简介：AIM:ToinvestigateapathophysiologicalroleofcathepsinW(CatW),aputativethiol-dependentcysteineprotease,whichisspecificallyexpressedincytotoxiclymphocytes,indifferenttypesofchronicinflammationofthegastricmucosa.METHODS:GastricandduodenalbiopsiesofpatientswithHelicobacterpylori(Hpylori)-associatedactivegastritis(Hp,n=19),chemicallyinducedreactivegastritis(CG,n=17),autoimmuneatrophicgastritis(AIG,n=20),lymphocyticcorpusgastritis(LG,n=29),celiacdisease(CD,n=10),andcorrespondingcontrols(n=24)wereanalyzedbyimmunohistochemistryfortheexpressionofCatWandCD45.Furthermore,immunohistochemicaldoublestainingwithanti-CD3andanti-cathepsinwasperformedforthesamplesofAIG.RESULTS:MedianvaluesofCatW-expressingcellsamongCD45-positiveimmunecellswerebetween2%and6%fornormalgastricmucosa,CG,andLG,whereasthecorrespondingvaluewassignificantlyincreasedforAIG(24.7%,P＜0.001)andsignificantlydecreasedforHP(0.7%,P＜0.05).Doublestainingwithanti-CD3andantiCatWantibodiesrevealedthat＞90%ofCatW-expressingcellsingastricmucosaofAIGwereTcells.DuodenalmucosahadsignificantlymoreCatW/CD45-positivecellsthannormalgastricmucosa(median:17.8%vs2%,P＜0.01).ThecorrespondingproportionofCatW/CD45-positivecellswasdecreasedinCDcomparedtoduodenalmucosa(median:2.1%vs17.8%,P＜0.05).CONCLUSION:TheoppositefindingsregardingthepresenceofCatW-positivecellsinAIG(increase)andCD(decrease)reflectsthedifferentcellularcompositionofimmunecellsinvolvedinthepathogenesisofthesediseases.