Fish is a staple of human nutrition and is consumed worldwide. Fish allergy is the third cause of paediatric food allergy in our environment and the sixth in adults. Parvalbumins have been reported to be the main panallergen in fish allergy. A recent case of adverse reactions to other widely consumed food (chicken) caused by cross-reactivity with fish 16-kDa parvalbumin, has been reported. A 19-year-old woman presented with oral pruritus within minutes of eating chicken for the last 6 months. She did not have symptoms with other meats nor with egg, and she did not report contact with birds. Her atopic history included urticaria and diarrhea after ingestion of fish since its introduction in the diet.
Methods:
Skin prick tests (SPTs) to commercial extracts from fishes (hake, cod, sole, sardine, trout, tuna and salmon), shellfishes (shrimp, lobster, crab, clam, mussel and squid), Anisakis simplex, meats (chicken, pork, lamb, and veal), egg white, egg yolk, ovalbumin, ovomucoid, and feather mixture were performed. Prick-by-prick test with chicken meat (raw and cooked) were also carried out. Serum specific IgE levels against fishes and chicken were measured. Protein extracts from hake (HE), and chicken (CE) were prepared, and were analyzed by SDS-PAGE immunoblotting. SDS-PAGE immunoblotting inhibition between CE and HE was also carried out.
Results:
SPT were positive to all the fishes and squid. Prick-by-prick tests were positive to raw chicken meat. Serum specific IgE against hake, cod, tuna and salmon were >100kU/L, and 2.8kU/L against chicken, out from a total IgE of 2114 UI/ml. Immunoblotting with the patient’s serum indicated IgE reactivity with an outstanding 13 kDa-protein in the HE extract, and various proteins in the CE extract, with two main ones of 16-kDa and 13-kDa. SDS-PAGE immunoblotting inhibition using CE in the solid phase showed partial inhibition of IgE binding when the patient’s serum was preincubated with HE.
Conclusions:
We present a case of chicken allergy involving a 13-kDa band as the relevant allergen in a fish-allergic patient, with demonstrated cross-reactivity. The previous case of cross-reactivity between chicken and fish, reported by these authors, identified a 13-kDa (revealed beta-parvalbumin after mass spectrometry performance) and a 16-kDa IgE binding band (alpha-parvalbumin), being the 16-kD the relevant allergen. Thus, the 13-kD fish parvalbumin seems to be primary sensitizing allergen in the present case. In patients with allergy to fish and chicken, the possibility of cross-reactivity between both foods, should be assessed.