Nice Summary of Shrimp Protein

[Macabre]

http://inbio.com/US/images/pdfs/Focus_on_tropomyosin_8-13-09.pdf

Shellfish is the #1 cause of food allergy in adults in the Unites
States (1). A recent survey found that 1 in 50 Americans has shellfish allergy (2). Most shellfish species, provoking allergic reactions belong to the class crustacea, which includes shrimp, crab, crawfish and lobster with shrimp being the leading culprit. Since 1970 shrimp consumption has more than tripled and it is expected that allergy to shellfish will continue to be on the rise

Tropomyosin is a highly conserved protein, with multiple isoforms that is found in both muscle and non-muscle cells of all species of vertebrates and invertebrates (Table 1). Allergenic tropomyosins are found in invertebrates such as crustaceans, arachnids
(house dust mites), insects (cockroaches) and mollusks (e.g. squid). but there is a lack of allergenic cross-reactivity between these tropomyosins and those from vertebrates such as bony fish, beef, pork or chicken, which are considered nonallergenic (8,10)

Clinically relevant allergenic tropomyosin in crustaceans other than shrimp are found in lobster (Pan s 1, Hom a 1) (11-12), crab (Cha f 1) (13), squid (Tod p 1) (14), snail (Tur c 1) (15) and oyster (Cra g 1) (16). Those identified in other invertebrates are found in house dust mites (Der f 10, Der p 10) (17-18), and cockroaches (Per a 7, Bla g 7) (10,19-21). Immunological cross-reactivity has been demonstrated between crustaceans, cockroaches and House dust mites, suggesting that tropomyosin is an important crosssensitising panallergen (4,10). Some studies suggest that this cross-reactivity may be clinically relevant. Sensitization and allergic symptoms to ingested snails and shrimp have been reported following specific immunotherapy with dust mite (6) . IgE antibody 36 kD reactivity to shrimp among Orthodox Jews, unexposed to shellfish, was demonstrated and appeared to result from cross-reacting tropomyosin in subjects allergic to mite and/or cockroach (22).

[CMdeux]

Wow-- great find.  Will read when I'm operating at better cognitive capacity.  I'm very interested in how cross-reactive the mollusc/shirmp tropomyosins are.

As you might recall, one of my very worst reactions ever was to squid-- that I had rinsed multiple times in an effort to reduce possible XC.  We'd assumed that it was probably just cross-contamination, but now I wonder.

I also wonder because of the aerosol reactivity that I evinced toward "scallops" that DH was pan frying one night.  Scallops are quite commonly mislabeled, of course, and probably also commonly cross-contaminated, but it's interesting how intense that reaction was.  Seemed suspect even at the time for merely being to a contaminated product-- it was more like he was cooking WITH an allergen.

I just avoid it all at this point-- no escargot for me in France, tyvm.   But it intrigues me.  I have to wonder if my primary allergy isn't to something other than shrimp tropomyosin.

[notashrimpwimp]

It's really odd because I am allergic to both shellfish and dust mites, but have reacted in the past to scallops being microwaved and also steaming calamari.

I guess I'm going to have to forgo that tempting can of escargot I saw in the grocery store yesterday.  (Although one has to wonder what effect canning has on the quality of such a squishy foodstuff!)

[forvictoria]

what I don't understand is I test positive for Shrimp, dust mites, and cockroaches, on several blood tests, but when I took the phadia shrimp component package I test negative for the protein f351 rPen a 1 Tropomyosin. Any ideas?

I tried talking about the results with my allergist, but he doesn't take much stock in the component test. He ordered the test because I asked for it. I don't even think he was aware of it.

[PurpleCat]

I don't understand the science of all of this but for DD:

She tests positive for dust-mites, cockroaches,  and shell fish.  She tests negative for mollusks.

She eats shrimp quite a bit.  Clams give her a reaction.  She eats and loves scallops.  I won't go there with lobster.  The clam bit was enough for me and she's happy with shrimp and scallops.

[BrandyWineSeattle]

I've been told that I should avoid shellfish, mollusks and also squid, octopus and sea cucumber.  I assumed that they were all the same.