recently, the efficacy of anti-ige therapy has been monitored through the quantification of the sensitivity of allergen-specific basophil activation (CD63 up-regulation) as expressed by CD-sens. CD-sens is defined as the inverted value for allergen concentration giving a 50% of maximum CD63% up-regulation multiplied by 100. the higher CDsens value means an elevated basophil allergen sensitivity. moreover, CD-sens value has been suggested as a predictive factor of tolerance in food allergy.