The Th2 cells produce IL-5 (the eosinophilic factor), facilitating the production of immunoglobulin by B cells, including IgE (Чернушенко Е.Ф. и соавт., 2009). IL-5 also stimulates differentiation of eosinophil activation, improves their viability. IL-5 promotes the eosinophilia in helminthiasis, induces the ejection of basic protein by eosinophils, which has a damaging effect on the helminths. The purpose of research is to study the correlation of IL-5, eosinophilia and increased content of IgE in patients with tuberculosis in combination with toxocariasis. The study included 52 patients with pathology of the respiratory system (a combination of pulmonary tuberculosis and toxocariasis) of different ages and sex. The content of eosinophils was determined in all the patients; the content of IgE (UBI Magiwel company – USA) and of IL-5 (company Vector- Best) was determined by ELISA. Patients received the antituberculosis and immune corrective treatment with silymarin. The contents of eosinophils, IgE and IL-5 was significantly higher in patients with a combination of pulmonary tuberculosis and toxocariasis than in healthy persons (p<0,001 in all cases), showing the Th-2 expression depending of the type of response and data of the patients (see. Table). Table. The contents of eosinophils, IgE and IL-5 in patients with tuberculosis in combination with toxocariasis, comparing with healthy individuals. The considerable correlation (r = 0,64) was established between the content of eosinophils and IgE, whish confirms the data of other authors who assumed that the number of eosinophils increases in almost all reactions caused by IgE and the eosinophils are regulators of inflammation by inactivating effect of biologically active amines in allergic immediate type reactions (Бережная Н.М., и соавт., 1986) . The strong correlation (r = 0,77) was established between the content of eosinophils and IL-5, corresponding to other research results, according to which, in the infected mice with toxocara was observed an increased pulmonary capillary permeability, the inflammatory infiltration with predominant content of eosinophils, which determine the reactivity of trachea and dependent on IL-5 content (Токсокарuоз, 2004). The IgE and IL-5 are markers of allergic inflammation and there was also established a considerable correlation between them (r = 0,53). Thus, a strong correlation was established between eosinophils and IL-5 (r = 0,77), a considerable correlation- between eosinophils and IgE (r = 0,64) and between IgE and IL-5 (r = 0,53 ), which confirms the strong correlation and interaction of the studied parameters in pulmonary tuberculosis complicated with toxocariasis.