Serum analysis of tryptophan catabolism pathway: correlation with Crohn's disease activity.
Inflamm Bowel Dis
; 18(7): 1214-20, 2012 Jul.
Article
em En
| MEDLINE
| ID: mdl-21823214
ABSTRACT
BACKGROUND:
Indoleamine 2,3 dioxygenase-1 (IDO1) is a tryptophan catabolizing enzyme with immunotolerance-promoting functions. We sought to determine if increased gut expression of IDO1 in Crohn's disease (CD) would result in detectable changes in serum levels of tryptophan and the initial IDO1 pathway catabolite, kynurenine.METHODS:
Individuals were prospectively enrolled through the Washington University Digestive Diseases Research Center. The Montreal Classification was used for disease phenotyping. Disease severity was categorized by the Physician's Global Assessment. Serum tryptophan and kynurenine were measured by high-pressure liquid chromatography. IDO1 immunohistochemical staining was performed on formalin-fixed tissue blocks.RESULTS:
In all, 25 CD patients and 11 controls were enrolled. Eight CD patients had serum collected at two different timepoints and levels of disease activity compared. Strong IDO1 expression exists in both the lamina propria and epithelium during active CD compared to controls. Suppressed serum tryptophan levels and an elevated kynurenine/tryptophan (K/T) ratio were found in individuals with active CD as compared to those in remission or the control population. K/T ratios correlated positively with disease activity as well as with C-reactive protein and erythrocyte sedimentation rate. In the subgroup of CD patients with two serum measurements, tryptophan levels were elevated while kynurenine levels and the K/T ratio lowered as the disease activity lessened.CONCLUSIONS:
IDO1 expression in CD is associated with lower serum tryptophan and an elevated K/T ratio. These levels may serve as a reasonable objective marker of gut mucosal immune activation and as a surrogate for CD activity.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Triptofano
/
Biomarcadores
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Doença de Crohn
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Indolamina-Pirrol 2,3,-Dioxigenase
/
Cinurenina
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
/
Prognostic_studies
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Risk_factors_studies
Limite:
Adult
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Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Inflamm Bowel Dis
Assunto da revista:
GASTROENTEROLOGIA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos