Dendritic cells in the lung cavities of extensively drug-resistant tuberculosis patients exhibit altered frequency and phenotype

Background Studies examining dendritic cell (DC) immunobiology in tuberculosis (TB) patients have been conflicting, and no studies have examined DCs in the peripheral blood or lungs of patients with pre- or extensively drug-resistant TB (XDR-TB). Methods To provide insight into DC immunobiology, we first compared the DC subsets in the peripheral blood of XDR-TB patients with that from participants with latent TB infection (LTBI). Second, we compared DC subsets from cavity biopsies from explanted lung sections with normal-appearing lung tissue from pre-XDR/XDR-TB patients undergoing resection surgery. DCs were assessed for phenotypic and functional markers using flow cytometry. Results In the peripheral blood of XDR-TB patients, plasmacytoid DCs (pDCs) expressed lower levels of cluster of differentiation 83 (CD83; p=0.01), toll-like receptor 2 (TLR-2; p Conclusions The low frequency of cDCs in the lung cavity of XDR-TB patients in conjunction with the limited migratory and co-stimulatory expression of pDCs suggests that there is DC dysregulation in the lung mucosal milieu, possibly due to persistent disease.