Tohoku J. Exp. Med., 1999, 188 (1)

The Participation of IL-8 in the Synovial Lesions at an Early Stage of Rheumatoid Arthritis

YUICHI TAKAHASHI,1,2 TADASHI KASAHARA,3 TAKASHI SAWAI,4 AKIRA RIKIMARU,5 NAOFUMI MUKAIDA,6 KOUJI MATSUSHIMA7 and TAKESHI SASAKI2

1Department of Rheumatology, Tohoku Kosei-Nenkin Hospital, Sendai 983-8512, 2Department of Clinical and Laboratory Medicine, Tohoku University School of Medicine, Sendai 980-8574, 3Department of Biochemistry, Kyoritsu College of Pharmacy, 4Department of Pathology, Tohoku University School of Medicine, 5Orthropediatrics, National Naruko Hospital, Naruko 989-6801, 6Department of Pharmacology, Cancer Research Institute, Kanazawa University, Kanazawa 920-0934, and 7Department of Molecular Preventive Medicine, Graduate School of Medicine, University of Tokyo, Tokyo 113-0033

  • Synovial tissues from Rheumatoid Arthritis (RA) were divided into three groups based on their histopathological findings and compared for their expression of IL-8 and monocyte chemotactic and activating factor (MCAF) by using immunohistochemistry and in situ hybridization. The levels of IL-8 as well as those of MCAF were markedly higher in the synovial fluid from RA joints. Synovial lining cells (SLC) and macrophages had an ability to produce IL-8 at an early phase of the disease. The presence of MCAF was restricted in macrophages at this stage. On the other hand, the production of IL-8 as well as MCAF were prominent in most components of the joints such as SLC, migrated monocytes, sublining fibroblastoid cells, endothelial cells or migrated neutrophils at an active phase. The expression of IL-8 or MCAF was low in fibrotic synovitis of RA. These data indicate that IL-8 generated from SLC and macrophages may participate to the inflammatory process in the early synovitis of RA.
    Key words--- rheumatoid arthritis; interleukin-8; monocyte chemotactic and activating factor; in situ hybridization; immunohistochemistry
    © 1999 Tohoku University Medical Press

    Tohoku J. Exp. Med., 1999, 188, 75-87
    Address for reprints: Yuichi Takahashi, Department of Rheumatology, Tohoku Kosei-Nenkin Hospital, 1-12-1 Fukumuro, Miyagino-ku, Sendai 983-8512, Japan.

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