Fig. 4. .

Differences in the change in antibody levels in sera from patients infected with isoniazid-sensitive and isoniazid-monoresistant strains of M. tuberculosis. These graphs include data from only those patients with smear-positive pulmonary tuberculosis who had a positive antibody titer at some point during their treatment (i.e., 207 of 240, being 40 patients multiplied by 6 antibody measurements of different specificity). Seven patients with isoniazid-resistant tuberculosis are compared to 33 patients infected with fully sensitive strains of M. tuberculosis. Antibody levels obtained during treatment were each compared to the patient's pretreatment level to give a relative antibody titer. The relative antibody titers to all six epitopes were then combined to give a mean ± standard error. A logarithmic scale has been used to treat rises and falls in antibody titer equally. TB, tuberculosis.