Occupational Inhalant Allergy to Pork followed by Food Allergy to Pork and Chicken: Sensitization to Hemoglobin and Serum Albumin

Abstract

Background: Animal-derived proteins are implicated in primary food allergies, but also in inhalant allergies with secondary food allergy symptoms. The objective of this study was to define the allergen(s) implicated in a case of food allergy to chicken meat, which developed in a person previously sensitized to pork after occupational exposure. Methods: A 42-year-old female with a history of occupational inhalant allergy to pork reported rhinitis, asthma, dysphonia and conjunctivitis 30 min after ingestion of chicken. Skin tests were positive to chicken meat. Protein extracts were prepared from chicken meat. Allergens were characterized by IgE immunoblotting, N-terminal sequencing and ELISA. Results: The patient showed specific IgE binding to chicken meat proteins at 12, 14, 26, 55 and 65 kDa. N-terminal amino acid sequencing identified the 12- and 14-kDa proteins as the α- and β-chain of hemoglobin. ELISA and immunoblot showed specific IgE binding to hemoglobin purified from chicken blood. IgE antibodies to chicken serum albumin were detected by ELISA. Inhibition studies with chicken and porcine hemoglobin as well as with serum albumins demonstrated cross-reactive IgE antibodies. Conclusions: We report a case of confirmed occupational inhalant allergy due to pork followed by food allergy to pork and 3 years later by food allergy to chicken. Porcine and chicken hemoglobin were found to be cross-reactive allergens. Cross-reactivity between porcine and chicken serum albumin was possibly linked to a prior sensitization to cat serum albumin.

Role of Sensitization to Mammalian Serum Albumin in Allergic Disease

“…Interestingly, it was demonstrated that the individual experienced milk-induced food allergy symptoms only after the onset of bronchospasm, so the primary route of sensitization likely was via BSA inhalation, not via BSA ingestion. This modality of sensitization was confirmed by Hilger et al [6].…”

“…A similar case was reported, although the relevant allergen protein was not investigated [34]. Recently, the possibility that primary sensitization to mammalian SA may occur via the respiratory tract has been highlighted [6].…”

Occupational rhinitis: consensus on diagnosis and medicolegal implications

“…Since 2008 several case reports of occupational rhinitis caused by sensitizers, both high and low molecular weight (LMW) agents, seldom if ever described previously, have been published (Table 1) [20][21][22][23][24][25][26][27][28][29][30][31]. In the majority of cases occupational rhinitis was associated with occupational asthma and atopy [20,[22][23][24][25][26][27][28][29][30].…”

Does Sensitization to Foods in Adults Occur Always in the Gut?

“…Although allergy to meats is very rare in adults, a case of occupational airborne allergy to pork followed by food allergy to pork and chicken has been reported [99]. …”

“…Little data support this hypothesis. Anecdotal reports of the onset of food allergy in workers professionally exposed to poultry or bovine meats [92,99] or to latex [32] were reported. Nonetheless, food allergy is uncommon in workers with occupational asthma to crustacean or fish proteins [107], although it sometimes occurs [106].…”