In the subsequent validation cohort analysis, we identified that the AUC of MCP-1 in diagnosing ATB and differentiating ATB from LTBI were 0.97 and 0.89, respectively, which was generally consistent with the results of the discovery cohort.
The monocyte chemotactic protein-1 (MCP-1) is a chemokine that plays an important role in the recruitment of monocytes to M. tuberculosis infection sites, and previous studies have reported that genetic variants in MCP1 are associated with differential susceptibility to pulmonary tuberculosis (PTB).
Our findings suggest that persons bearing the MCP-1 genotype GG produce high concentrations of MCP-1, which inhibits production of IL-12p40 in response to M. tuberculosis and increases the likelihood that M. tuberculosis infection will progress to active pulmonary tuberculosis.