| Popis: |
Until recently, the diagnosis of tuberculosis infection depended solely on the tuberculin skin test (TST), an imperfect test with known limitations. The most significant advance in recent times has been the development of T-cell-based interferon-gamma release assays (IGRAs). IGRAs are in-vitro blood tests that are based on interferon-gamma (IFN-γ) release after stimulation by TB specific antigens (e.g. ESAT-6 and CFP-10). Two IGRAs are currently registered for use in Canada – the QuantiFERON®-TB Gold In-Tube (QFT) assay (Cellestis Ltd., Carnegie, Australia), and the T-SPOT®.TB assay (Oxford Immunotec, Oxford, U.K.). “Interferon Gamma Release Assays for Latent Tuberculosis Infection” was published in Canada Communicable Disease Report 2007; 33 (ACS-10) on 1 November, 2007 as an Advisory Committee Statement (ACS) of the Canadian Tuberculosis Committee (CTC) (1). This was the first official recommendation from Canadian tuberculosis authorities on IGRAs, based on scientific literature published up to October 2006. The recommendations have been incorporated into the recently published 6th edition of the Canadian Tuberculosis Standards (2007) (2). Since the publication of the original ACS, a large number of IGRA studies have been published. In October 2008, updated version of the 2007 guidelines was published (Can Commun Dis Rep. 2008 October, 34(ACS-6):1-13.) (3). In December 2008, an expert group was constituted to prepare this second update. |
