Impaired antibody responses in the hyperimmunoglobulin E syndrome

Area of Science:

• Immunology
• Infectious Diseases
• Genetics

Background:

• Hyper-IgE (HIE) syndrome is characterized by recurrent bacterial infections, particularly with Staphylococcus aureus and encapsulated organisms.
• The underlying immunological defects contributing to HIE syndrome's susceptibility to infection require further elucidation.

Purpose of the Study:

• To investigate the role of impaired antibody responses to polysaccharide antigens in patients with HIE syndrome.
• To compare antibody levels and responses in HIE patients with control groups.

Main Methods:

• Measurement of serum antibody levels to Staphylococcus aureus teichoic acid and Haemophilus influenzae type b capsular polysaccharide.
• Assessment of antibody response after immunization with Haemophilus influenzae type b vaccine.
• Analysis of IgG subclass levels, including IgG2 deficiency.

Main Results:

• HIE patients exhibited significantly lower antibody levels to teichoic acid compared to atopic dermatitis patients with S. aureus infections.
• Antibody response to Haemophilus influenzae type b polysaccharide vaccine was significantly impaired in HIE patients.
• Most HIE patients displayed IgG2 subclass deficiency, unlike atopic dermatitis patients.
• Impaired antibody responses were also observed for non-polysaccharide antigens, such as antitetanus toxoid.

Conclusions:

• Patients with HIE syndrome demonstrate defective antigen-specific antibody production, particularly against polysaccharide antigens.
• IgG2 subclass deficiency is common in HIE syndrome and may contribute to impaired antibody responses.
• These immunological deficits likely play a significant role in the increased susceptibility to infections observed in HIE syndrome.