Lymphocyte membrane antigen expression and intracellular cytokine patterns in an asymptomatic patient with persistently high serum levels of IgE.
Patients completely asymptomatic with extremely high levels of IgE have rarely been reported. One such case, in which the immunophenotype pattern of lymphocyte subsets and their cytokine profile were investigated, is described here. To assess whether the cytokine production was consistent with a T helper 2-type immune response, as suggested by theories regarding the functional polarization of helper and cytotoxic T cells in hyper-IgE conditions. An asymptomatic 79-year-old man presented with persistent high levels of serum IgE and sporadic hypereosinophilia without any evidence of an underlying pathologic condition. We investigated the immunophenotype of circulating lymphocytes, the expression/release of CD30 (a member of the tumor necrosis factor receptor family preferentially associated with T helper 2-type immune responses) and the intracellular patterns of interferon-gamma (IFN-gamma), Interleukin-2 (IL-2), IL-4, IL-5, and IL-10 production by T cell subsets, as evaluated by single-cell flow-cytometric analysis. The majority of lymphocytes displayed the membrane immunophenotype of NK cells. Both CD4+ and CD8+ T cells were reduced and expressed the "memory" (CD4+/CD45RO+) and the "naive" (CD8+/CD45RA+) phenotypes, respectively. Among CD4+ T cells, CD30 expression was increased in the resting condition and was further inducible following stimulation with mitogenic anti-CD3. Interleukin-4, IL-2, and IL-10 production by CD4+ T cells was increased, whereas IFN-gamma was reduced as compared with normals. The data suggest that a polarization of CD4+ T cells towards a T helper 0/2-type cytokine pattern occurred in this patient in spite of CD4+ cell reduction and NK cell expansion.