The expression of IL-12 p40 and its homologue, Epstein-Barr virus-induced gene 3, in inflammatory bowel disease.
BACKGROUND
It has recently been suggested that Crohn's Disease (CD) is associated with an exaggerated T helper 1 cytokine response as manifest by increased production of interleukin-12 (IL-12) and interferon-gamma (IFN-gamma). Epstein-Barr virus-induced gene 3 (EBI3) encodes a 34-kDa glycoprotein that is 27% identical to the p40 unit of IL-12 and has recently been reported to be up-regulated in ulcerative colitis (UC).


OBJECTIVE
To determine whether mucosal expression of IL-12 p40 or EBI3 correlates with inflammatory bowel disease (IBD).


METHODS
mRNA expression in colonic mucosa from patients with UC, Crohn's disease (CD) and non-IBD controls was measured by reverse-transcribed real-time polymerase chain reaction (PCR).


RESULTS
EBI3 was significantly increased in both involved and uninvolved colonic mucosa in patients with UC. Although IL-12 p40 was increased in some patients with CD relative to non-IBD controls, the increase was not statistically significant. However, 5-aminosalicylic acid (5-ASA) use was significantly correlated with reduced IL-12 p40 levels in the patients with CD, but not in UC cases. A similar reduction was not seen in 5-ASA-treated UC patients.


CONCLUSIONS
IL-12 p40 expression in CD is heterogeneous. In contrast, expression of the IL-12 p40 homologue, EBI3, is up-regulated in nearly all UC cases and in a subset of CD.
Omata
F
F
Gastroenterology Division, Tokai University School of Medicine, Kanagawa, Japan.
Birkenbach
M
M
Matsuzaki
S
S
Christ
A D
AD
Blumberg
R S
RS
D000328:Adult; D016022:Case-Control Studies; D003093:Colitis, Ulcerative / Q000378:metabolism; D003424:Crohn Disease / Q000378:metabolism; D017931:DNA Primers; D015342:DNA Probes; D018076:DNA, Complementary / Q000032:analysis; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000235:genetics; D005260:Female; D006023:Glycoproteins / Q000032:analysis* / Q000235:genetics; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000235:genetics / Q000378:metabolism*; D018664:Interleukin-12 / Q000032:analysis* / Q000235:genetics; D007378:Interleukins; D008297:Male; D008875:Middle Aged; D015778:Minor Histocompatibility Antigens; D019255:NADPH Oxidases; D016133:Polymerase Chain Reaction / Q000379:methods; D011506:Proteins; D018121:Receptors, Cytokine
D017931:DNA Primers; D015342:DNA Probes; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C097732:EBI3 protein, human; D006023:Glycoproteins; D007378:Interleukins; D015778:Minor Histocompatibility Antigens; D011506:Proteins; D018121:Receptors, Cytokine; D018664:Interleukin-12; D019255:NADPH Oxidases; C113333:NCF4 protein, human