Abstract
Polcalcins are highly cross-reactive calcium-binding allergen components specifically expressed in pollen from trees, grasses and weeds. The grass allergen component rPhl p 7, a recombinant non-glycosylated calcium-binding protein of 2-EF-hand type, is the most cross-reactive polcalcin and may be used as a polcalcin biomarker of IgE-mediated hypersensitivity. Polcalcin sensitization, which appears to be linked to geographical factors, level and time of pollen exposure, has to be assessed in allergic rhinitis patients with multiple pollen sensitizations and may be useful for a better targeted prescription of allergen immunotherapy.