Can the new diagnostic tools help in HIV-infected children with presumed TB?
Data published up till now indicate that these blood-based tests are more likely to be positive in HIV-infected children than the skin test, which is encouraging and could be extremely helpful. A large study or children in South Africa by Liebeschutz et al (16) showed that 73 % of HIV-infected children with confirmed TB had a positive T spot, as compared to 35% in the skin test. Howevr, no CD4T cell counts were measured in this study, so we can not be sure of the level of immunosuppression in the children. Another recent paper by Dheeda et al (17) showed again good performance of the T spot assay in HIV-infected adults with a variety of CD 4 counts, as compared to the skin test, but this study only mentioned the responses to the non-specific stimulus, PHA, and not the specific antigens. No data are published on the use of the Quantiferon test in HIV as yet, but several studies are ongoing. If the blood based tests turn out to be quite specific, they will at least help us to detect the
