In a study undertaken to investigate the effect of chemotherapy including RFP on cell mediated immunity of patients with pulmonary tuberculosis, the interferon producing ability of peripheral blood lymphocytes was assessed, with lymphocyte transformation (LTF) test, peripheral blood lymphocyte count, tuberculin reaction and PHA skin reaction done concurrently, before, 1 and 3 months after starting chemotherapy in 28 cases of pulmonary tuberculosis to compare the measurements with corresponding values for 8 healthy control subjects. The results obtained are summarized as follows:
1. The PPD-and PHA-induced production of interferon by peripheral blood lymphocytes was found inhibited at 1 month after starting chemotherapy but returned to the pretreatment level 2 months later.
2. LTF caused by stimulation with PPD was suppressed at 1 month after starting chemotherapy and was restored to the pretreatment level at 3 months.
3. No significant suppressant effect of the treatment was noted on PHA-induced LTF.
4. Neither tuberculin reaction nor PHA skin reaction was inhibited to an appreciable extent by the treatment.
5. No significant changes in peripheral blood lymphocyte count were observed during the treatment.
These results suggest that RFP might exert a transient suppressant action on cell mediated immune response. None of the RFP-treated cases showed deterioration of chest x-ray findings.
