This paper presents the results of delayed-type skin reaction to tuberculin and the cellular and humoral immune responses "in vitro" in 50 patients with active pulmonary tuberculosis admitted to the "Parque Hospitalar do Mandaqui", São Paulo, Brazil, in the period from May to August 1980, matched for sex and ranging in age from 20 to 80 years old. In order to study the delayed-type skin reaction to tuberculin, the PPD, Rt-23, 2 TU (Purified protein derivative) was used and the result obtained was of 14.0% of nonreactors, 12.0% of weak reactors and 74.0% of strong reactors. The "in vitro" study of cellular and humoral immune responses was carried out by determining the number of T and B lymphocytes, the lymphocyte transformation, the liberation of the leucocyte inhibitor factor (LIF) and by the passive hemaglutination test. The results showed the importance of calculation of the absolute number of T and B lymphocytes. The culture of lymphocytes and the LIF experiment were able to detect the lymphocyte sensitivity to PPD even in the nonreactor patients and the passive hemaglutination test showed the presence of specific antibodies in the population studied demonstrated by the highest titers when compared with normal subjects, independently of the skin reactivity to tuberculin.
Tuberculosis, pulmonary; Tuberculin test
