The Application Of GeneXpert MTB/RIF Technique In Diagnosis Of Lymph Node Tuberculosis

Objectives:Bacteriological culture,imaging,and routine pathology are currently routine diagnostic tools for lymph node tuberculosis.However,they are not ideal in terms of diagnosis,mainly in terms of sensitivity and specificity.The recent development of molecular biology detection methods has the advantages of accuracy and speed.Therefore,we conducted a comparative study of the new GeneXpert MTB/RIF technique and the commonly used diagnostic methods for lymph node tuberculosis.Methods:We used the resection and needle biopsy methods to collect specimens of superficial lymph node tuberculosis and other superficial lymph node diseases from December 2016 to October 2017.The collected specimen is divided into two parts..One group was used for GeneXpert MTB/RIF,One group was used for BACTEC MGIT960 culture,and Roche culture diagnosis.The other group was used for pathologic diagnosis,Mycobacterium tuberculosis Isoniazid and Rifampicin Resistance mutation Test,and PCR diagnosis of tissue specimens.Results:In patients with clinically superficial lymph node tuberculosis,65 cases(92.9%)were positive for MTBC by GeneXpert MTB/RIF,22 cases(31.4%)were positive for BACTEC MGIT960,and 12 cases(17.1%)were positive for Roche culture.Histopathological diagnosis was consistent with lymph nodes.Thirty-four patients(48.6%)were tuberculosis,53(75.7%)were positive for PCR,and the sensitivity of GeneXpert MTB/RIF was 92.9%and 100%for the diagnosis of superficial lymph node tuberculosis.It is the current diagnostic method with the highest sensitivity and specificity in the diagnosis of superficial lymph node tuberculosis.In the combined diagnosis of the two methods,the combined sensitivity of GeneXpert MTB/RIF+ pathology is the highest.In the combined diagnosis of the three methods,the combination of GeneXpert MTB/RIF+ Roche culture and MGIT960 culture + pathology has the highest sensitivity and increased sensitivity.The joint diagnosis of the GeneXpert MTB/RIF method can increase the sensitivity of the two combined diagnostic methods.There was no statistically significant difference in the use of the GeneXpert MTB/RIF method in the initial and retreatment patients but there was a statistically significant difference in the culture positive rate.The longer the patient's oral anti-tuberculosis drug is treated,the lower the positive rate of the GeneXpert MTB/RIF test.GeneXpert MTB/RIF is more sensitive than solid tissue-based specimens in pus-based specimens.Patients with pulmonary tuberculosis using the GeneXpert MTB/RIF method were more sensitive than those without tuberculosis.There was no statistically significant difference in the sensitivity of the GeneXpert MTB/RIF assay for obtaining specimens by both needle biopsy and excisional biopsy methods.Conclusions:GeneXpert MTB/RIF is the diagnostic method with the highest sensitivity and specificity in all methods of lymph node tuberculosis diagnosis.The advantages of GeneXpert MTB/RIF technology:Accurate,rapid,and small sample detection.There was no statistical difference in the use of the GeneXpert MTB/RIF method in primary and re-treatment patients but there was a statistical difference in culture positive rates.GeneXpert MTB/RIF technology has obvious advantages and can be widely used in the diagnosis of lymph node tuberculosis.