Abstract:

Objective: To analyze clinical characteristics and prognosis of pulmonary diseases caused by Mycobacterium kansassi (M.kansassi) and Mycobacterium intracellular (M.intracellular), and to improve awareness of pulmonary disease caused by slow-growing mycobacteria. Methods: Medical records of 87 patients with M.kansassi pulmonary diseases and 285 patients with M.intracellular pulmonary diseases diagnosed in Shenzhen Third People’s Hospital from January 2017 to January 2021 were retrospectively reviewed. Demographic information, clinical manifestations, treatment, and sputum negative conversion between the two groups were compared and analyzed. Results: Patients with pulmonary disease caused by M.kansasii were predominantly male (18-45 years old, 81.6% (71/87)) and young adults (44.8% (39/87)), while patients with pulmonary disease caused by M.intracellulare were predominantly female (46-65 years old, 67.4% (192/285)) and middle-aged (50.9% (145/285)). The differences in the distribution of gender and age between the two groups were statistically significant (χ²=64.863, 22.243, respectively, both P<0.001). M.kansasii tuberculosis patients complicated with bronchiectasis were significantly less than those M.intracellulare tuberculosis (5.7% (5/87) vs. 33.7% (96/285), χ²=26.301, P<0.001), and the number of M.kansasii tuberculosis patients receiving treatment was significantly higher than that of M.intracellulare tuberculosis patients (75.9% (66/87) vs. 42.5% (121/285), χ²=29.754, P<0.001). The main drugs for M.kansasii tuberculosis patients were ethambutol (87.9% (58/66)), rifampicin (86.4% (57/66))and isoniazid (57.6% (38/66)), while the main drugs for M.intracellulare tuberculosis patients were rifampicin (83.5% (101/121)), ethambutol (77.7% (94/121)) and macrolides (70.2% (85/121)). The sputum culture conversion rate of M.kansasii tuberculosis patients who received treatment was significantly higher than that of M.intracellulare tuberculosis patients receiving treatment (87.9% (58/66) vs. 59.5% (72/121), χ²=16.816, P<0.001). The difference of adverse drug reactions of the two groups was was not significantly (24.2% (16/66) vs. 31.4% (38/121), χ²=1.067, P=0.302), and all the adverse drug reactions were mild. Conclusion: M.kansasii tuberculosis patients are more common in males and young adults, with rare complications such as bronchiectasis and underlying diseases, more likely to receive treatment, have shorter treatment duration, and have good treatment effect; while M.intracellulare tuberculosis patients are more common in females and middle-aged and elderly, and have poor treatment effect, it is necessary to explore new treatment strategy for patients with M.intracellular pulmonary disease.

Key words: Mycobacterium kansassi, Mycobacterium intracellular, Mycobacterium infections,lung disease, Disease attributes, Treatment outcome