ABSTRACT
To clarify the role of immunoregulatory cytokines in pathogenesis of bronchial asthma, soluble interleukin-[2] receptor [sIL-[2R]], interleukin-4 [IL-[4]] and interferon- gamma [lFN-gama] as products of T -cell activation were estimated in bronchoalveolar lavage [BAL] fluid of asthmatic patients. Their levels were correlated with the degree of bronchial hyperreactivity [BHR] [PD[20]], sIL-[2R] and IL-[4] levels were significantly higher in asthmatics than normal controls. In extrinsic asthma their levels were significantly higher than that in intrinsic asthma. IL-[4] levels showed significant inverse correlation with PD[20] in extrinsic asthma. sIL-[2R] level showed insignificant inverse correlation with PD[20] in both extrinsic and intrinsic asthma, IL-[4] was poorly correlated with PD[20] in intrinsic asthma. There was no significant difference in concentration of IFN-gama between asthmatics and normal controls, however, it was slightly higher in normal control. The results of this study suggest that the elevated T-cell markers [sIL-[2R], IL-[4]] in BAL fluid from asthmatic patients is an indication that T-cell activation is present in asthma. The higher level of these cytokines in atopic asthma and their correlation with BHR suggest the preferential activation of the. TH[2]. The lower level of IFN-gama may suggest its role in the treatment of bronchial asthma and this may open the way for further studies