Table 3 Advantages and disadvantages of ISAC, immunoCAP, and skin prick tests

ISAC

• 30 μl of serum or plasma (capillary or venous blood)

• Manual method

• 112 allergens can be assayed in parallel

• Semi-quantitative assay

• Natural and recombinants proteins

• Less sensitive

• Less allergen needed (approximately 100, 000-fold, pg vs. μg) per assay

• More variability in the inter-assay analysis for certain allergens

• No interference from very high total IgE

• Greater coefficient of variation

• Some allergen sources are not included

• Less appropriate for monitoring sensitization

• Potential interference between IgE and other isotypes, principally IgG

ImmunoCAP

• Automatic method

• 40 μl of serum per allergen

• Quantitative assay

• One allergen per assay

• High sensitivity

• Detect low-affinity antibody that may have little to no clinical relevance

• Lower coefficient of variation

• Natural or recombinants proteins or crude extracts

• Appropriate for monitoring sensitization

Skin prick test

• High sensitivity (extract-dependent)

• Manual

• Immediate reading

• One allergen per prick

• Only crude extracts

• Not appropriate for monitoring sensitization