Specific Cytokines Analysis Incorporating Latency-Associated Antigens Differentiates Mycobacterium tuberculosis Infection Status: An Exploratory Study

Abstract

Yuanchun Li,1,* Zhengrong Yang,1,* Qiping Ge,2 Yueqiu Zhang,1 Mengqiu Gao,2 Xiaoqing Liu,1,3,4 Lifan Zhang1,3,4 1Division of Infectious Diseases, Department of Internal Medicine, State Key Laboratory of Complex Severe and Rare Disease, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China; 2Department of Tuberculosis, Beijing Chest Hospital, Capital Medical University/Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, People’s Republic of China; 3Clinical Epidemiology Unit, Peking Union Medical College, International Clinical Epidemiology Network, Beijing, People’s Republic of China; 4Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Lifan Zhang; Xiaoqing Liu, Email [email protected]; [email protected]: Current immunologic methods cannot distinguish Mycobacterium tuberculosis (Mtb) infection statuses, especially to discriminate active tuberculosis (ATB) from latent tuberculosis infection (LTBI). This study explored the potential of latency-associated antigens (Rv1733cSLP and Rv2028c) and multifactorial cytokine detection to distinguish tuberculosis infection states.Methods: ATB patients (20), LTBI healthcare workers (25), fever patients (11), and healthy controls (10) were enrolled. Cytokine levels (IFN-γ, TNF-α, IL-2, IL-6, IP-10, IL-1Ra, CXCL-1, and MCP-1) were measured using Luminex with/without MTB-specific virulence factor and latency-associated antigens stimulation.Results: Without antigen stimulation, IL-6, IP-10, MCP-1, and IL-1Ra were higher in the ATB group than in the LTBI group (p< 0.05), but no significant differences between the ATB group and the fever group. Stimulated with the four antigens, respectively, the cytokines, including IP-10Esat− 6, IP-10CFP− 10, IFN-γRv1733cSLP, IFN-γRv2028c, IL-6Esat− 6, IL-6Rv1733cSLP, IL-6Rv2028c, IL-2Rv1733cSLP, IL-2 Rv2028c, IL-1RaEsat− 6, IL-1RaCFP− 10, IL-1RaRv2028c, CXCL-1Esat− 6, CXCL-1CFP− 10, CXCL-1Rv1733cSLP, CXCL-1Rv2028c, MCP-1Esat− 6 and MCP-1CFP− 10, demonstrated accurate discrimination between ATB and LTBI (p< 0.05). Additive concentrations demonstrated significant secretion differences of IFN-γ, IP-10 and IL-2, primarily by virulence factors in ATB and latency-associated antigens in LTBI. Latency-associated antigens synergized with virulence factors, enhancing TH1-type cytokine diagnostic efficacy for discriminating ATB from LTBI, the AUC for TNF-α increased from 0.696 to 0.820 (p=0.038), IFN-γ increased from 0.806 to 0.962 (p=0.025), and IL-2 increased from 0.565 to 0.868 (p=0.007). Model selected by forward likelihood method indicated combined detection of IFN-γCFP− 10, IFN-γRv1733cSLP, IP-10Rv1733cSLP, and CXCL-1Rv1733cSLP achieved ATB diagnosis (AUC=0.996) and ATB-LTBI differentiation (AUC=0.992). Combined detection of IFN-γCFP− 10 and IFN-γRv1733cSLP achieved tuberculosis infection diagnosis (AUC=0.943).Conclusion: Latency-associated antigens enhance multiple cytokine discriminatory ability, particularly TH1-type cytokines, for differentiating Mtb infection statuses.Keywords: active tuberculosis, cytokine, latent tuberculosis infection, latency-associated antigen, Mycobacterium tuberculosis, virulence factor

Keywords

• active tuberculosis
• cytokine
• latent tuberculosis infection
• latency-associated antigen
• mycobacterium tuberculosis
• virulence factor;