[Clinical characteristics of the patients with primary infection of Mycobacterium avium complex]

Clinical characteristics are analyzed in patients with primary infection of Mycobacterium avium complex (MAC). The definition of primary infection of MAC are determined as follows; 1) MAC is found several times since the beginning of the disease, 2) clinical symptoms or abnormal shadow corresponding to MAC infection on chest roentgenogram, 3) no old tuberculous lesions nor other abnormal shadows like bronchiectasis, 4) no abnormal serological results suggesting other bacterial or viral infections. According to this definition, 17 out of 84 MAC patients are diagnosed as primary MAC infection, and clinical features are analyzed in these 17 patients. Average age of patients is 61.1 +/- 12.9 year old. This age is significantly higher than that of inpatients with pulmonary tuberculosis in our hospital, and lower than that of all MAC patients including secondary infection. Five (29.4%) are male and 12 (70.6%) are female, the ratio of male to female is 1 to 2.4. This value is significantly different with that of inpatients with pulmonary tuberculosis in our hospital who show about 3 to 1. Most of the patients complained of cough with sputum, especially of hemosputum. Eleven out of 17 patients (64.7%) complained repeated hemosputum. The frequency of hemosputum is very high compared with that of the patients with pulmonary tuberculosis (about 20%). No compromised condition was present except for a patient with Behçet's disease who are taking steroid hormone. Roentgenographic features of primary infection are those of scattered small nodular lesions in the peripheral part of the lung, thin wall cavity formation, no contraction of the diseased lung nor dislocation of the trachea.(ABSTRACT TRUNCATED AT 250 WORDS)