Evidence for eosinophil activation in cow's milk allergy

Area of Science:

• Immunology
• Allergology
• Pediatrics

Background:

• Cow's milk allergy (CMA) presents with diverse clinical manifestations.
• Understanding the underlying immunopathogenesis is crucial for targeted therapies.
• Eosinophils are implicated in allergic inflammation but their specific role in CMA subtypes requires clarification.

Purpose of the Study:

• To investigate the role of eosinophil activation in different clinical presentations of cow's milk allergy.
• To compare eosinophil involvement in cutaneous versus gastrointestinal CMA.
• To identify pathogenetic mechanisms contributing to CMA manifestations.

Main Methods:

• Study included 28 patients with challenge-proven CMA (17 cutaneous, 11 gastrointestinal) and 80 controls.
• Serum eosinophil cationic protein (ECP) levels were measured before, during, and after an oral cow's milk challenge.
• ECP levels in CMA patients were compared to age-matched non-allergic controls.

Main Results:

• Serum ECP levels significantly increased during the oral cow's milk challenge in CMA patients with cutaneous manifestations.
• The increase in ECP levels was transient, returning to baseline levels one week post-challenge.
• No significant increase in ECP was observed in CMA patients with gastrointestinal symptoms during the challenge.

Conclusions:

• Eosinophil degranulation is a significant immunologic mechanism in cutaneously manifested cow's milk allergy.
• Eosinophil activation appears specific to the skin-related allergic response in CMA.
• These findings aid in differentiating pathogenetic pathways in various CMA clinical presentations.