D2.290 - Allergens involved in a case report of anaphylaxis to ginger (Zingiber officinale), a very rare but severe allergy
Case report
Background: A 57-year-old woman presented symptoms of anaphylaxis with hypercritical tryptase level (12.5 vs 6.38 µg/ml), after consumption of a Bissap drink containing hibiscus flower, vanilla sugar and ginger. After laryngeal discomfort, chills and sweating, sensations of dyspnea, cough, noisy breathing and urticaria on the arms and trunk, tachycardia and hypertension occurred in the emergency department. The prick-to-prick test with freshly crushed ginger yielded a positive result. Skin prick tests confirmed sensitization to ginger, further supported by specific IgE detection (ImmunoCAP f270), with no evidence of other sensitizations. Allergens involved in this ginger case report allergy were investigated using an allergomic analysis (IgE immunoproteomic).
Method: Proteins from ginger root extract were separated by 2-dimensional gel electrophoresis and blotted on nitro cellulose membrane for western blot experiments. IgE immuno-reactivity was tested using the patient serum and located allergens were identified by mass spectrometry analysis followed by data bank queries.
Results: The relative molecular masses (Mr) of the extracted proteins from ginger root ranged from 14 to 70kDa with acidic isoelectric points (pI) between 3.5 to 5.0. The patient's IgE bound to two different zones. Zone #1was mainly at Mr 14kDa with pI 3.4 to 3.9 and zone #2 corresponded to a poorly resolved area between Mr 43 to 60kDa with pI 3.5 to 3.7. Mass spectrometry analysis followed by queries in a ginger data base extracted from Uniprot identified in zone #1 (14kDa) a bulb-type lectin domain-containing protein in multiple isoforms and in zone #2 (43-60kDa) two candidates, a glutaredoxin-dependent peroxiredoxin and a cystein protease.
Conclusion: Ginger allergy is very rare but can be severe as described in this case report. Until now, no allergen was reported in the IUIS/WHO database for ginger root (Zingiber officinale). However, a basic endochitinase of 35 kDa and a cysteine protease of 30-32 kDa have been characterized (1, 2). We confirm in our allergomic study the cysteine protease as a ginger allergen and unravel a new one, a bulb-type lectin domain-containing protein. Epidemiologic studies of ginger allergy remain to be performed to evaluate the prevalence of sensitization to these allergens.
References:
1 - Hayashi et al.. J Dermatol. 2019;46(2):e56-e5
2 - Gehlhaar et al.. Ann Allergy Asthma Immunol. 2018;121(5):624-625.
