The value of linear probe assay(HAIN) for the diagnosis of M. tuberculosis and the detection of rifampin and isoniazid resistance in spinal tuberculosis

English Keywords:Mycobacterium tuberculosis  Spine  Drug sensitivity testing  Drug resistance  Linear probe assay

English Abstract:

  【Abstract】 Objectives: To evaluate the value of Hain GenoType MTBDR plus(HAIN) for the diagnosis of M. tuberculosis and the detection of rifampin(RIF) and isoniazid(INH) resistance in spinal tuberculosis. Methods: 235 hospitalized patients with spinal infection were enrolled, including 132 males and 103 females, aged from 1 to 84 years with an average age of 42.8±18.1 years, selected from the Orthopedic Department of Beijing Chest Hospital affiliated to Capital Medical University from June 2015 to December 2016. According to the results of interferon gamma release test, common bacterial culture and fungal culture,all patients were divided into two groups. One was tuberculous group including 219 cases with spinal tuberculosis and the other group was non-tuberculous group including 16 cases with spinal infection with non-tuberculous bacterium or fungus. All patients′ specimens were collected using needle puncture or surgery and sent for the detection of MTB using HAIN and co-culture within 2 hours. The co-culture was to carry out BACTEC MGIT 960 system culture and modified Roche medium culture at the same time. As long as one method of culture was to be positive, co-culture was to be identified as positive. Then the culture positive strains were to be performed for drug sensitivity test(DST). The sensitivity and specificity of HAIN for detection of MTB was to be compared with co-culture. The sensitivity and specificity of detection of RIF resistance and INH resistance and multiple drug-resistance(MDR, both RIF and INH resistance) were to be compared between HAIN and DST. The consistency of HAIN test results was evaluated according to the results of DST. Results: The positive detection of MTB was found in 120 cases and 104 cases using HAIN and co-culture, respectively. The sensitivity of detection of MTB was 54.8% and 47.5% without a significant difference(χ2=2.339，P=0.126), respectively. The specificity using HAIN and co-culture were both 100%. The positive rate of detection of MTB was 63.5% and 47.0%, respectively, in culture positive specimens and culture negative specimens using HAIN, with a significant difference (χ2=6.006, P<0.05). Compared with the DST, the sensitivity and specificity of detection of RIF resistance, INH resistance and MDR was 87.5% and 94.8%(Kappa=0.743, P<0.001), 66.7% and 86.0%(Kappa=0.472, P<0.001), 85.7% and 93.2%(Kappa=0.664, P<0.001), respectively, using HAIN. Conclusions: The HAIN, which is an accurate tool for the detection of MTB and its RIF resistance and INH resistance, has a good application prospect in spinal tuberculosis．