International Journal of Medicine and Data

Objective To investigate the changes in CRP and cytokine expression levels in the peripheral blood of patients with negative pathogen tests and negative IGRA and their clinical significance. Methods Two hundred and ninety-five cases hospitalized in the Infectious Diseases Hospital affiliated with Soochow University between October 21, 2021 and April 27, 2023 were included. Based on the diagnostic criteria for tuberculosis (WS288~2017), 196 cases of tuberculosis patients were included, including 130 males and 66 females, with a mean age of 58.4±17.1 (years); 92 cases of bacteriophage-positive tuberculosis patients and 104 cases of bacteriophage-negative tuberculosis patients; among the bacteriophage-negative tuberculosis (pathogen test-negative) patients, there were 44 cases of IGRA-positive patients and IGRA-negative patients 14 cases. The disease control group included 79 patients with pneumonia, including 51 males and 28 females, with a mean age of 61.8±15.4 (years). The healthy control group included 20 cases, of which 10 were male and 10 were female, with a mean age of 58.6±6.3 (years). The expression of cytokines (IFN-γ, IFN-α, IL-2, IL-4, IL-5, IL-6, IL-8, TNF-α, IL-10, IL-12P70, IL-1β, IL-17) and CRP in the peripheral blood were detected by flow cytometry and immunofluorescence dry-quantification, respectively, and the expression differences of inflammatory cytokines and CRP in different groups were analyzed. Results ①Peripheral blood levels of IFN-γ, CRP, and IL-6 were significantly higher in bacteria-positive TB patients than in bacteria-negative TB patients, and peripheral blood levels of IFN-γ, CRP, and IL-6 were significantly higher in bacteria-negative TB patients than in healthy controls, with P <0.0001, 0.0006, and <0.0001, respectively. ②Peripheral blood levels of IFN-γ, CRP, and IL-6 were significantly higher in IGRA-negative patients with mycobacterium-negative tuberculosis than in healthy controls, with P of 0.0002, 0.0043, and <0.0001, respectively. ③Using the healthy control group as a reference, the AUC under the ROC curve of IFN-γ combined with CRP and IL-6 in bacteria-negative tuberculosis patients with IGRA-negative patients was 0.957, and its sensitivity and specificity were 92.9% and 100%, respectively. ④Using the disease control group as a reference, the AUC under the ROC curve for IFN-γ combined with CRP , IL-6 in bacteriophage-negative TB patients with IGRA-negative patients was 0.736, and the sensitivity and specificity were 50% and 89.9%, respectively. Conclusions In patients with clinically suspected symptoms of tuberculosis and highly supportive imaging, peripheral blood IFN-γ combined with CRP and IL-6 testing may provide an adjunctive diagnosis for this group of patients with suspected tuberculosis when there is no basis for an aetiologic diagnosis and IGRA is negative.

Tuberculosis; Professional pneumoconiosis; IFN-γ; CRP; IL-6