,
Rubinstein Menachem,
Miossec Pierre
Publication year - 2004
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.20320
Subject(s) - peripheral blood mononuclear cell , synovial fluid , rheumatoid arthritis , messenger rna , synovial membrane , medicine , endocrinology , immunology , stimulation , whole blood , chemistry , microbiology and biotechnology , biology , in vitro , gene , pathology , biochemistry , osteoarthritis , alternative medicine
Objective To study the regulation of interleukin‐18 binding protein (IL‐18BP) production by rheumatoid arthritis (RA) or control peripheral blood mononuclear cells (PBMCs) and by RA synovial tissue cells, and to compare the levels of IL‐18BP messenger RNA (mRNA) expression in whole blood from RA patients and controls. Methods Unstimulated or phytohemagglutinin and phorbol myristate acetate (PHA/PMA)–stimulated PBMCs from 10 RA patients and 12 healthy controls and unstimulated or PHA/PMA‐stimulated synovial tissue cells from 8 RA patients were cultured with or without IL‐12 (1 ng/ml) and IL‐18 (5 ng/ml) alone or in combination. IL‐18BP and interferon‐γ (IFNγ) levels in supernatants were measured by enzyme‐linked immunosorbent assay. Levels of IL‐18BP and IFNγ mRNA expression in whole blood samples from 22 RA patients and 12 healthy controls were determined by quantitative reverse transcriptase–polymerase chain reaction. Results IL‐12 decreased the basal levels of IL‐18BP production by freshly isolated RA or control PBMCs, but increased those of synovial cells or PHA/PMA‐stimulated PBMCs. IL‐18 alone had no direct effect on IL‐18BP production by PBMCs or RA synovial cells, with or without stimulation. Unstimulated whole blood samples from RA patients showed lower levels of IL‐18BP mRNA expression than those from healthy controls. Conclusion The production of IL‐18BP in response to IL‐12 and IL‐18 was regulated differently in blood and synovial cells. The difference appears to be related to the level of cell activation.