TY - JOUR T1 - Repeated tuberculin testing does not induce false positive ELISPOT results JF - Thorax JO - Thorax SP - 180 LP - 180 DO - 10.1136/thx.2005.049759 VL - 61 IS - 2 AU - L Richeldi AU - K Ewer AU - M Losi AU - P Roversi AU - L M Fabbri AU - A Lalvani Y1 - 2006/02/01 UR - http://thorax.bmj.com/content/61/2/180.1.abstract N2 - The Enzyme Linked ImmunoSpot (ELISPOT) is a new rapid T cell based blood test (otherwise known as an interferon-γ assay) for the diagnosis of latent tuberculosis infection.1–3 The commercially available form of the assay, T-SPOT® TB (Oxford Immunotec, Abingdon, UK) has European regulatory approval as an in vitro diagnostic test and is increasingly being used in clinical practice. The test is based on the enumeration of interferon-γ producing T cells which are specific for two highly antigenic proteins, early secretory antigenic target-6 (ESAT-6) and culture filtrate protein 10 (CFP-10).1 These proteins are expressed by Mycobacterium tuberculosis but are absent from M bovis BCG vaccine. Hence, the test does not give false positive results in BCG vaccinated individuals.1–3 ESAT-6 and CFP-10 are, however, contained within tuberculin purified protein derivative (PPD). Since ELISPOT is a highly sensitive method for measuring even low numbers of antigen specific T cells,4 concerns have been raised as to whether repeated tuberculin skin tests might induce T cell responses to these specific antigens, resulting in false … ER -