CHEMOTHERAPY EFFECTIVENESS IN NEWLY DIAGNOSED PATIENTS WITH MULTIDRUG-RESISTANT PULMONARY TUBERCULOSIS CAUSED BY DIFFERENT M. tuberculosis GENOTYPES IN THE SAKHA REPUBLIC (YAKUTIA)

Objective: to study the clinical course and chemotherapy effectiveness in newly diagnosed patients with multidrugresistant (MDR) pulmonary TB caused by different genotypes of M. tuberculosis in the Sakha Republic (Yakutia). Materials and methods. We carried out a retrospective analysis of treatment outcomes in 107 patients with newly diagnosed microbiologically confirmed MDR TB. M. tuberculosis complex DNA was detected in sputum specimens by real-time polymerase chain reaction (RT-PCR) to differentiate between Beijing and non-Beijing strains. Results. The majority of strains belonged to the Beijing family (63.5%); the others were referred to non-Beijing genotypes (36.5%). We studied the clinical course and chemotherapy effectiveness in two groups – patients with TB caused by Beijing strains (group 1) and patients with TB caused by strains other than Beijing (group 2). Infiltrative TB prevailed in both groups, the share of cases with disseminated TB was significantly higher in group 1. Drug resistance patterns were as follows: co-resistance to first- and second-line drugs in 54.4% of patients in group 1 and 15.4% of patients in group 2. The clinical course of pulmonary TB was more severe in group 1. Upon chemotherapy completion sputum conversion was achieved in 69.1% and cavity closure – in 63.1% (in half of cases surgery was involved) of patients in group 1. While in group 2 sputum conversion was achieved in 92.3% and cavity closure – in 90.9% of patients. Treatment failure was registered in 22.1% of patients with TB caused by Beijing strains, 8.8% of patients died from TB. Conclusion. The obtained results witness that patients with pulmonary TB caused by Beijing strains have a more severe course of the disease with pronounced intoxication and bronchopulmonary syndromes, high incidence of cavities, and low chemotherapy effectiveness.