51. Interleukin-12 is expressed by infiltrating macrophages and synovial lining cells in rheumatoid arthritis and osteoarthritis.
- Author
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Sakkas LI, Johanson NA, Scanzello CR, and Platsoucas CD
- Subjects
- Adult, Aged, Female, Humans, Immunohistochemistry, Interleukin-12 genetics, Male, Middle Aged, Synovial Membrane cytology, Arthritis, Rheumatoid immunology, Interleukin-12 biosynthesis, Macrophages metabolism, Osteoarthritis immunology, Synovial Membrane metabolism
- Abstract
TH1 cytokines have recently been detected in rheumatoid arthritis (RA) and osteoarthritis (OA). For this reason we studied the TH-1-promoting cytokine IL-12 in synovial membranes from patients with RA and OA. IL-12 transcripts and protein were analyzed by reverse transcriptase-polymerase chain reaction (PCR) and immunohistochemistry, respectively. In addition, IL-12 transcripts were quantitated by competitive PCR. IL-12 transcripts (p40) were detected in 8 of 13 patients with RA and in 10 of 18 patients with OA. Their levels did not differ significantly between RA and OA. IL-12 heterodimer protein was detected by immunostaining using an anti-IL-12p70 mAb. Double labeling with anti-IL-12p70 and anti-CD68 mAbs showed that synovial lining cells and monocytes/macrophages expressed IL-12 p70 protein. The presence of IL-12 p70 protein in the synovial membranes of patients with RA and OA suggests that IL-12 may play an important immunoregulatory role in these diseases by perpetuating inflammation., (Copyright 1998 Academic Press.)
- Published
- 1998
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