Immune status in tuberculosis and response to treatment

Thirty hospitalized patients with newly diagnosed tuberculosis were studied prospectively with a range of in vitro and in vivo tests of immune function. Responses were compared with those of healthy controls matched for age, sex, ethnic group and diet. A series of metabolic and immunologic abnormalities was found, including evidence of undernutrition, anaemia, neutrophil leucocytosis, monocytosis, lymphopenia, hyperglobulinaemia and raised erythrocyte sedimentation rate. Some patients had accelerated, others diminished, cutaneous tuberculin hypersensitivity, and some had diminished mononuclear cell proliferative and lymphokine responses to tuberculin (purified protein derivative, PPD). The patients were not uniform in their responsiveness, but could be arranged within a spectrum which showed a relationship to crude bacillary excretion and response to treatment. 27% of patients were characterized by hypersensitivity, with normal in vitro cellular responses and skin tests to PPD, scanty bacillary excretion and rapid bacteriologic sputum conversion to negative cultures with treatment. In contrast, 30% of patients were relatively anergic with negative skin tests, reduced or absent in vitro cellular reactivity to PPD, moderate or heavy bacillary excretion and later (greater than 4 weeks) bacteriologic sputum conversion. The remainder of the patients fell between these two groups. There were no correlations between cellular immunity on the one hand, and radiological extent of disease, levels of serum immunoglobulins, peripheral white cell counts or ESR on the other. In those patients followed throughout treatment, all the abnormalities with the exceptions of arm muscle circumference and serum albumin, reverted to the normal ranges established in the control group.