Profilins are ubiquitous proteins, present in all eukaryotic cells and identified as allergens in pollen, latex and plant foods.
Profilins have a highly conserved structure that may be the reason for cross-reactivity. IgE antibodies against plant profilins react to wide varity of allergens, hence the designation of prolifins as pan-allergens.
Primary sensitization to profilin arises from pollen sensitization with later development of cross-reactive IgE antibodies against plant food (and possibly latex) profilins.
Cross-reactivity in Pollen-Food Allergy Syndrome (PFAS) or Oral Allergy Syndrome (OAS) (click to enlarge the image).
IgE cross-reactivity among profilins is associated with multiple pollen sensitization and with various pollen-food syndromes (oral allergy syndrome).
In respiratory allergy, sensitization to pollen to which the patient has virtually no environmental exposure has been identified as a manifestation of profilin sensitization.
As a food allergen, profilin usually elicits mild reactions, such as oral allergy syndrome. However, 1-10% of patients with oral allergy syndrome may develop anaphylactic reactions, and many allergists started prescribing EpiPens to the patients with this condition.
Prolifins are especially important in allergy to some fruits, such as melon, watermelon, banana, tomato, citrus fruit and persimmon.
Natural and recombinant profilins are available for in vitro and in vivo allergy tests in some countries.
Although the role of profilins in triggering allergic symptoms is still controversial, they are relevant allergens. As a pan-allergen, profilin is associated with multiple pollen sensitization and pollen-food-latex syndromes that allergists, and other physicians, must to be aware of.
Profilins: Mimickers of Allergy or Relevant Allergens? Santos A, Van Ree R. Int Arch Allergy Immunol. 2011 Feb 2;155(3):191-204.