Grape is a food which may result in allergy symptoms in sensitised individuals.

Grape Allergy Test: Allergen Exposure

Grapes are one of the oldest cultivated fruits, having been grown by humans for thousands of years. The plant grows in temperate and subtropical climates, especially around the Mediterranean, and is farmed for its fruit which is consumed either directly or as juice. Grape juice is widely used in the production of wine, with France, Italy, and Spain among the major producers. In recent years, grapes have been produced in greater numbers in South America, Africa and Asia.

The composition of the pulp of the ripe fruit varies widely, depending on the variety of vine, the climate, the physicochemical characteristics of the soil, and the agricultural methods employed

Grape Allergy Test: Allergen Description

While a number of allergenic proteins have been isolated, few of these have been characterised. Assessing grape allergens is made more difficult by the low protein and high tannin and pectin concentrations of grape.

Grape allergy may be specific to a certain grape variety while there is tolerance to others, and some patients may be allergic to grape but not wine, whereas others might not tolerate grape, wine or raisins.

Allergens which have been characterised include among them a lipid transfer protein, a profilin, a chitinase-like protein, and a thaumatin-like protein. The lipid transfer protein is a major allergen and may sensitise between 70% and 100% of grape-allergic individuals. Severe grape allergy has been linked to lipid transfer protein sensitisation.

Grape Allergy Test: Potential Cross-Reactivity

Cross-reactivity between grapes and Rosaceae fruits can be expected.

Grape contains a thaumatin, a protein analogous to the cherry thaumatin-like allergen, which may result in cross-reactivity with other foods containing this panallergen. However, the protein is a minor allergen in grape.

Grape also contains a lipid transfer protein, which may result in cross-reactivity with other lipid transfer protein-containing foods such as peach and cherry. Lipid transfer protein is a widely cross-reacting plant panallergen found in Rosaceae, tree nuts, peanut, beer, maize, mustard, asparagus, grape, mulberry, cabbage, date, orange, fig, kiwi, lupin, fennel, celery, tomato, eggplant, lettuce, chestnut and pineapple.

Cross-reactivity has also been reported to occur among apricot, avocado, banana, cherry, chestnut, grape, kiwi, papaya, passion fruit, peach and pineapple, as well as between grape and peach, and between grape and cherry.

Grape Allergy Test: Clinical Experience

Grape has been reported to cause oral allergy syndrome, generalised urticaria, asthma, atopic dermatitis, angioedema, gastro-intestinal symptoms, hypotension, rhinitis, and exercised-induced asthma and anaphylaxis.

Adverse reactions to wine may be caused by allergic reactions to grape, but may also be the result of the presence of other components in the wine such as sulphites, histamine or alcohol. The composition of red wines is affected by both the active wine-making process and aging.

Other reactions

Some patients complain of abdominal distension and excessive flatus after ingesting grape. This has been attributed to the presence of fructose in grape.

After wine consumption, symptoms such as flush, rhinitis, asthma, and migraine are not rare. Such symptoms could be caused by an immediate-type reaction to grape or moulds, as well as by intolerance reactions to histamine and sulphite.

Vine pollen could be the cause of rhinoconjunctivitis and asthma in allergic individuals living in areas with a high density of vineyards.