[In vitro interferon-gamma induction in whole blood samples is a test for tuberculous infection in children and adolescents].

By applying the interferon-gamma (IFN-gamma) induction technique in the whole blood samples exposed to short-term (22-24-hour) incubation in the presence of Mycobacterium tuberculosis antigens--PPD tuberculin and specific recombinant ESAT-6 lacking in the cells of vaccine BCG and other non-tuberculous mycobacteria, the authors studied the groups of children and adolescents with a negative Mantoux test (n = 31), with postvaccine BCG allergy (n = 40), as well as patients with primary tuberculous infection (n = 84) and those with pulmonary tuberculosis (n = 44). Patients with primary tuberculous infection and a high sensitivity (94%) and a high specificity (97%) may be differentiated from children and adolescents with postvaccinal allergy when the recombinant ESAT-6 antigen and the critical IFN-gamma level (greater than 70 pg/ml) detectable in the plasma samples after incubation with the antigen. It has been also shown that in adolescents with local forms of pulmonary tuberculosis specific IFN-gamma induction may be suppressed in number of cases, which is ascribed to decreased specific immunity.