Sashimi or kebab? The effect of cooking on crustacean allergy

Allergy to crustaceans is complicated, and
can differ depending whether the food is
cooked or raw.

 by Dr Jodie Abramovitch (one of the authors on the study)

Allergy to crustaceans, such as crab and prawns, is a major cause of food induced anaphylaxis. To more accurately diagnose and treat crustacean allergies, investigation into the underlying immunological mechanisms that cause the allergy is necessary.

Researchers within the Monash University Departments of Allergy, Immunology and Respiratory Medicine (AIRMed) and of Immunology and Pathology have published a paper investigating the effect of cooking of crab and prawn species on immune cells involved in the allergic response.

For the first time, this study looked at the response of four different immune cell subsets – CD4+, CD8+,  and CD56+ lymphocytes, and Foxp3+ regulatory T cells -  to raw and cooked crustaceans in crustacean-allergic individuals.

Results from this study support previously published data from the same group (Abramovitch et al., PlosONE, 2013) that showed that IgE-antibody (clinical diagnostic marker of allergy) reactivity was increased to cooked crustaceans in allergic individuals. Interestingly, in the recent study it was found that lymphocyte reactivity, as indicated by cell proliferation and cytokine production, appeared to be decreased in response to cooked crustaceans when compared to raw (ie. raw crustaceans stimulated higher levels of lymphocyte proliferation and cytokine production).

The induction of regulatory T cells was also decreased. Of particular importance was the ability of both raw and cooked crustaceans to induce secretion of the cytokine interleukin-4 (IL-4) by proliferating CD4+ lymphocytes in allergic individuals, as this cytokine promotes the production of IgE antibodies. These novel findings have important implications for diagnosis of crustacean allergy and the development of future therapeutics.

This study highlights the complexity of allergic disease and the need for further in-depth studies to improve the management of crustacean allergic patients clinically.

Abramovitch JB, Lopata AL, O'Hehir RE, Rolland JM. Effect of thermal processing on T cell reactivity of shellfish allergens - Discordance with IgE reactivity. PLoS One. 2017 Mar 8;12(3):e0173549. doi: 10.1371/journal.pone.0173549. eCollection 2017.