[Long-term observation of pulmonary Mycobacterium avium complex disease treated with chemotherapy-- following the guidelines for treatment].

OBJECTIVE: We performed a long-term retrospective investigation of pulmonary Mycobacterium avium complex (MAC) disease treated with combined chemotherapy following the ATS guideline or the Japanese Society for Tuberculosis guideline. We also studied when to terminate the combined chemotherapy. MATERIALS AND METHODS: The subjects of this study consisted of 90 patients who underwent combined chemotherapy according to these guidelines for minimum one-year period and followed up for at least one year since April, 1998. RESULTS: The mean patients' age was 64.8 years old and the gender distribution consisted of 34 males and 56 females. While the sputum negative conversion was observed in 54 of 90 patients (60%), clinical improvement was recognized in 35 patients (39%) following combined chemotherapy administered according to the guidelines. Out of 54 patients with sputum conversion, 30 cases were followed up after the discontinuation of treatment, and sputum relapse later was seen in 18 patients. Out of 24 patients who continued the same treatment, sputum relapse was seen in 10 patients. Out of 35 patients with clinical improvement, 17 cases have been followed up after the discontinuation of treatment, clinical worsening was later recognized in 9 patients. Out of 18 patients who continued the same treatment, clinical worsening was recognized in 6 patients. CONCLUSIONS: As the probability of sputum relapse after discontinuation of treatment was high even among patients whose sputum converted to negative by combined treatment according to the guidelines, we think that it is better to continue treatment according to the guidelines as long as possible.