Abstract

BLANCO, J.R. et al. Determination of antibodies against A-60 antigen for diagnosis of M. tuberculosis infection: An useful tool for rationalizing of chemoprophylaxis in HIV patients. An. Med. Interna (Madrid) [online]. 2001, vol.18, n.3, pp.23-27. ISSN 0212-7199.

Objective: To identify M. tuberculosis infection in HIV patients by use of PPD and an ELISA test detecting the presence of antibodies against antigen A-60 of M. bovis. Methods: 116 incoming HIV patients were classified according to the CDC. The status of M. tuberculosis infection was probed with PPD (RT-23) and the state of anergy was estimated by a Multitest CMI (Multitext®). The presence of circulating antibodies of the IgG class against antigen A-60 was analysed by an ELISA. The clinical course of the patients was followed for 24 month. Results: A positive serology (A-60) was found in 52.58% of the patients, coinciding with 70.45% of the positive PPD (p<0.003). This statical observation was found when we studied all of the individuals, and those with more than 500 CD4 lymphocytes. The Multitext® was positive in 11.11% of the patients with PPD (-), all of them without antibodies against A-60. However, 42.2% of the aptients who were PPD and Multitext® (-), had circulating antibodies against A-60. The following up of the patients during 24 months allowed the detection of 7 news cases of pulmonary tuberculosis, 4 of them had a positive A-60 serology, and 4 were anergy.  Conclusions: HIV patients with M. tuberculosis infection have circulating antibodies against A-60 antigen of M. bovis with independence of their immunity status. In anergic patients the presence of this antibodies can be an useful tool for rationalizing the prophylaxis against M. tuberculosis. A seropositivity (A-60) indicates as well as does PPD a previous contact with M. tuberculosis.

Keywords : A-60 antigen; HIV; Tuberculosis; M. tuberculosis infection; Anergy.

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