CLINICALLY RELEVANT CROSS-REACTIVITY BETWEEN LATEX AND PASSION FRUIT

Abstract

A 36-year-old woman reported that she had experienced generalized urticaria, oropharyngeal pruritus, tongue swelling, dysphagia, dysphonia, cough, rhinorrhea, sneezing, lacrimation, and ocular itching immediately after drinking a 330-mL can of mango and passion fruit juice. A year before the reaction, she had experienced an episode of oropharyngeal pruritus minutes after eating a chestnut. She reported local pruritus and erythema whenever she used latex gloves during the last 5 years. The patient eats avocado and banana with no adverse symptoms. After obtaining informed consent, we conducted skin prick testing with passion fruit–mango juice, passion fruit, mango, and chestnut by the prick-prick method. Then, 9- and 22-mm wheals were observed in the patient after testing with passion fruit–mango juice and passion fruit, respectively; skin test results were negative with mango and chestnut. The skin prick test result was positive with a latex extract (wheal diameter, 26 mm). Specific IgE levels (UniCAP assay; Phadia, Uppsala, Sweden) to passion fruit, chestnut, latex, and rHev b 6.02 (hevein) were 2.17, 0.72, 10.50, and 14.30 kUA/L, respectively. No specific IgE was detected with mango extract or rHev b 1, 3, 5, 8, 9, and 11. By UniCAP-inhibition experiments, the patient’s IgE antibody to passion fruit was completely inhibited by latex extract (0.1 mg/mL), but IgE binding to latex and rHev b 6.02, inhibited with passion fruit (1 mg/mL), yielded a partial inhibition (58% and 63%, respectively). Sodium dodecyl sulfate–polyacrylamide gel electrophoresis/immunoblotting studies of passion fruit extract showed IgE binding components of 16 to 54 kDa. A complete dose-dependent inhibition of passion fruit was observed after preincubation with latex extract (Fig 1). A double-blind, placebo-controlled food challenge was performed with chestnut. Increasing doses of a liquid vehicle (custard, milk, coffee, sugar, and wheat germ) containing (verum) or not (placebo) ground chestnut were administered on separate days. A cumulative dose of 5.4 g of chestnut elicited a clinical response. The result of an open food provocation with fresh mango was negative. Symptoms induced by the offending juice precluded further challenges with passion fruit. Cross-reacting IgE antibodies recognizing latex and passion fruit allergens were first demonstrated by radioallergosorbent inhibition tests. 1 In addition, putative class 1 chitinases have been reported to be relevant cross-reactive components in foods associated with the latexfruit syndrome. 2 Our investigation confirms the cross-reactivity between passion fruit and latex in a patient with IgE (to hevein) from latex and its clinical relevance. Therefore, it could be important to evaluate the risk of reaction to passion fruit in latex-allergic patients because exposure to this exotic fruit, even as a component of soft drinks, could not be exceptional and might be a risk for allergic reactions.