The predictive value of drug resistance gene detection for the prognosis of patients with pulmonary tuberculosis / 中华传染病杂志

ABSTRACT

Objective To identify drug resistance status of Mycobacterium tuberculosis (MTB) strains by the GenoType MTBDRplus line-probe assay (LPA),compare its performance with traditional drug susceptibility testing (DST),and to assess its predictive value for the prognosis of patients with drug resistance tuberculosis.Methods Pulmonary tuberculosis patients who visited Zhuji People's Hospital,Zhejiang Province during February 2011 and January 2012 with a positive result of sputum smear at baseline were all recruited.A total of 275 culture positive specimens were collected,then isolated and cultured for Mycobacterium tuberculosis in the laboratory.DST were performed,meanwhile,GenoType MTBDRplus were also applied to detect resistance to isoniazid (INH) and rifampin (RMP).All the tuberculosis patients who were recruited were followed,including sputum culture and chest radiography.Results There were 192 strains showing drug resistance both by DST and MTBDRplus LPA.Fourteen multidrug resistant (MDR),21 INH mono-resistant and 2 RMP mono-resistant strains were detected by DST.As for GenoType MTBDRplus LPA,MDR,INH mono-resistant and RMP mono-resistant strains were 14,18 and 2,respectively.Taken DST as the gold standard,LPA was more accurate in the detection of resistance to RMP,while it failed to detect 23.8％ (5/21) of the INH-resistant strains.We analyzed the prognosis of patients with drug resistance by GenoType MTBDRplus LPA,the rates of treatment success were 84 ％ (110/131),9/15,3/11 in patients infected with susceptible,INH mono-resistant and MDR strains,respectively.For the 2 cases of RMP mono-resistanee,one was cured and the other failed.The predictive value of molecular drug resistance test for treatment failure in INH mono-resistant patients was 40.0 ％,while that was 83.5 ％ for treatment success in INH susceptible patients.The predictive value for treatment failure in RMP mono-resistant patients was 50.0％,while that was 81.5％ for treatment success in RMP susceptible patients.The predictive value for treatment failure in MDR patients was 72.7％,while that was 81.1％ for treatment success in patients without MDR.Conclusion The GenoType MTBDRplus LPA assay is a rapid and reliable diagnostic test for resistance of MTB,which can be used to predict the prognosis of drug resistant tuberculosis in the clinical practice.