Soluble interleukin-6 receptors in inflammatory bowel disease: relation to circulating interleukin-6.
The in vivo appearance of soluble interleukin (IL)-6 receptor (sIL-6R) in serum from patients with inflammatory bowel disease was examined using an enzyme linked immunosorbent assay (ELISA). The serum sIL-6R concentrations in patients with active disease (ulcerative colitis, 148.4 (5.1); Crohn's disease, 142.3 (9.3) ng/ml; mean (SEM)) were significantly raised compared with those in patients with inactive disease (ulcerative colitis, 116.2 (7.2); Crohn's disease, 114.3 (7.1) ng/ml), some other type of colitis (104.8 (11.6) ng/ml), or in normal subjects (107.3 (2.4) ng/ml). These differences were also seen in paired samples examined during both active and inactive phases. Additionally, serum sIL-6R and IL-6 concentrations correlated significantly with C-reactive protein levels in both ulcerative colitis and Crohn's disease patients (r = 0.23 and 0.56, respectively; p < 0.05 for both). Furthermore, gel filtration analysis of serum from these patients showed two major peaks of immunoreactive IL-6-one peak corresponding to free IL-6 and another peak to sIL-6R-bound IL-6-this was further confirmed by a luminescence sandwich ELISA. These results, together with its in vitro effects, indicate that natural sIL-6R may function as a powerful enhancer of the IL-6-dependent immune processes observed in inflammatory bowel disease.
Mitsuyama
K
K
Second Department of Medicine, Kurume University School of Medicine, Fukuoka, Japan.
Toyonaga
A
A
Sasaki
E
E
Ishida
O
O
Ikeda
H
H
Tsuruta
O
O
Harada
K
K
Tateishi
H
H
Nishiyama
T
T
Tanikawa
K
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D002850:Chromatography, Gel; D003092:Colitis / Q000276:immunology; D003093:Colitis, Ulcerative / Q000097:blood* / Q000276:immunology; D003424:Crohn Disease / Q000097:blood* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018123:Receptors, Interleukin / Q000032:analysis*; D019947:Receptors, Interleukin-6; D012995:Solubility
D015850:Interleukin-6; D018123:Receptors, Interleukin; D019947:Receptors, Interleukin-6