Phagocytic activity of neutrophil blood granulocytes in children with chronic non-specific lung diseases with post-inflammatory pneumofibrosis

One of the reasons for the development of chronic forms of lung diseases and pneumofibrosis as a pathological outcome of this inflammation may be an insufficient immune response. The key position belongs to neutrophilic granulocytes. Given the importance and renewed interest in neutrophils as tools for regulating immunity, leading to the progression of the fibrous process in children with CKD is an urgent problem. The purpose of the study was to study the phagocytic activity of blood neutrophils as an important component of innate immunity in patients with CNLD. Seventy children with CNLD with focal or segmental post-inflammatory pulmonary fibrosis were examined. Of these, 27 were children with progression of PPF (main group) and 43 children with PPF without progression (comparison group). The controls were the indicators of 23 healthy children, comparable by gender and age. The studies were carried out during clinical remission. The phagocytic activity of neutrophils (PНAN), phagocytic number (PN), spontaneous and stimulated NBT test were determined. The stimulation index of the NBT test (NBTst-NBTsp) was calculated. The mitochondrial membrane potential was determined using a BD FACS Calibur cytometer (USA) (BD Pharmigen, USA). PN in children with chronic heart disease with progressive PF was significantly reduced in comparison with patients in the comparison group and with the control group. The PHAN in children with CKD in both groups was within the standard values, however, it was lower than in the control group. The activity of the spontaneous HBT test in children of the main group was 1.7 times higher than in children in the comparison group and 3 times higher than in children from the control group. However, the stimulation index in the main group was significantly lower than in the control group. An increase in cells with a reduced membrane potential of granulocyte mitochondria was revealed in children of the main group compared with the control group. Children with CKD with the progression of fibrosis processes develop changes in the functional and metabolic activity of peripheral blood neutrophils typical for an inflammatory reaction, characterized by an increase in oxygen-dependent and a decrease in phagocytic cell activity.