Reduced IL-2 but elevated IL-4, IL-6, and IgE serum levels in patients with cerebral infarction during the acute stage

Cytokines in the central nervous system (CNS) may play an important role in functioning as intercellular signals that orchestrate the response to inju ry. Whether this is a cause or result of the brain disease process is uncer tain. We investigated IFN-gamma, IL-2, IL-4, IL-6, and IgE in the sera of 3 8 patients with cerebral infarction during the acute stage and 10 normal co ntrols using an originally devised sensitive sandwich enzyme-linked immunos orbent assay (ELISA). We found that serum levels of IL-2 derived from T hel per 1 (Th1) cells were slightly reduced in patients with cerebral infarctio n, whereas serum levels of IL-4 and IL-6 derived from Th2 cells were elevat ed significantly. IL-4 induces synthesis of IgE in human B cells. Endogenou s IL-6 plays an obligatory role in IL-4-dependent human IgE synthesis. We o bserved that serum IgE levels were elevated significantly in patients with cerebral infarction. However, serum IFN-gamma levels were not elevated sign ificantly in cerebral infarction patients. These findings suggest that elev ated IL-4, IL-6, and IgE levels in the human serum may be an important fact or in cerebral infarction during the acute stage. Decrease of IL-2 levels i n the serum of patients with cerebral infarction may be a regulatory mechan ism.