The efficiency of Xpert® MTB/RIF Assay compare with Anyplex® MTB/NTM Real time detection and Anyplex® II MTB/MDR detection base on real-time PCR for MTB, MDR-TB and NTM diagnostics, study in Maharat Nakhon Ratchasima Hospital

Abstract

Pulmonary tuberculosis (TB) is the disease which cause from Mycobacterium tuberculosis (MTB) that belonging in three types depending on the severity such as first line drug resistance TB (MDR-TB), second line drug resistance TB (XDR-TB) or Wild type TB (MTB). Difference type of TB will make patient have different severity of symptom and the successful of treatment. Thus, the medical laboratory should have the high performance system to identify the type of MTB for diagnostics pulmonary tuberculosis.

This study aims to evaluate the diagnostics performance of two Real-time PCR systems for detect MTB and MDR-TB which implement in Maharat Nakhon Ratchasima Hospital’s Medical laboratory by study in 200 cases of patient’s sputum which the doctor suspect pulmonary TB and request to identify MTB and MDR-TB by Xpert® MTB/RIF Assay, Cepheid AB, Sweden (Xpert®) We divided all sample to three groups refer to the results from Xpert®. First, the result shows MTB negative for 100 cases, second, the result shows MTB positive and Rif-R negative for 50 cases and last is the result shows MTB and Rif-R positive for 50 cases and tests all sample with Anyplex® MTB/NTM real time detection (Anyplex®) and Anyplex® II MTB/MDR detection, Seegene Inc., South Korea (Anyplex® II)

In first group when testing with Anyplex® the result shows MTB positive for 1 case from 100 cases, Mycobacteria spp. (NTM) positive for 11 cases and MTB negative for 88 cases which are 1%, 11% and 88% respectively. Second group when testing with Anyplex® II the result shows MTB positive and isoniazid resistance TB (INH-R TB) for 6 cases from 50 cases and other 44 cases are same as the result from Xpert® which are 12% and 88% respectively. The third group when testing with Xpert® the result shows MTB and Rif-R positive for 6 cases and MTB, Rif-R and INH-R (MDR-TB) positive for 44 cases which are 12% and 88% respectively.

Because of the limitation of Xpert® that can’t identify NTM and INH-R TB which makes the doctor can’t get the useful and fully information for diagnosis patients correctly. Thus the Advanced Level And Secondary Care Medical Laboratory have to provide the useful and fully data for help doctor to diagnosis TB and treat the patient with antibiotics correctly for decreasing the mortality rate and the spreading of MDR-TB to the environment.

Key words: Tuberculosis, Drug-resistance TB, Real time PCR, MTB Diagnostics