Inhalation challenge with bovine dander allergens: who needs it?

Area of Science:

• Allergy and Immunology
• Occupational Medicine
• Respiratory Medicine

Background:

• Occupational asthma is a significant concern for dairy farmers.
• Accurate diagnosis of bovine allergen-induced asthma is crucial for effective management.
• Identifying reliable tests for patient selection for specific inhalation challenges is needed.

Purpose of the Study:

• To determine the utility of various diagnostic tests in selecting patients for bovine specific inhalation challenge (bSIC).
• To evaluate the predictive value of histamine challenge, mannitol challenge, exhaled nitric oxide (NO), bovine-specific serum IgE, and skin prick tests (SPT) for bSIC response.

Main Methods:

• A prospective study was conducted at a university hospital.
• Thirty-seven dairy farmers with suspected occupational asthma underwent histamine challenge, mannitol challenge, exhaled NO measurement, bovine-specific IgE, and SPT prior to bSIC.
• Twenty-seven patients completed all procedures.

Main Results:

• Eleven patients responded to the bovine allergen inhalation challenge.
• Bovine-specific serum IgE and SPT demonstrated high sensitivity and specificity (82% and 100% for IgE; 100% and 50% for SPT).
• Only IgE-mediated sensitivity to bovine allergens significantly predicted the response to bSIC.

Conclusions:

• Skin prick tests (SPT) with bovine allergens and bovine-specific serum IgE measurements are valuable for selecting patients for bSIC.
• SPT-negative individuals should not undergo bSIC.
• High bovine-specific IgE levels in asthmatic patients may allow for diagnosis without bSIC, reducing the need for the procedure.