Evaluation of Cross-Reactivity between <i>Holoptelea integrifolia</i> and <i>Parietaria judaica</i>

Abstract

Background:Holoptelea integrifolia and Parietaria judaica belong to the family Urticaceae, but are geographically distantly located. H. integrifolia is an important pollen allergen of India and sensitizes almost 10% of the atopic population in Delhi. P. judaica, on the other hand, is a very dominant pollen allergen of the Mediterranean region, sensitizing almost 80% of the allergic population. Since both these important pollen allergens belong to the family Urticaceae, the objective of the present study was to assess cross-reactivity between these two pollen allergens from different geographical regions. Methods: Cross-reactivity between these two pollen allergens was assessed on the basis of skin prick tests and ELISA, ELISA inhibition and immunoblot inhibition studies. Results: Out of 44 atopic Indian patients skin prick tested with H. integrifolia extract, 34% were found to be sensitized. All the patients sensitized to H. integrifolia also showed varying degrees of skin positivity to P. judaica pollen extract. ELISA and ELISA inhibition studies suggested strong cross-reactivity between H. integrifolia and P. judaica pollen. Immunoblot inhibition studies revealed that 14-, 16-, 28-, 38-, 42- and 46-kDa proteins are the cross-reactive proteins in H. integrifolia and P. judaica. However, Par j 1, the major allergen of P. judaica, is absent in H. integrifolia pollen. Conclusion:H. integrifolia and P. judaica pollens share cross-reactive as well as unique epitopes. The major allergen of P. judaica, Par j 1, seems to be absent in H. integrifolia pollen allergen.

Cross-reactivity of pollen allergens: recommendations for immunotherapy vaccines

“…The major Parietaria judaica pollen allergens, Par j 1 and Par j 2, are non-specific lipid transfer proteins (nsLTPs), and exhibit significant sequence homology [27]. Another member of Urticaeae, Holoptelea integrifolia, although not containing a Par j 1 homologue, does show immunoblot cross-inhibition with pellitory [28 ]. Asero and colleagues [29] were not able to not show cross-inhibition between profilins of pellitory, grass, or birch, whereas Asturias and associates [30 ] did report cross-reactivity with recombinant profilin Par j 3.…”

Evaluation of antimicrobial, antioxidant and wound-healing potentials of Holoptelea integrifolia

“…It is an important pollen allergen of India and sensitizes almost 10% of the atopic population in Delhi (Sharma et al, 2005). Recently, an "All India Coordinated Project on Aeroallergens and Human Health" was undertaken to discover the quantitative and qualitative prevalence of aerosols at 18 different centers in the country and found Holoptelea is one of the predominant allergen (Singh and Kumar, 2003).…”

Case series of seven cases of urticaria, angioedema, and anaphylaxis (LTP syndrome) due to foods (nuts, lentils, and citrus foods) related to tree pollen (Prosopis juliflora and Holoptelea integrifolia) sensitization

“…H. integrifolia and P. judaica belong to the family urticacea and share cross-reactive proteins of the molecular weight in the range of 14-95 kDa (14kDa cross-reactive protein in both allergens seems to be profilin). Cross-reactive proteins in H. integrifolia and P. judaica strongly reacts to Indian allergic patients, while major allergen of P. judaica, (Par j 1) is absent in H. integrifolia [6].…”