Pleasecitethisarticleinpressas:RoloR,etal.Crohn’sdiseaseandintestinaltuberculosis:Aclinicalchallenge.RevPort Pneumol.2012.doi:10.1016/j.rppneu.2012.02.006
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LETTER
TO
THE
EDITOR
Crohn’s
disease
and
intestinal
tuberculosis:
A
clinical
challenge
Doenc
¸a
de
Crohn
e
tuberculose
intestinal:
um
desafio
clínico
DearEditor,
The distinction between Crohn’s disease and intestinal tuberculosis is a diagnostic challenge as they present similar clinical, radiological, endoscopic and histological features.1---3Adefinitivediagnosisinthesecasesisextremely
important, to avoid the toxicity of unnecessary anti-tuberculous therapy in patients with Crohn’sdisease and potentially fatalimmunosuppressivetreatment inpatients withintestinalTB.Histologicalexamination,complemented by other diagnostic tests, including tests of nucleic acid amplification, is pivotal in the differential diagnosis.1,2
Other methods like immunohistochemistry are emerging withpromisingresultsin determiningearlydifferentiation ofbothillnesses.3
Patients with Crohn’s disease eligible for TNF antago-nist(infliximaboradalimumab)orotherimmunosuppressive treatmentarefrequentlysenttoourPneumologicDiagnosis CenterforTBscreening,asrecommendedbyTBNET consen-susstatement.4Thescreeningprogramincludesasymptom
questionnaire,atuberculinskintest(PPDRT23),interferon gamma release assay (IGRA) and chest radiography. The needforasoliddiagnosis,beforequalifyingpatientsforTNF antagonists,ledustoincludein thescreeningprogramme arevisionofbiopsyspecimenswithacidfastbacillismear, nucleicacidamplificationtest andculturalexaminationin recentbiopsiesor,atleast,toensurethatthesehad previ-ouslybeenperformed.
Wethereforedecidedtocarryoutaretrospectivecohort from2008toanalyzehowthismeasurehashelpedtoexclude intestinaltuberculosisandsafelyqualifypatients for anti-TNFtreatment.Weincluded47patientswiththediagnosis of Crohn’sdisease;51% femaleand meanage of38 years old.Revisionofendoscopicbiopsieswaspossiblein25(53%) individuals.Two(8%)casesofintestinalTBwerediagnosed by this process,one withpositive smear, other withboth positive nucleic acid amplification test and culture. Both startedanti-TBtreatment.Patientseligiblefor immunosup-pressivetherapyhadthreedifferentoutcomes:21patients hadTBlatentinfectionandweresubmittedto9-month iso-niazidregimen;in2patientsCrohn’sdiseasewasreplaced
by intestinal TB as a correct diagnosis; 24 patients had negativeTB screening andqualified tofor anti-TNF treat-ment.Twenty-sevenpatientsstartedanti-TNFtherapy(the 24patientsthathadnegativeTBscreening and3patients underTB latent infectiontreatment) andnone developed activeTB.Insummary,thisprocedureallowedustodiagnose 2casesofintestinaltuberculosismisinterpretedasCrohn’s diseaseand to safely initiate TNF antagonist without any caseofactiveTBfollowingthattreatment.
In conclusion, investigation of patients withsuspected Crohn’s disease should always include differential diag-nosis with intestinal tuberculosis. Acid fast bacilli smear, nucleicacidamplificationtestsandculturearewarrantedin pathologicalexaminationofendoscopicbiopsies.These pro-ceduresarecurrently routinepracticein ourPneumologic DiagnosisCenter,wheninvestigatingpatientswithsuspected Crohn’sdisease.Alternativeroutes ofdifferentiating both illnesseshavebeenmentionedbyothers5andmaybeadded
tothescreeningprograminthefuture.
References
1. Kim BJ, ChoiYS, Jang BI, Park YS, Kim WH, Kim YS, et al. Prospective evaluation of the clinical utility of interferon-␥
assay in the differential diagnosis of intestinal tuberculosis and Crohn’s disease. Inflamm Bowel Dis. 2011;17:1308---13, doi:10.1002/ibd.21490.
2.LødrupA,EiholmS,MeyerC,BremholmL.Intestinaltuberculosis asadifferentialdiagnosisofinflammatoryboweldisease.Ugeskr Laeger.2010;172:2902---3.
3.InceAT,Günes¸P,Senates¸E,SezikliM,Tiftikc¸iA,Ovünc¸O.Can animmunohistochemistrymethoddifferentiateintestinal tuber-culosis from Crohn’sdisease inbiopsyspecimens?Dig DisSci. 2011;56:1165---70.
4.SolovicI,SesterM,Gomez-ReinoJJ,RiederHL,EhlersS,Milburn HJ,etal.Theriskoftuberculosisrelatedtotumornecrosisfactor antagonisttherapies:aTBNETconsensusstatement.EurRespir J.2010;36:1185---206,doi:10.1183/09031936.00028510. 5. Jolobe OM.Interferon-␥mayimprove differentiationbetween
intestinaltuberculosisandCrohn’sdisease.AmJGastroenterol. 2010;105:2114,doi:10.1038/ajg.2010.206.
Pleasecitethisarticleinpressas:RoloR,etal.Crohn’sdiseaseandintestinaltuberculosis:Aclinicalchallenge.RevPort Pneumol.2012.doi:10.1016/j.rppneu.2012.02.006
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2 LETTERTOTHEEDITOR
R.Roloa,b,∗,S.Campainhaa,d, R.Duartea,b,c,e
aCentrodeDiagnósticoPneumológicodeVilaNovade
Gaia,VilaNovadeGaia,Portugal
bServic¸odePneumologia,HospitaldeBraga,Braga,
Portugal
cCentrodeReferênciaRegionaldeTBMRdoNorte,
Portugal
dServic¸odePneumologia,CentroHospitalardeVilaNova
deGaia/Espinho,VilaNovadeGaia,Portugal
eDepartamentodeEpidemiologia,FaculdadedeMedicina,
UniversidadedoPorto,Porto,Portugal
