Hong Y, et al. - Researchers investigated the levels of vitamin D-related cytokines in cases with active tuberculosis (TB) vs latent TB infection (LTBI). They measured plasma 25-hydroxyvitamin D (25[OH]D), IL-15, IL-32, and IL-1β levels in total, 50 TB-infected patients (25 with active TB and 25 with LTBI following a TB outbreak in a high school) via enzyme-linked immunosorbent assays. Active TB patients and LTBI subjects were noted to differ in the levels of the vitamin D-related cytokines IL-15 and IL-32. Patients with active TB displayed lower plasma 25(OH)D and plasma IL-15 levels than in LTBI subjects. Furthermore, in QuantiFERON TB Gold-In-Tube (QFT-GIT) supernatants, the plasma 25(OH)D levels associated positively with the level of unstimulated IL-15 and negatively with that of TB antigen-stimulated IL-32. They suggest the utility of these data as basic data for developing biomarkers distinguishing between active TB and LTBI.