The microbiological and clinical effects of combined therapy according to guidelines on the treatment of pulmonary Mycobacterium avium complex disease in Japan - including a follow-up study.

BACKGROUND: The difficulty of treatment for pulmonary Mycobacterium avium complex (MAC) in Japan.

OBJECTIVES: To investigate the clinical and microbiological effects of treatment according to the guidelines proposed by the American Thoracic Society and the Japanese Society for Tuberculosis and prospective follow-up studies after the completion of treatment of patients with pulmonary MAC disease.

METHODS: Analysis of the microbiological effects with regard to sputum conversion rate and the sputum relapsing rate and the clinical effects with regard to clinical symptoms and radiological findings for patients with pulmonary MAC disease treated with a regimen consisting of rifampicin, ethambutol, streptomycin, and clarithromycin over 24 months and follow-up over 12 months.

RESULTS: Sixty-five patients with pulmonary MAC disease were enrolled in this trial. In 39 patients, negative sputum conversion was observed within 6 months after the initiation of this regimen, 16 relapsed, and 20 experienced clinical worsening within 1 year after the completion of treatment. Although retreatment with the same regimen or a regimen including new quinolones was carried out for these patients, we could not achieve negative sputum conversion and/or clinical improvement.

CONCLUSIONS: We believe that the dose of clarithromycin for pulmonary MAC disease may be increased and recommend surgery for patients with a localized lesion at early-stage MAC disease to prevent a high rate of relapse.