Spontaneous B-cell IgE production in a patient with remarkable eosinophilia and hyper IgE

Background The pathophysiology of eosinophilia and hyper-IgE is not fully elucidated yet. Objective To clarify the pathophysiology of a patient with remarkable eosinophilia and hyper IgE, we examined cytokine levels in serum, surface antigens of peripheral blood eosinophils and IgE production in vitro. Results Concentrations of tumor necrosis factor-α (TNF-α), interleukin-3 (IL-3), interleukin-4 (IL-4), interleukin-5 (IL-5), and granulocyte/macrophage-colony stimulating factor (GM-CSF) in the serum were 21 pg/mL, Conclusion The eosinophils were activated, and the B cells spontaneously produced IgE independently of T cells or cytokines, suggesting that intrinsic abnormality of B cells leading to disregulated production of IgE in this disease.