Occupational rhinitis and bronchial asthma due to artichoke (Cynara scolymus).

BACKGROUND

The artichoke is a perennial horticultural plant that belongs to the Compositae family.

OBJECTIVE

To present case studies of 2 vegetable warehouse workers who developed occupational rhinitis and bronchial asthma by sensitization to artichoke.

METHODS

Skin prick tests with common inhalants and foods were performed. Specific IgE to artichoke, Parietaria judaica pollen, and Olea europaea pollen extracts was measured by a specific IgE enzyme immunosorbent assay kit. Molecular mass of the allergens was studied by the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) immunoblotting technique. Patients underwent a nasal challenge test, and one patient provided peak expiratory flow rate (PEFR) measurements in her workplace.

RESULTS

In both patients, results of skin prick tests to artichoke were positive. Levels of specific IgE for artichoke were 0.68 kU/L in patient 1 and 2.14 kU/L in patient 2. The protein composition of the artichoke extract, studied by SDS-PAGE, showed that most bands ranged from 30 to 14 kDa. The IgE-binding bands with the serum samples of patient 1 showed apparent molecular masses of 56, 48, 38, 31, 27, 25, 16, and 15 kDa; however, the serum samples of patient 2 showed IgE bands of 21 and 19 kDa. Western blotting of artichoke extract showed a complete inhibition of IgE-binding bands when serum samples were preincubated with P. judaica pollen extract. Nasal challenge with artichoke extract triggered a peak nasal inspiratory flow decrease of 81% and 85% in patient 1 and patient 2, respectively. Finally, patient 1 recorded a PEFR decrease of up to 36% after exposure to artichoke in her workplace.

CONCLUSIONS

SDS-PAGE immunoblotting inhibition performed for the artichoke extract showed a total disappearance of the specific IgE binding bands when serum samples were previously incubated with P. judaica pollen extract, thus establishing the existence of a serologic cross-reactivity between artichoke and P. judaica pollen.