Melon sensitivity shares allergens with Plantago and grass pollens

Abstract

Possible associations between allergy to pollen and that to food allergens were studied in 262 patients sensitized to pollen. Forty-four patients (16.7%) showed some allergic symptoms after testing with fruits and vegetables, melon being the food most frequently involved (24 patients), followed by sunflower seed (12 patients). Skin testing was done by the prick method with natural fruit or vegetable, and also with commercial food extracts. We found in our region that the distribution of sensitivity to pollens in the group of patients with allergy to fruits or vegetables does not coincide with the prevalence in pollen-allergic subjects in general, since in the first group--subjects allergic to food--there was a major prevalence of allergy to Plantago (P < 0.01). In particular, in the group of subjects allergic to melon, the prevalence of sensitivity to grass and especially to Plantago was larger than in pollen-allergic subjects in general (P < 0.05 and P < 0.001, respectively). The use of fresh food produced better results than commercial extracts. A positive skin test to fresh melon closely correlated with positive CAP results. CAP inhibition experiments were carried out, and we found that Dactylis and Plantago extracts inhibited the binding of the melon-positive pool to solid-phase melon. The results suggest the existence of common antigenic epitopes in melon and Plantago pollen, and in melon and grass pollen.

Allergenic reactivity of the melon profilin Cuc m 2 and its identification as major allergen

“…Several studies on melon allergy were carried out with different series of patients since its first description in 1970 [3]. Melon allergy is usually associated with hypersensitivity to pollens and other plant foods, OAS being its most common clinical manifestation [1, 2, 4–8]. In fact, only a low proportion of allergic subjects to melon show monosensitization or severe systemic reactions.…”

“…Subsequently, several works have confirmed the link between hypersensitivity to melon and allergy to different pollens, even in ragweed‐free areas [4]. Oral allergy syndrome (OAS) is recognized as the most common clinical manifestation of melon allergy [1, 2, 5–7]. Moreover, cross‐reactions of melon with other fruits [1, 4, 7, 8] and with latex [9] have been also reported.…”

“…Oral allergy syndrome (OAS) is recognized as the most common clinical manifestation of melon allergy [1, 2, 5–7]. Moreover, cross‐reactions of melon with other fruits [1, 4, 7, 8] and with latex [9] have been also reported. The existence of melon allergens potentially associated with OAS and with a wide spectrum of cross‐reactivity could explain the main characteristics of allergy to this fruit.…”

Identification of Cucumisin (Cuc m 1), a subtilisin‐like endopeptidase, as the major allergen of melon fruit

“…4), such as soybean, tomato, latex, rice, barley, alnus glutinosa, etc., that have structural homology to cucumisin (cucumisin‐like proteases) suggests its widespread and ubiquitous occurrence in plants. Additionally, to the best of our knowledge several authors have found an association between allergy to melon and latex [35] or melon and tomato [36], but the protein responsible for such cross‐reacitvity has not been evaluated, and it could be linked to cross‐reactivity to cucumisin‐like proteases from unrelated vegetables. Carbohydrate cross‐reactive determinant (CCD) should be bear in mind on evaluating this possibility.…”

Sequence homology: A poor predictive value for profilins cross-reactivity

“…Several studies addressing the cross reactivity of IgE antibodies to conservative plant allergens have shown that profilins account for some of the fruit-fruit [5], fruit-plant pollen [6], and latex-food syndromes [7]. For example, it seems profilins are involved in the celery-mugwort-spice syndrome and cross-reactivity between ragweed pollen and cucurbitaceous family [8,9]. …”