The value of combined detection of Mycobacterium tuberculosis-specific cytokines IFN-γ and IL-2 in the auxiliary diagnosis of superficial lymph node tuberculosis

Superficial lymph node tuberculosis (SLNTB) represents a prevalent form of extrapulmonary tuberculosis (EPTB). The imperative need for an early diagnosis of this condition underscores the significance of developing a straightforward, minimally invasive, and highly efficacious detection modality. This study aims to assess the diagnostic utility of the combined detection of cytokines IFN-γ and IL-2 stimulated by Mycobacterium tuberculosis (MTB)-specific antigens in the diagnosis of SLNTB. A retrospective cohort study comprising 104 individuals with SLNTB and 72 individuals with non-tuberculous lymph node enlargement, who presented at the hospital simultaneously, was enrolled in this investigation. Peripheral blood mononuclear cells (PBMCs) isolated from these subjects were stimulated with the specific protein ESAT6-CFP10-Rv1985c of MTB to ascertain the concentrations of IFN-γ and IL-2. This facilitated the assessment of the combined diagnostic efficacy of these two cytokines. Furthermore, PBMCs were stimulated with ESAT6-CFP10 to measure IFN-γ levels, enabling a comparative analysis of the stimulatory effects of different fusion proteins. The combined detection of MTB-specific cytokines IFN-γ and IL-2 exhibited a sensitivity of 88.5%, a specificity of 87.5%, and an AUC of 0.947. Incorporating IL-2 as a detection target resulted in a 4.8% increase in sensitivity. The sensitivity of utilizing ESAT6-CFP10 as a stimulating protein to detect IFN-γ was 77.9%, significantly lower than that of the combined detection of IFN-γ and IL-2, while specificity did not show a statistically significant difference. The combined detection of MTB-specific cytokines IFN-γ and IL-2 demonstrates significant utility in the auxiliary diagnosis of superficial lymph node tuberculosis. The combined detection of MTB-specific cytokines IFN-γ and IL-2 demonstrates significant utility for SLNTB diagnosis.