State of Local Immunity in Children with Frequent Respiratory Infections

Introduction. Today the study of the features of local immunity of oropharyngeal mucosa in children who are often suffer from acute respiratory diseases (sickly children — SC), is urgent. Objective. To determine β-defensins content in oropharyngeal secretion (OPS) in SC on the background of chronic foci of infection of upper respiratory tract. Methods. We examined 30 SC with chronic compensated tonsillitis aged from 4 to 12 years. In all children we investigated β-defensins content in OPS in non-acute period. The children were divided into two groups according to age: Ch1 — 4–7 years (n = 15), Ch2 — 8–12 years (n = 15). During investigation we used clinical, immunological, laboratory, bacteriological and statistical methods. Results. The content of β-defensin in OPS of SC aged 4–7 years was significantly lower than in SC aged 8–12 years, and is respectively 0.85 (0.12–2.25) and 4.8 (0.26–9.88 ). Defensin levels in 4–7-year-old children is below the minimum standard at which the β-defensins (HBD1-3) can show antimicrobial activity. Clinically, group of SC aged 4–7 years is characterized by a greater incidence of ARVI and exacerbations of chronic tonsillitis, 73.3 % (11) of 4–7-year-old children had bacteriologically confirmed intestinal dysbiosis, older children (8–12 years) — 40% (6). According to the bacteriological examination of smears from the mucous oropharynx, St.aureus was detected in 60 % (9) of children aged 4–7 years and 46.7 % (7) of children aged 8–12 years. Among these children lowest levels of defensins were registered: Ch1 — 0.46 (0.12–0.59), Ch2 — 2.61 (0.26–5.94). Conclusions. It is established that in SC with compensated chronic tonsillitis the content of β-defensins in oropharyngeal secretions is low, especially in the younger age group (4–7 years). The lowest rates were found in children, in oropharyngeal swabs of which we have detected Staphylococcus aureus