The Role of Immunological Mechanisms in the Pathogenesis of Asthmatic Bronchitis in Children.

Abstract: The relevance of this article lies in the need to investigate the influence of high-altitude conditions on the pathogenesis of asthmatic bronchitis in children, which will improve therapeutic approaches to this disease. The aim of the study was to examine the associations between residential altitude and the immunological mechanisms underlying asthmatic bronchitis in children. A total of 240 children residing in low-altitude (880 m), mid-altitude (1400 m), and high-altitude (2468-3000 m) regions of southern Kyrgyzstan were examined, including 120 children with asthmatic bronchitis and 120 healthy children forming the control group. Pro-inflammatory and anti-inflammatory cytokines, lymphocyte subpopulations, oxidative stress markers, and antioxidant capacity were evaluated. Serum cytokine levels were determined using enzyme-linked immunosorbent assay (ELISA) with commercial Thermo Fisher Scientific kits. The results revealed significant differences in immune and respiratory parameters depending on altitude. High-altitude regions exhibited the most pronounced inflammatory response: IL-4 and IL-6 levels reached 18.2±2.3 pg/mL and 34.1±4.7 pg/mL, respectively, while IL-10 decreased to 10.8±1.2 pg/mL. The pro-inflammatory cytokine TNF-α was highest (25.6±3.5 pg/mL), indicating chronic inflammation. In low-altitude zones, pro-inflammatory activity was minimal. Analysis of ventilatory parameters showed a reduction in forced vital capacity (75.8±5.5%) and forced expiratory volume in the first second (70.2±4.9%) among high-altitude children, correlating with pro-inflammatory cytokine (r=-0.61, p<0.05) and malondialdehyde levels (r=-0.52, p<0.05). Diminished antioxidant defence (14.2±1.8 mmol/L) and greater hypoxic exposure were associated with increased oxidative stress and poorer pulmonary function. These findings highlight the importance of considering altitude and environmental factors when developing therapeutic strategies. Personalised treatment approaches are proposed, focusing on cytokine response modulation and oxidative stress reduction for children from high-altitude regions.