Analysis of the diagnostic efficacy of the QuantiFERON-TB Gold In-Tube assay for preoperative differential diagnosis of spinal tuberculosis

Abstract

BackgroundDifferential diagnosis of spinal tuberculosis is important for the clinical management of patients, especially in populations with spinal bone destruction. There are few effective tools for preoperative differential diagnosis in these populations. The QuantiFERON-TB Gold In-Tube (QFT-GIT) test has good sensitivity and specificity for the diagnosis of tuberculosis, but its efficacy in preoperative diagnosis of spinal tuberculosis has rarely been investigated.MethodA total of 123 consecutive patients with suspected spinal tuberculosis hospitalized from March 20, 2020, to April 10, 2022, were included, and the QFT-GIT test was performed on each patient. We retrospectively collected clinical data from these patients. A receiver operating characteristic (ROC) curve was plotted with the TB Ag-Nil values. The cutoff point was calculated from the ROC curve of 61 patients in the study cohort, and the diagnostic validity of the cutoff point was verified in a new cohort of 62 patients. The correlations between TB Ag-Nil values and other clinical characteristics of the patients were analyzed.ResultsOf the 123 patients included in the study, 51 had confirmed tuberculosis, and 72 had non-tuberculosis disease (AUC=0.866, 95% CI: 0.798-0.933, P<0.0001). In patients with spinal tuberculosis, the QFT-GIT test sensitivity was 92.16% (95% CI: 80.25%-97.46%), and the specificity was 67.14% (95% CI: 54.77%-77.62%). The accuracy of diagnostic tests in the validation cohort increased from 77.42% to 80.65% when a new cutoff point was selected (1.58 IU/mL) from the ROC curve of the study cohort. The TB Ag-Nil values in tuberculosis patients were correlated with the duration of the patients’ disease (r=0.4148, P=0.0025).ConclusionThe QFT-GIT test is an important test for preoperative differential diagnosis of spinal tuberculosis with high sensitivity but low specificity. The diagnostic efficacy of the QFT-GIT test can be significantly improved via application of a new threshold (1.58 IU/mL), and the intensity of the QFT-GIT test findings in spinal tuberculosis may be related to the duration of a patient’s disease.

A predictive model for early clinical diagnosis of spinal tuberculosis based on conventional laboratory indices: A multicenter real-world study

“…Moreover, routine laboratory tests of inflammatory markers such as blood sedimentation, white blood cell count, and C-reactive protein are not specific for the diagnosis of tuberculosis, and these markers are also elevated in septic spondylitis (Liu et al, 2022). Interferon gamma release assays (IGRAs) have shown better diagnostic efficacy, as confirmed by our previously published study (Hu et al, 2022). However, we also observed that IGRAs alone do not meet the clinical need for diagnostic accuracy in spinal tuberculosis.…”

“…It is difficult to distinguish STB from septic spinal infections and some spinal tumors, which also manifest as bone destruction (Liu et al, 2021). IGRAs have been shown to be highly sensitive for the diagnosis of spinal tuberculosis (Hu et al, 2022) However, IGRAs have a low specificity for the diagnosis of STB due to their inability to differentiate between active and latent TB. Spine surgeons lack a tool that can be used for early differential diagnosis of spinal tuberculosis, leading to missed and misdiagnosed cases of spinal tuberculosis.…”

Identification of pathogen composition in a Chinese population with iatrogenic and native vertebral osteomyelitis by using mNGS

“…nafcillin or oxacillin) [ 22 ]. For NVO, antibiotic selection can be guided by the results of interferon-gamma release assays (IGRAs) [ 23 ]. If IGRAs are positive, consideration can be given to a four-drug regimen for antituberculosis therapy, while in cases where IGRAs are negative or results are not available, antibiotics effective against both Staphylococcus aureus and Mycobacterium tuberculosis , such as the combination of levofloxacin and rifampicin, may be used [ 24 ].…”

Screening of extra-pulmonary tuberculosis signature genes and analysis of correlation with immune cells

“…The diagnosis of EPTB lacks speci city (9). Interferon-gamma release assays (IGRAs) showed better diagnostic e cacy, which was con rmed by our previously published study (10), however, IGRAs alone still cannot meet the clinical demand for the diagnostic accuracy of EPTB. In addition, IGRAs cannot differentiate between active and latently infected tuberculosis; however, one-fourth of the world's population is latently infected with Mycobacterium tuberculosis, making IGRAs a limitation for the diagnosis of tuberculosis (11).…”