Serum soluble TNF receptor I and II levels correlate with disease activity in IBD patients.
BACKGROUND
Tumor necrosis factor alpha (TNFalpha) is a proinflammatory cytokine and an important mediator in the pathophysiology of inflammatory bowel disease (IBD). The effects of TNFalpha are mediated by 2 specific receptors, a 55-kDa protein (TNF-RI) and a 75-kDa receptor (TNF-RII), which are usually bound to the cell surface. Soluble TNF receptors I and II (sTNF-RI + II) are released by proteolytic cleavage of the extracellular domains of these receptors. Soluble TNF-Rs act as TNF antagonists and can inhibit TNFalpha-mediated proinflammatory effects.


METHODS
Levels of sTNF-RI + II were measured using commercially available enzyme-linked immunosorbent assays (ELISAs). Serum levels of sTNF-RI + II of 76 healthy volunteers were compared to serum levels of 373 clinically well-characterized patients with Crohn's disease (CD) and 118 patients with ulcerative colitis (UC) with different disease activity from the German IBD competence network serum bank. CD patient subgroups were defined according to the Vienna Classification.


RESULTS
The serum levels of sTNF-RI were significantly increased in all groups (active, chronic active, and remission) of CD and UC patients compared to healthy controls. sTNF-RII levels were significantly higher in active CD patients compared to UC patients with no overlap of the 95% confidence interval. Significantly higher values of sTNF-RII compared to controls were also observed in CD patients and UC patients in remission. There was no statistically significant difference in sTNF-RI or sTNF-RII levels when patient subgroups were analyzed according to disease behavior or disease localization.


CONCLUSIONS
sTNF-RI is upregulated in the serum of IBD patients compared to healthy controls and could be used as a marker for disease activity. sTNF-RII levels are significantly more elevated in serum of active CD patients as compared to UC and could be used as an additional parameter to discriminate both diseases.
Spoettl
Tanja
T
Department of Internal Medicine I, University of Regensburg, Germany.
Hausmann
Martin
M
Klebl
Frank
F
Dirmeier
Andrea
A
Klump
Bodo
B
Hoffmann
Joerg
J
Herfarth
Hans
H
Timmer
Antje
A
Rogler
Gerhard
G
D000328:Adult; D015415:Biomarkers / Q000097:blood; D002908:Chronic Disease; D016001:Confidence Intervals; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000097:blood*; D008297:Male; D011379:Prognosis; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000097:blood*; D047889:Receptors, Tumor Necrosis Factor, Type II / Q000097:blood*; D012720:Severity of Illness Index
D015415:Biomarkers; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II