System proteinase/inhibitors in the pathogenesis of experimental kidney tuberculosis

BACKGROUND: Damage to the kidney parenchyma of various origins is associated with the accumulation of extracellular matrix proteins, the regulation of which involves the matrix metalloproteinase/inhibitor system.

AIM: To evaluate the pathogenetic role of the proteinase/blood inhibitor system in experimental renal tuberculosis.

MATERIAL AND METHODS: When modeling the process, a clinical strain 5582 of the Beijing genotype with multidrug resistance of mycobacteria was used. The study was conducted on 20 rabbits, divided into three groups: the first (n=6) included infected untreated animals; in the second (n=7) and third (n=7) anti-tuberculosis therapy was administered orally for 18.5 weeks; in the third, treatment was carried out in combination with a single injection of autologous mesenchymal stem cells into the ear vein. Blood levels of matrix metalloproteinases-1 and -9, tissue inhibitor of metalloproteinases-1, cystatin C and neutrophil elastase were determined. Morphological changes in the kidney parenchyma at the end of the experiment were assessed using 26 indicators, including tubulointerstitial and vascular changes. The median and interquartile ranges were calculated, the Kruskal–Wallis test, analysis of covariance, and the projective classification method were used.

RESULTS: The progression of kidney tuberculosis was accompanied by a significant increase in the level of neutrophil elastase by 1.9 times, matrix metalloproteinase-9 by 2.2 times, and cystatin C by 1.5 times compared to the initial level. The treatment carried out in the second and third groups contributed to the normalization of these indicators. The concentrations of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in all three groups did not change relative to the baseline level. Covariance analysis showed that in the pathogenesis of renal tuberculosis changes in matrix metalloproteinase-1 (p=0.003), matrix metalloproteinase-9 (p=0.002), tissue inhibitor of metalloproteinases-1 (p=0.01) and cystatin C (p=0.0001) were primarily associated with vascular changes, found in all study groups. A linear combination containing three morphological characteristics allowed us to identify differences between the three groups with 90% accuracy.

CONCLUSION: Renal tuberculosis, caused by a multidrug-resistant pathogen, is characterized by an imbalance in the proteinase/inhibitor system and impaired renal function, the degree of which is associated with the morphological characteristics of vascular and tubulointerstitial changes.