Patients with non-tuberculous mycobacteriosis in clinical practice

Incidence and prevalence of non-tuberculous mycobacteriosis (NTM) are recorded in many countries, but the rates vary. There are no official statistics on the prevalence and incidence of NTMs in the Russian Federation at the moment. The regulatory and expert clinical database for NTMs has not yet been developed. The aim of thе article is to share the experience of the Federal State Scientific Institution “Central Research Institute of Tuberculosis” (FSSI “CRIT”) in working with patients with NTMB over the past 7 years. Methods. The study included 190 patients with a confirmed diagnosis of NTMB who were treated at the FSSI “CRIT” in 2011 – 2018. Before the diagnosis of NTMB, all patients were followed for a long time by various specialists (pulmonologists, general practitioners) for various chronic respiratory diseases. NTMs were isolated from the diagnostic material by the culture method. The material was inoculated into a liquid medium in an automated BACTEC MGIT 960 system and into Levenshtein – Jensen dense medium until the culture growth was obtained. The HTM species was determined using DNA strips GenoType® Mycobacterium CM by Hain Lifescience (Germany). Results. More than half of the examined patients were registered with a phthisiatrician for various clinical forms of pulmonary tuberculosis (disseminated, fibro-cavernous, focal). In 85.6% of cases, no MBT DNA was found in the sputum and skin tests with recombinant tuberculosis antigen (Diaskintest®) were negative. Nevertheless, the changes in the lungs detected on the chest CT and even a single detection of acid-fast microorganisms (AFB) without typing led to an erroneous diagnosis of tuberculosis. In some patients (6.8%), a combination of pulmonary tuberculosis and NTMB was diagnosed. Bronchiectasis and COPD were the most common chronic nonspecific lung diseases. 66.7% of the patients had centrilobular foci characterized by the involvement of not only the bronchial wall but also the pulmonary vessels. NTMB resistance to a wide range of antibacterial drugs was determined in 118 patients (out of 190). The prolonged use of chemotherapy drugs revealed a wide range of drug intolerance. Side effects were handled in various ways: drug replacement (with consideration to the sensitivity), temporary withdrawal, and drug discontinuation. Conclusion. This work reflects the long-term experience of the FSSI “CRIT” staff with patients with NTMs, which can be used in creating national recommendations on NTMs.