Analysis of the allergenic profile of patients hypersensitive to pollen pan-allergens living in two distinct areas of Northern Italy

D. Villalta, R. Asero

Background: The allergenic profile of patients hypersensitive to pollen pan-allergens, profilin and polcalcin, has received little attention so far. Objective: To detect whether hypersensitivity to profilin and polcalcin follows sensitization to specific allergen sources or represents a primary phenomenon, and to examine the sensitization profiles of patients hypersensitive to pollen pan-allergens. Methods: IgE reactivity to markers of primary sensitisation to different pollen species including grass, mugwort, ragweed, pellitory, birch, olive, and cypress was detected in sera from 106 pollen-allergic subjects, 86 sensitised to profilin and 29 to polcalcin living in two distinct areas of Northern Italy. Results: In profilin hypersensitive patients the primary sensitizer was detected in 24/86 (28%) cases: grass (n= 15), ragweed (n=7), and birch (n=2). In 62 (72%) cases the primary sensitizing pollen was not detectable. In the polcalcin group the primary sensitizing pollen was detected in 8/29 (28%) cases: grass (n=6), ragweed and pellitory (1 each). All ragweed-allergic subjects were from the Milan area. In the 9 patients hypersensitive to both panallergens the primary sensitizing source could be identified in 2 (23%) cases (grass in both cases). Conclusion: A putative primary sensitizer to pollen pan-allergens can be detected only in ¼ of cases, as most patients show IgE specific for > 1 pollen species. In these patients the prevalence of the primary sensitizer parallels the prevalence of clinical allergy to the different pollen sources in that specific geographic area. Most pollen sources are probably able to cause sensitization to cross-reacting pollen pan-allergens.

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