[A clinical study on cases with pulmonary M. avium complex (MAC) disease followed up for more than 10 years]

We performed a clinical study on 22 cases with pulmonary M. avium complex disease followed up for more than 10 years. The mean age of these patients at the first visit was 60.1 years old and the extent of the disease among them was minimum or moderate. The progression of the disease was relatively slow. There were 5 cases of tuberculosis-like type and 11 cases of nodular-bronchiectasis type among the primary infection type and 6 cases of the secondary infection type. Classifying these cases by the grade of progression on chest X-ray findings, 2 cases improved, 11 cases slightly progressed, 4 cases moderately progressed and 5 cases severely progressed. Seven cases of the nodular-bronchiectasis type of the primary infection type were observed among 11 slightly progressed cases. This suggested that the prognosis of cases with nodular-bronchiectasis type was relatively good. The frequency of a reaggravation of chest X-ray findings was significantly higher in the severely progressed cases than in the slightly and moderately progressed cases. Generally, the number of used drugs was more and the duration of treatment was longer in the severely progressed cases. This suggested that these cases were intractable. The results of sputum culture for M. avium complex were consistent with the progression of the disease shown on chest X-ray findings among many cases. However, sputum culture negative was observed in some cases with the nodular-bronchiectasis type in spite of the reaggravation on chest X-ray findings. On the other hand, there were some cases in which few reaggravation was observed in spite of continued sputum culture positive. Based on these results, we made some remarks on the treatment and management of pulmonary M. avium complex disease.