ObjectivesTodetectionofchlamydiapneumoniae(Cpn)DNAinthecirculatingmononuclearcellfractionsofcoronaryheartdiseaseandtoinvestigatetheassociationbetweeninfectionwithchlamydiapneumoniaeandcoronaryheartdisease(CHD)andprospectivelywhetherblood-basednestedpolymerasechainreaction(nPCR)isusefulinidentifyingCpninfection.MethodsTheperipheralbloodmononuclearcell(PBMC)CpnDNAwasexaminedusingnPCRtechniqueandconfirmedbyelectrophoresisin150patientswithCHD.Select55patientswithclinicalsuspectedCHDbutangiographyresultarenormalascontrolgroup(CG).Thenweconductedaprospective,randomized,double-blind,placebo-controlledstudyof6monthsofazithromycinandplacebotreatmentinCHDgroup.PatientswithCpnDNApositivewerethenrandomizedtoreceiveazithromycinorplacebo.Aftertreatmentbloodsamplewerecollectedforrepeatedmeasurement.ResultsChlamydiapneumoniaeDNAwasdetectedin49(32.7%)of150personswithCHDandin1(1.8%)of55personswithcontrolgroup,oddsratio26.2,95%confidenceinterva13.52-194.98.ThepositivityratesofnPCRinCHDgroupswerehigherthanthoseincontrolgroup.16cases(29.1%)inlatentcoronaryheartdiseases(LCHD)group,19cases(39.6%)inunstableangina(UAP)group,and14cases(29.9%)inacutemyocardialinfarction(AMI)groupwereCpnpositivebynPCR.TherewerenosignificantdifferenceamonginAMIUAPandLCHDgroup.ThereweresignificiantdifferenceinCpnDNAnegativeratesaftertheazithromycinandtheplacebotreatment.ConclusionsChlamydiapneumoniaeispresentinPBMCofasignificantproportionofpersonswithCHD.Thepotentialroleofchlamydiapneumoniaeincoronaryatherosclerosismaythereforebemorerelatedtoaccelerationofdiseaseorsystemiceffectsbypersistentinfectionthantosuddeninitiationofprogressivecoronaryarterydiseasebyacuteinfection.ThedetectionofCpnDNAinPBMCwithnPCRmaybeofgreatvalueforidentifyingCpncarriersandfo
