Determining the probable role of ferroptosis in the course of inflammatory bacterial diseases of the respiratory organs in young children accompanied by the development of anemia of inflammation

Abstract

Aim. To determine the probable role of ferroptosis in the course of inflammatory bacterial diseases of the respiratory system in young children, accompanied by the development of anemia of inflammation. Materials and methods. The study included 62 children (mean age 1.4 ± 0.4 years). The main group included 42 children with acute inflammatory bacterial diseases of the respiratory system, accompanied by anemia of inflammation: 29 children were diagnosed with bacterial bronchitis, 13 children – pneumonia. Determination of the severity of inflammatory diseases was determined by Acute Bronchitis Severity Score and Pediatric Respiratory Severity Score. At the time of participation in the study, all patients under observation had no signs of impaired iron metabolism, including iron deficiency anemia, in the anamnesis. The control group included 20 relatively healthy children. The content of caspase-7, caspase-9, ferritin, nitrotyrosine, phospholipase A2 was determined by ELISA using commercial kits. Results. We hypothesized the ineffectiveness of apoptosis in the course of bacterial inflammatory processes of the respiratory organs in young children, accompanied by the development of anemia of inflammation, and studied the probability of ferroptosis in these conditions. The obtained data indicated the presence of active oxidative stress in the main group patients. The strong direct correlation between the severity of inflammatory disease and the intensity of oxidative stress was revealed (r = 0.7, P < 0.001). A statistically significant increase in ferritin content in the main group compared with the control group was observed. There was a strong direct correlation between ferritin levels and the severity of bronchitis (r = 0.82, P < 0.01) and the severity of pneumonia (r = 0.87, P < 0.01). It was found that the upper quartile of serum ferritin levels (73.2 ± 4.6 ng/ml) was associated with severe disease. We assumed that restriction of access to iron for bacterial pathogens due to its sequestration in cells is a pathological process under certain conditions. Conclusions. In the pathogenesis of bacterial inflammatory diseases of the respiratory organs in young children, accompanied by the development of anemia of inflammation, the processes of apoptosis did not dominate, but, obviously, necrotic phenomena did, including ferroptosis as one of the manifestations of necrosis. The protective mechanism aimed at limiting the access of bacterial pathogens to iron due to its sequestration in cells becomes pathological under certain conditions.