Diagnostic Performance of a Novel mRNA Release Assay for Infection.

One-fourth of the world's population has been infected with (). Although interferon-gamma release assays (IGRAs) have been shown to be valid methods for identifying infection and auxiliary methods for diagnosis of active tuberculosis (TB), lower sensitivity and higher indeterminate rate were often detected among immunosuppressed patients. IP-10 was an alternative biomarker due to the higher expression level after antigen stimulation, but whether mRNA (the gene that transcribes for the IP-10 protein) can be used as a target for infection diagnosis was limited. Therefore, we aimed to evaluate the performance of a novel -specific mRNA release assay in diagnosis of infection. Suspected TB patients and healthy controls were prospectively recruited between March 2018 and November 2019 from three hospitals in China. mRNA release assay and traditional interferon-gamma release assay (T-SPOT.TB) were simultaneously performed on peripheral blood. Of the 1,479 participants enrolled in the study, 352 patients with definite TB and 153 healthy controls were analyzed. mRNA release assay provided a sensitivity of 93.9% (95% CI = 90.8-96.2%) and a specificity of 98.0% (95% CI = 94.3-99.6%) in the diagnosis of infection, respectively, while T-SPOT.TB gave a sensitivity of 94.5% (95% CI = 91.5-96.6%) and a specificity of 100% (95% CI = 97.6-100.0%) in the diagnosis of infection, respectively. The diagnostic performance of mRNA release assay was consistent with T-SPOT.TB, with a total coincidence rate of 95.0% (95% CI = 93.0-96.9%) and a Cohen's kappa value of 0.89 (0.84-0.93, < 0.001). However, among TB patients with HIV co-infection ( = 14), mRNA release assay presented significantly higher positive rate [92.9% (66.1-99.8%) . 61.5% (31.6-86.1%), = 0.029] than those of T-SPOT.TB. These results suggested that -specific mRNA was a novel and useful target in the diagnosis of infection.