The vitamin D status and the levels of β1- and β2-defensins in children and adolescents with different forms of pulmonary TB

Introduction. The basic research demonstrated an important role of vitamin D in strengthening the immune response to Mycobacterium tuberculosis and proved its effect on the production of antimicrobial peptides. However, the correlation between the levels of vitamin D and defensins ( β 1 and β 2) in children and adolescents with different forms of pulmonary TB was not studied. Aim. To study the correlation between the levels of vitamin D and β 1- and β 2-defensins in children and adolescents with different forms of pulmonary TB. Materials and methods. We carried out a prospective study of 75 patients with pulmonary TB aged 2–17 years (52 new cases and 23 retreatment cases) in 2021–2023. The levels of 25(OH)D and β 1- and β 2-defensins were determined at admission to hospital. Results. Out of 75 patients 2.7% had adequate levels of vitamin D (more than 30 ng/mL), 13.3% had insufficient levels of vitamin D (20 to 30 ng/mL), 34.7% had deficient levels of vitamin D (10 to 20 ng/mL), and 49.3% had severe deficiency of vitamin D (less than 10 ng/mL). We established a direct correlation between 25(OH)D and β 1-defensin levels (p = 0.004766) and lack of correlation between 25(OH)D and β 2-defensin levels. We discovered significant differences in the levels of 25(ОН)D and β1-defensin between new and retreatment cases: 13.10 ± 1.04 ng/mL and 8.74 ± 1.07 ng/mL (p = 0.004644) and 6.66 ± 0.79 ng/mL and 4.0 ± 0.85 ng/mL (p = 0.024816), respectively. Conclusion. The differences in the levels of calcidiol and β 1-defensin between new and retreatment cases witness an impaired function of one of the innate non-specific immunity components during long-lasting advanced pulmonary TB in children and adolescents.