Background: The pathophysiology of eosinophilia and hyper-IgE is not fully
elucidated yet.
Objective: To clarify the pathophysiology of a patient with remarkable eosi
nophilia and hyper IgE, we examined cytokine levels in serum, surface antig
ens of peripheral blood eosinophils and IgE production in vitro.
Results: Concentrations of tumor necrosis factor-alpha (TNF-alpha), interle
ukin3 (IL-3), interleukin-4 (IL-4), interleukin-5 (IL-5), and granulocyte/m
acrophage-colony stimulating factor (GM-CSF) in the serum were 21 pg/mL, <1
5 pg/mL, <15 pg/mL, 8 pg/mL, and <5 pg/mL pg/mL, respectively. Newly expres
sed surface antigens CD4, CD25, CD69, and HLA-DR, but not CD54, were observ
ed on peripheral blood eosinophils. Extremely high levels of IgE secretion
was found in the patient's mononuclear cells without stimuli; this was not
enhanced by IL-4 or IL-4 plus anti-CD40 monoclonal antibody stimulation. Fu
rthermore, highly purified B cells spontaneously produced large amounts of
IgE and the production was not enhanced in addition of his T cells.
Conclusion: The eosinophils were activated, and the B cells spontaneously p
roduced IgE independently of T cells or cytokines, suggesting that intrinsi
c abnormality of B cells leading to disregulated production of IgE in this
disease.