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Utility of QuantiFeron -TB® Gold test in diagnosis of tuberculosis in HIV-infected patients
Magdalena Dinu, Mihaela Iosipenco, Carmen Craciun, Cristian Baicus, Ruxandra Neagu Draghicenoiu, Lucian Gavrilă
Abstract: HIV is a risk factor for passage from latent tuberculosis to an active form of the disease. In HIV seropositive patients after infection with Mycobacterium tuberculosis, the number of TCD4+ decreases drastically for a short period of time and the HIV viral loads (VL) increase. Theoretically, because of the decreased number of TCD4+ and TCD8+ in HIV infection, QuantiFeron test (QFT) is not useful for diagnosis of BK co-infection. When the number of CD4+/CD8+ cells is low, the level of IFN-gamma released by lymphocyte stimulation is too low to be meaningfully evaluated by an ELISA test. The aim of our study was to determine the influence of immunodepression in HIV infected patients on the utility of QuantiFERON®-TB test in diagnosis of co-infection with Mycobacterium tuberculosis. No correlation between HIV viral load and TCD4+/TCD8+ count was revealed in our study. The percent of indeterminate results increased along with increases of viral load. A good response for QuantiFeron TB-Gold test was identified in patients with a TCD4 count higher than 95/µl. Since the test result was indeterminate for more than 10% of patients even in subjects with CD4 count higher than 95/µl, its potential as rule-out test for active TB disease is limited.
Keywords: QuantiFeron-TB Gold test,viral load,TCD4+/TCD8+count
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Dinu M, Iosipenco M, Craciun C, Baicus C, Neagu Draghicenoiu R, Gavrilă L. Utility of QuantiFeron -TB® Gold test in diagnosis of tuberculosis in HIV-infected patients. Rev Romana Med Lab. 2009;17(4):31-6
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