METHOD FOR PREDICTING PROGRESSION TO ACTIVE TUBERCULOSIS DISEASE

The invention provides a gene signature for use in determining a likelihood of a latent tuberculosis (TB) infection in a subject transitioning to active TB disease. The gene signature comprises at least SEPT4 and BLK, and optionally also GAS6 and/or CD1C. Expression levels of these genes are detected in a sample from the subject, and the ratios of expression of at least two of the above genes are calculated (e.g. SEPT4:BLK, SEPT4:CD1C, GAS6:BLK and/or GAS6:CD1C). A score is assigned to each ratio, the score being indicative of the likelihood of the latent TB infection transitioning into active TB disease, based on the ratio for the respective gene pair. The subject can be identified as having a latent TB infection that is likely to transition into active TB disease or that is not likely to transition into active TB disease based on the score or on the average of the scores.