In peripheral blood stimulated with PPD, we found a significant increase in the frequency of MDSCs (HLA-DR-/lowCD14+CD15-CD33+) in patients with active TB (median = 42.2%; IQR: 28.1–56.3) compared to participants with LTBI (median = 8.2%; IQR: 7.6 – 10.2; p < 0.001; Figure 1). Here, FUT4 is linked to tuberculosis.