Massive polyclonal hyperimmunoglobulinemia E, eosinophilia and increased IgE-bearing lymphocytes

Area of Science:

• Immunology
• Hematology

Background:

• A patient presented with severe eosinophilia and hyperimmunoglobulin E (IgE).
• Elevated levels included peripheral blood eosinophils >18,000 cells/mm3 and serum IgE >210,000 units/ml.
• The patient exhibited increased peripheral blood lymphocytes expressing surface IgE.

Purpose of the Study:

• To investigate the characteristics of extreme eosinophilia and hyperimmunoglobulin E (IgE) in a patient.
• To determine the in vivo behavior of the patient's IgE in a non-human primate model.

Main Methods:

• Longitudinal follow-up of patient E.M. over 4 years.
• Analysis of peripheral blood eosinophil and lymphocyte counts.
• Quantification of serum IgE levels and characterization of IgE light chains (polyclonal).
• Plasma transfer (plasmsEM) to a rhesus monkey to assess eosinophilia induction.
• Determination of IgE half-life in the rhesus monkey.

Main Results:

• Patient E.M. exhibited marked eosinophilia and polyclonal hyperimmunoglobulin E (IgE).
• Transfer of patient plasma to a rhesus monkey did not induce eosinophilia.
• The half-life of the patient's IgE in the rhesus monkey was 2.2 days, comparable to human myeloma IgE.
• No significant morbidity was observed, apart from mild pruritus; no atopic, parasitic, immune deficiency, or neoplastic diseases were identified.

Conclusions:

• The patient's condition represents a unique presentation of marked eosinophilia and hyperimmunoglobulin E (IgE) without significant associated morbidity.
• The patient's IgE appears functionally distinct, as evidenced by the lack of induced eosinophilia in a rhesus monkey model.
• Further research is needed to elucidate the specific mechanisms underlying this distinct immune profile.