Is allergenic similarity predictable in respiratory allergies?

Area of Science:

• Immunology
• Genetics
• Allergology

Background:

• First-degree relatives of individuals with allergic diseases have an increased risk of developing these conditions.
• The degree of shared antigen sensitivity among related individuals with allergic diseases remains unclear.

Purpose of the Study:

• To investigate if first-degree relatives with respiratory allergies exhibit a higher likelihood of positive skin tests to the same allergen extracts compared to unrelated individuals.
• To determine the concordance of allergen sensitivity in genetically related pairs versus matched unrelated pairs.

Main Methods:

• Skin tests were performed on 264 genetically related pairs and 264 unrelated pairs using 35 common aeroallergens.
• Concordant and discordant results were calculated for each group.
• Chi-squared tests were employed to compare results between related and unrelated subjects.

Main Results:

• Significant differences in allergen sensitivity were observed for mites (Dermatophagoides pteronyssinus, Dermatophagoides farinae) and certain molds (Aspergillus mix, Rhizopus nigricans) when comparing all groups combined (p<0.05).
• Subgroup analysis revealed significant concordance in sensitivity for sibling pairs (p<0.05) but not for parent-child pairs (p>0.05).
• Aspergillus mix and Rhizopus nigricans were excluded due to a lack of dual positivity in both groups.

Conclusions:

• Parental atopy does not guarantee similar allergen sensitivity in their children.
• In cases of sibling respiratory allergies, shared antigen sensitivity is primarily linked to house dust mite allergy.