[Tuberculin sensitivity in old children with new-onset active tuberculosis].

In recent years, there have been reports on the reduced diagnostic value of a tuberculin test with 2 TE PPD-L. Tuberculin diagnosis is a ground for suspecting tuberculosis only in 25.9 +/- 0.06% of cases in senior pupils and in 10.7 +/- 0.03% amongst adolescents. This is associated with the higher proportion tuberculin-positive individuals and it is very difficult to make the diagnosis in children with monotonous tuberculin sensitivity. A contact with a bacterium-discharging person undoubtedly increases a risk for the disease, but fails to affect the true outcome of delayed hypersensitivity. According to the date of this study, comorbidity and helminthic invasion have no significant impact on tuberculin sensitivity. Reactivation impairs immune homeostasis towards inadequate immune system performance.