Introduction:
It is known that the level of tissue fibrosis factors, such as matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), significantly increases in destructive multi-drug-resistant tuberculosis (MDR-TB). Aldosterone can act as a fibrosis factor since its elevated levels contribute to excessive fibrosis. In addition, many of the patients with MDR-TB are smokers, which is known to have an adverse effect on the course of tuberculosis. The purpose of the study was to investigate the levels of tissue fibrosis factors in patients with destructive MDR-TB.

Methods:
One hundred and four patients with destructive MDR-TB were included in the study and divided into two groups: Group 1, 36 non-smokers; Group 2, 68 smokers. Levels of aldosterone, MMP-9 and TIMP-1 were evaluated by ELISA method in blood plasma at the treatment onset. Statistical data processing was performed in STATISTICA 8.0.

Results:
Significant difference between the two groups was found by comparing the aldosterone level: Group 1, 80.54±3.97 pg/mL, and 100.76±7.44 pg/mL in Group 2 (p=0.03). The difference between groups by MMP-9 and TIMP-1 levels was insignificant (p>0.05). MMP-9 level was 354.51±3.72 ng/mL in Group 1 and 355.39±5.81 ng/mL in Group 2. TIMP-1 level was 134.27±1.81 ng/mL in Group 1 and 123.70±4.58 ng/mL in Group 2. Sputum conversion at the 3rd month of treatment was observed in 96.78% patients in Group 1, which was significantly higher than in Group 2 (83.92%) (p<0.05).

Conclusions:
In the absence of significant differences in the levels of MMP-9 and TIMP-1, the level of aldosterone was significantly higher in smokers. Excessive fibrosis in a number of pathological conditions of the respiratory system is associated with high levels of aldosterone. It was found that a high level of aldosterone in smokers is a marker of later sputum conversion in patients with MDR-TB.