CD4 and tuberculosis: HIV-TB co-infected adults with low CD4 counts have been shown to have less extensive CXR changes at TB diagnosis, due to impaired localised cellular immune responses to mycobacterial infection, and our data suggest that this translates into less extensive residual pathology at TB treatment completion.34 35 However, it is of note that although the burden of disease was lower among HIV-positive compared with HIV-negative adults, still moderate-to-severe bronchiectasis or abnormal spirometry was seen in a third of this group at pTB treatment completion.