[Pulmonary tuberculosis and cutaneous anergy to tuberculin]

A negative tuberculin test in a bacilliferous subject is an apparently paradoxical situation, since the first penetration of tubercle bacilli into the human body is known to induce hypersensitivity to tuberculin and to enhance cellular immunity. These two facets of cutaneous reaction are most probably related to lymphocyte populations of two different phenotypes. The authors found that 21% of skin tests were negative in patients carrying tubercle bacilli, with a higher frequency in elderly people and in subjects with low serum albumin levels and/or biochemical hepatic alterations. Helped by the literature, they are wondering about the significance and possible mechanisms of this situation.