CD4+CD25+FoxP3+ T cells (Tregs) frequency in TB patients. (a) Plot of cytometric analysis from a representative sample: (I) FSC and SSC identifying mononuclear cells, (II) CD4+ cells within the lymphocyte gate, (III) assessment of FoxP3+ cells gated on the CD4+ cells as shown in panel II, (IV) isotype control from the same sample, and (V) an additional control showing that the CD4+FoxP3+ population is also CD25 high. (b) Treg % comparisons between HCo and TB. (c) Comparisons of disease severity of TB patients. Box plots show median values, 25–75 percentiles of data in each group with maximum and minimum values. HCo: healthy controls.