Identification of cross-reactive and genuine Parietaria judaica pollen allergens.
BACKGROUND
The weed Parietaria judaica is one of the most important pollen allergen sources in the Mediterranean area.


OBJECTIVE
We sought to identify P judaica pollen allergen, which might be used to serologically distinguish genuine Parietaria sensitization and cross-reactivity to allergens from other weed species (eg, mugwort and ragweed).


METHODS
The allergen profile of P judaica IgE-reactive sera from weed pollen-sensitized allergic individuals from the Mediterranean region (n = 36) with high Parietaria pollen exposure and from weed pollen-allergic patients with little or no Parietaria exposure (Austria, n = 42; Scandinavia, n = 8; United States, n = 19) was established by CAP FEIA measurements and by IgE immunoblot inhibition experiments with recombinant allergens.


RESULTS
The majority (83%) of the Mediterranean weed pollen-allergic patients mounted high IgE antibody levels (mean specific IgE, 20.89 kUA/L) against recombinant (r) Par j 2, whereas only 7% of the non-Mediterranean weed-allergic patients showed low IgE reactivity to rPar j 2 (mean specific IgE, 1.03 kUA/L). The cytoskeletal protein profilin and a 2-EF-hand calcium-binding allergen were identified as cross-reactive Parietaria allergens, which were recognized preferentially by Parietaria -positive, non-Mediterranean weed pollen-allergic patients.


CONCLUSIONS
rPar j 2 might be used as a diagnostic marker allergen to identify weed pollen-allergic patients who are genuinely sensitized against Parietaria pollen and thus would be particularly suited for specific immunotherapy with Parietaria pollen extract.
Stumvoll
Sabine
S
Department of Pathophysiology, AKH, University of Vienna, Vienna, Austria.
Westritschnig
Kerstin
K
Lidholm
Jonas
J
Spitzauer
Susanne
S
Colombo
Paolo
P
Duro
Giovanni
G
Kraft
Dietrich
D
Geraci
Domenico
D
Valenta
Rudolf
R
D000485:Allergens / Q000276:immunology*; D052179:Antigens, Plant; D003429:Cross Reactions; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007167:Immunotherapy; D032403:Parietaria / Q000276:immunology*; D010936:Plant Extracts / Q000276:immunology; D011058:Pollen / Q000276:immunology*
D000485:Allergens; D052179:Antigens, Plant; C103299:Par j 2.0101; D010936:Plant Extracts; D007073:Immunoglobulin E