Bactericidal capacity of oral neutrophils as a marker for clinical course of inflammatory ­respiratory diseases in children

Abstract

Aim. To study the number of neutrophils in the oral cavity, their bactericidal potential, to assess as an indicator for predicting the course of recurrent bronchitis (J40) and community-acquired focal pneumonia in children. Methods. 87 children between 5 and 10 years old, including 52 children with recurrent bronchitis and 35 with focal community-acquired pneumonia were observed. The control group consisted of 37 conditionally healthy children of a similar age. Viral antigens were studied by chemiluminescence immunoassay. Oral neutrophil counts and functional activity were determined. Antibacterial antibodies were measured by an enzyme-linked immunosorbent assay (ELISA). Results. 70.11% of patients had a viral antigen, and 57.47% had immunoglobulins M and G against bacterial pathogens. Oral neutrophil counts increased in the main group compared to the control group: up to 163.8±26.5 cells (p <0.001) in recurrent bronchitis, to 110.9±25.5 (p <0.05) in community-acquired pneumonia. By the recovery period, the number of oral neutrophils counts decreased in recurrent bronchitis (1.7 times higher compared to the control group, p <0.01) and remained practically unchanged in community-acquired pneumonia (115.0±26.9, p <0.05). Myeloperoxidase level had opposite changes for the groups compared to the control group: with recurrent bronchitis, it was 1.61±0.09 to the level in the control group (p <0.05), with community-acquired pneumonia — 0.73±0.09 to the level in the control group (p <0.001). The level of lysosomal cationic proteins decreased to 0.77±0.09 to the level in the control group (p <0.05) in recurrent bronchitis, and to 0.80±0.09 (p <0.05) in pneumonia. Conclusion. In inflammation of the respiratory tract, neutrophil migration to the oral cavity, as well as myelope­roxidase level, increases, indicators of spontaneous luminol-dependent chemiluminescence are activated, and a deficiency of lysosomal cationic proteins occurs; this prevents the penetration of the pathogen into the lower respiratory tract.