Garden Chervil ( Anthriscus Cerefolium), a Novel Food Allergen

There are no conflicts of interest for this topic. No case of allergy to garden chervil (Anthriscus cerefolium L, Apiaceae family), has been studied or published so far. Case report: A 43-year-old man ate home-made chervil soup on a regular basis from a decade. In 2012, he began to present diarrhea immediately after eating chervil soup. He also mentioned oral allergy syndrome with fresh apple, cherry, hazelnut, walnut, and fresh parsley. Symptoms worsened progressively with chervil (throat itching, uvula swelling, voice changes and diarrhea). An allergological workup was performed in 2018. Skin prick-tests were positive for mites, cat, horse; grass, birch and hazel pollens; fresh apple (weal/flare: 5/18 mm); raw and cooked chervil (each w/f: 10/25 mm); histamine 6/18 mm; negative for mugwort. Total IgE were 138 kU/l; sIgE (CAP ThermoFisher, kU/l): positive for Dactylis glomerata 2.53, birch pollen 8.36, rBet v1 7.03; <0.10 for rBet v2, rPru p3, mugwort, parsley, celery and rApi g1. A specific A. cerefolium ImmunoCAP was developed by the Special Allergen Service at Thermo Fisher (Uppsala, Sweden) and gave a positive result of 2.39 kUA/l with patient's serum. Allergens in raw and cooked (10 min-100°C) chervil extracts were studied by SDS-PAGE followed by immunoblotting (ALK Allergen Research, France). Protein content was 1.7 (raw) and 1.2 (cooked) mg/ml (Bradford method). A binding of patient's serum sIgE was observed around 14 kDa with raw chervil extract and remained detectable (to a lesser extend) with cooked chervil extract; this is compatible with an LTP, a 10-14 kDa thermostable allergen. The Rubisco was detected in raw chervil extract at 55 kDa by an anti-heavy chain rubisco antibody but not by patient's IgE. Rubisco was no more detectable in cooked chervil extract (probably denatured). This is the first published case of IgE-dependent allergy to garden chervil. The patient's sIgE are monospecific to a 14 kDa thermostable allergen, which could be a chervil LTP.