Methods: 31 children with acute episode of wheezing were included in this study (24 male, 7 female) aged from 1 to 5 years, admitted in Vladimir Children Clinical Hospital. These children were the main group. Control group included 6 children with no signs of chronic and acute inflammatory diseases. Examination included studying clinical data, detecting in blood serum subpopulations of lymphocytes, expression of Toll-like receptors (TLR-2, TLR-4) on surface of monocytes (rMFI) and number of pro-inflammatory monocytes (CD14+CD16+).
Results: We revealed high frequency of bronchial obstruction (more than 5 episodes) at 30% of children in main group. 30% of children had allergic diseases (atopic dermatitis, allergic rhinitis) in history. In group of children with recurrent wheezing revealed increased levels of pro-inflammatory monocytes (9,44±1,55% vs. 5,39±0,79%) and expression of receptors TLR-2 (8,28±0,44 conventional units vs. 6,59±0,98). In children with recurrent wheezing an inverse correlation was found between frequency of respiratory infections and level of expression of TLR-2. For frequency of acute respiratory infection up to 6 times in year the level of expression of TLR-2 was 9,11±0,31 and for children with monthly episodes of acute respiratory infections level was 7,6±0,25 (r=-0,380, p<0,05). Expression of TLR-4 was also tended to lower level in sickly children (2,2±0,16 and 2.7±0,14), however, no significant differences weren't revealed (r=-0,370, p>0.05). At the same time in patients with allergic diseases showed significant reduction in expression levels of TLR-4 compared with patients without atopy (p<0,05).
Conclusions: Increased levels of pro-inflammatory monocytes and expression of TLR-2 correspond to local inflammatory reaction and adequate immune response against background of acute respiratory illness in children with relapsing course of bronchial obstruction. Changes of TLR-2 and TLR-4 in group of children with recurrent wheezing confirm, on the one hand, risk of bronchial asthma in children with predisposition to atopy. On the other hand these changes can be the result of oppression of innate immunity in children with persistent character of bronchitis.