[Evaluation of Th1/Th2 lymphocyte balance and lipopolysaccharide receptor expression in asthma patients]

An increase in the number of asthma patients which has recently been observed depends on their place of residence and their occupation. This suggests that both external factors and genetic predispositions affect the development of the disease. The contact with bacterial lypopolysaccharide (LPS) may suppress the development of asthma among rural inhabitants. The mechanism of LPS effect most probably consists in the activation of macrophages and granulocytes by TLR4 and CD14 receptors for the production of cytokines, which affect Th1/Th2 balance. The objective of the study was the evaluation of CD14 and TLR4 expression on mononuclear cells and the analysis of Th1/Th2 balance in peripheral blood among asthma patients.

The study group covered 22 patients with bronchial asthma (mean age 45 +/- 15), and was conducted by the method of flow cytometry with the use of fluorochrome-labelled monoclonal antibodies. CD14 and TLR expression was assessed in peripheral blood monocytes. Th1/Th2 balance was determined by the measurement of intracellular IL-2, IFN-gamma, IL-4 and IL-10 expression in T-helper cells after culture with the stimulation of cytokine production.

A negative correlation was noted between TLR4 expression and the percentage of Th2 lymphocytes, while a positive correlation was observed between expression of TLR4 and percentage of Th1 cells. No relationship was found between CD14 expression on monocytes and the percentage of Th1 and Th2 lymphocytes.

An increased percentage of lymphocytes with TLR4 expression is associated with the change in Th1/Th2 balance in favour of Th1 lymphocytes in asthma patients.