Interleukin-6 serum levels correlate with footpad swelling in adjuvant-induced arthritic Lewis rats treated with cyclosporin A or indomethacin.
To investigate the role of interleukin 6 (IL-6) in adjuvant-induced arthritis, serum from adjuvant-immunized Lewis rats treated with cyclosporin, indomethacin, or saline was evaluated for IL-6 activity. Inflammation was quantitated by measuring paw volume. We found that an increase in serum IL-6 activity parallels the kinetics of paw edema development in adjuvant-immunized rats. Daily treatment with 5 mg cyclosporin A/kg prevented the increase in paw volume and held serum IL-6 activity to levels observed in untreated (normal) rats. Daily treatment with 1 mg indomethacin/kg resulted in a 50% reduction in serum IL-6 levels and a significant decrease (approximately 50%) in paw volume on Day 17 compared to saline-treated rats. Linear regression analysis confirmed the positive correlation between mean paw volume and mean serum IL-6 activity (R2 = 0.783, P less than 0.01 on Day 17) in normal, arthritic, and cyclosporin A- or indomethacin-treated groups. These results are consistent with a role for IL-6 in the pathology of arthritis and suggest that serum IL-6 activity may be a useful parameter for monitoring disease activity.
Leisten
J C
JC
Immunetech Pharmaceuticals, San Diego, California 92121.
Gaarde
W A
WA
Scholz
W
W
D000818:Animals; D001168:Arthritis / Q000097:blood*; D001169:Arthritis, Experimental / Q000097:blood* / Q000188:drug therapy; D003524:Cyclosporins / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004487:Edema; D005528:Foot; D007213:Indomethacin / Q000627:therapeutic use*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D009169:Mycobacterium tuberculosis; D051381:Rats; D011917:Rats, Inbred Lew
D003524:Cyclosporins; D015850:Interleukin-6; D007213:Indomethacin