Diagnostic value of cross-primer isothermal amplification technology in tuberculosis and its related influencing factors / 中国热带医学

ABSTRACT

@#Abstract： Objective　To analyze the value and influencing factors of cross-primer isothermal amplification technology(CPA) in clinical screening and diagnosis of tuberculosis (TB). Methods　We collected 543 inpatients in the Second Affiliated Hospital of Hainan Medical College from January 1, 2018 to December 31, 2021, including 179 patients with tuberculosis, 187 patients with pneumonia and 177 patients with other diseases. The patients' sputum, alveolar lavage fluid, pleural effusion and midstream urine were detected by CPA, smear microscopy, culture method and gene detection. The value of CPA detection in the diagnosis of tuberculosis and its influencing factors were evaluated. Statistical analysis was performed using SPSS 26.0. Results　The total positive rate of CPA was 14.4% (78/543), and the positive rate of sputum samples accounted for 29.1% (39/134). Among the 78 cases of CPA positive patients, the tuberculosis group accounted for 69.2% (54/78), followed by pneumonia group 21.8% (17/78), and other diseases group accounted for 9.0% (7/78). Taking CPA test as the reference method, the "sensitivity" of smear microscopy was lower than that of genetic testing and culture, while the "specificity" was higher than that of culture and gene testing, and the "missed diagnosis rate" of smear microscopy was higher than that of genetic testing and culture. CPA test positive was related to gender, ESR and pneumonia. There is a good agreement between CPA test and culture method and gene test (Kappa>0.9), and a moderate agreement between CPA test and smear microscopy (Kappa=0.616). Conclusions　Sputum specimen is the best choice for CPA detection, while the value of pleural effusion detection is relatively limited. Sputum, alveolar lavage fluid and midcourse urine can be used as clinical specimens for screening and diagnosis of "tuberculosis group and other disease group", while sputum can be used for screening and diagnosis of "tuberculosis group and pneumonia group". Gender, ESR and pneumonia are the influencing factors of CPA positive patients. Therefore, CPA testing is worthy of clinical promotion, but more clinical research data are needed.