Alternaria IgG precipitins and adverse reactions

Area of Science:

• Immunology
• Allergy and Clinical Immunology

Background:

• Late reactions (fever, malaise, swelling) can occur 4-6 hours after Alternaria extract immunotherapy.
• Patients experiencing these reactions often show serum IgG precipitins and high leukocyte histamine release sensitivity to Alternaria.

Purpose of the Study:

• To investigate the role of serum IgG precipitins to Alternaria in late immunotherapy reactions.
• To determine if the presence of precipitins contraindicates Alternaria immunotherapy.

Main Methods:

• Observational study comparing precipitin frequency in Alternaria immunotherapy patients versus controls.
• Prospective monitoring of precipitin development and late reactions in Alternaria-sensitive individuals during immunotherapy.

Main Results:

• Serum IgG precipitins to Alternaria were significantly more frequent (3x) in patients receiving Alternaria immunotherapy compared to controls.
• In a prospective study, 11 of 23 Alternaria-sensitive individuals developed precipitins during therapy.
• Only one individual experienced a late reaction, suggesting precipitins are not the primary cause.

Conclusions:

• Alternaria-specific IgG precipitins are common in patients undergoing immunotherapy.
• The presence of these precipitins does not appear to be the cause of observed late reactions.
• Finding precipitins should not contraindicate Alternaria immunotherapy.