Intestinal Cytokine mRNA Expression in Canine Inflammatory Bowel Disease: A Meta-Analysis with Critical Appraisal

摘要

Dataimplicatingmucosalcytokinesinthepathogenesisofcanineinflammatoryboweldisease(IBD)arelimited.TheaimsofthepresentstudyweretoreportnewfindingsofintestinalcytokineexpressionindogswithIBDandtocomparethesedatawithpreviousstudiesthroughmeta-analysis.CytokinemRNAabundanceinintestinalbiopsiescollectedprospectivelywasevaluatedbyusingasemiquantitativeRT-PCRtechnique.Formeta-analysis,anelectronicdatabasesearchrevealed3clinicaltrials,allofwhichwerenonrandomized(typeIII)caseseries.ProspectiveanalysisshowedthattheintestinesofhealthydogsandthosewithIBDexpressnumerouscytokinesandthataproinflammatoryexpressionprofileisnotafeatureofsmallorlarge-intestinalIBD.Themeta-analysisdataincluded158dogscharacterizedashealthy(n=45),diarrheicnonIBDdogs(n=6),nonresponders(n=2),small-intestinalIBD(n=41),colonicIBD(n=25),andchronicenteropathy(n=39).Germanshepherddogswereoverrepresentedin3ofthe4studies.HealthydogsshowedmRNAexpressionformostcytokinesincludingIL2,IL4,IL5,IL10,IL12,IFN#59138;,TNF#945;,andTGF#59137;.OnlyIL12mRNAexpressionwasincreasedconsistentlyinsmall-intestinalIBD,whereasIBDcolitislackedconsistentpatternsofexpression.Insummary,dogswithIBDfailtoexpressapredominantTh1-orTh2cytokinebiasininflamedmucosa.HeterogeneityofresultsamongthesestudiesmightbeexplainedbynumerousfactorsincludingthemethodofmRNAquantification,stageofdisease,anddemographicdifferencesinstudypopulations.