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Kelly&Mom

Which French Fries Can We Have?

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This is a good discussion and is of general benefit to all persons on the gluten-free diet, not just parents of children with celiac disease. I am moving it to the more general gluten-free product discussion forum.

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Thanks i-geek, for the additional insight. It seems though, that whatever the margin for error, combined with the legal limit of 20ppm, always leaves some level of uncertainty. Even when a product is claimed to be gluten-free, the human immune system for sensitive individuals can still react.

As you said, there are tests for IgA, IgE, and IgG. Does this have any bearing on the tests used on food samples?

Another question in my mind is; Suppose a food containing 5ppm gluten sets off an IgA reaction for a given individual, while a 50ppm level sets off an IgE reaction for the same person. Now, if it is the IgA reaction which is causing intestinal damage, but they only feel sick from the IgE reaction, they might conclude a food is safe even when it is still causing damage. I don't recall reading anything that would preclude this from being possible. If anyone knows of research which settles the question, please post a link.

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Thanks i-geek, for the additional insight. It seems though, that whatever the margin for error, combined with the legal limit of 20ppm, always leaves some level of uncertainty. Even when a product is claimed to be gluten-free, the human immune system for sensitive individuals can still react.

As you said, there are tests for IgA, IgE, and IgG. Does this have any bearing on the tests used on food samples?

Another question in my mind is; Suppose a food containing 5ppm gluten sets off an IgA reaction for a given individual, while a 50ppm level sets off an IgE reaction for the same person. Now, if it is the IgA reaction which is causing intestinal damage, but they only feel sick from the IgE reaction, they might conclude a food is safe even when it is still causing damage. I don't recall reading anything that would preclude this from being possible. If anyone knows of research which settles the question, please post a link.

IgA, IgE, and IgG are different types of antibodies produced by the body. IgA is released into the mucosal layers (e.g. gut lumen) and usually acts to neutralize toxins, bacteria, etc. before they can get into the host. IgE binds to antigen (usually allergen) that is on the skin, gut wall, lung surface, etc. It then triggers mast cells (and others, but mast cells are the most prominent) to release histamines and other classic allergic inflammatory proteins. IgG binds its antigen and then triggers other white blood cells (e.g. macrophages) to start an inflammatory response (usually in response to infection). IgG (if I'm remembering my 2nd year classes correctly) is also the antibody that can form huge antibody complexes that clog up the kidneys in diseases like lupus. So these antibody types all have different functions in the body, but their antigen-specific region can all recognize the same protein.

Okay, your first question: no, the antibody subtype produced by a human in response to a food isn't going to have any bearing on the tests used to measure gluten in food. As I said above, antibodies of any subtype can be produced against a foreign protein, depending on what the inflammatory conditions are at the time of first exposure or first reactive exposure (immunization). The antibodies used to measure gluten in foods are most likely derived from a mouse cell line that has been engineered to pump out large quantities of specific antibody for research use.

Second: IMO, an IgE reaction is dangerous. It's actually more immediately dangerous- an IgE-mediated allergic reaction can kill someone in minutes due to anaphylactic shock. If someone is reacting at a level of 50ppm they should be avoiding that food at all costs (regardless of IgA reaction) and carrying an Epi-pen.

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IgA, IgE, and IgG are different types of antibodies produced by the body. IgA is released into the mucosal layers (e.g. gut lumen) and usually acts to neutralize toxins, bacteria, etc. before they can get into the host. IgE binds to antigen (usually allergen) that is on the skin, gut wall, lung surface, etc. It then triggers mast cells (and others, but mast cells are the most prominent) to release histamines and other classic allergic inflammatory proteins. IgG binds its antigen and then triggers other white blood cells (e.g. macrophages) to start an inflammatory response (usually in response to infection). IgG (if I'm remembering my 2nd year classes correctly) is also the antibody that can form huge antibody complexes that clog up the kidneys in diseases like lupus. So these antibody types all have different functions in the body, but their antigen-specific region can all recognize the same protein.

Okay, your first question: no, the antibody subtype produced by a human in response to a food isn't going to have any bearing on the tests used to measure gluten in food. As I said above, antibodies of any subtype can be produced against a foreign protein, depending on what the inflammatory conditions are at the time of first exposure or first reactive exposure (immunization). The antibodies used to measure gluten in foods are most likely derived from a mouse cell line that has been engineered to pump out large quantities of specific antibody for research use.

Second: IMO, an IgE reaction is dangerous. It's actually more immediately dangerous- an IgE-mediated allergic reaction can kill someone in minutes due to anaphylactic shock. If someone is reacting at a level of 50ppm they should be avoiding that food at all costs (regardless of IgA reaction) and carrying an Epi-pen.

OK, thanks. That backs up and expands upon what I've read.

So, the mouse antibodies aren't of a specific type then? Like any will do, or are they just the antigen-specific region?

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OK, thanks. That backs up and expands upon what I've read.

So, the mouse antibodies aren't of a specific type then? Like any will do, or are they just the antigen-specific region?

The specific (or Fab) regions of the antibodies are specific for gluten (or whatever the target protein is). The nonspecific or Fc part (the "tail") of the mouse antibodies used in ELISAs is usually IgG due to the original immunization of the mice- I'm guessing the adjuvant (inflammatory substance that helps the person or animal immunized mount a stronger response against the target protein) used to immunize the mouse from which the antibody-producing cells are derived skews the inflammatory response toward IgG production. But all IgG antibodies from a mouse have the same Fc region- it's the Fab regions that are different so that they can bind to different proteins.

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i've eaten at five guys a few times without any problems. i just tell them i have an 'allergy' and can't have the bun and ask whoever is making my burger to put on fresh gloves. i've never had a problem. as others have said, they don't fry anything else so their fries are safe!

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The monoclonal antibodies used in ELISA are IgG molecules produced by hybridoma tissue culture cells that are a result of fusing B cells from the spleen of an immunized mouse or rabbit with a myeloma cell line. In the case of a gluten ELISA, the animal would be initially immunized with injections of gluten so that it produces a mixture of anti-gluten antibodies.

The way the hybridomas are produced, the final cell line is derived from a single B cell, so all the antibodies are identical ("monoclonal"). The antibodies produced by the hybridoma cell lines are whole IgG molecules, purified from the tissue culture medium. The antigen-specific region detects the gluten. Often in an ELISA a secondary enzyme-tagged or fluorescent antibody that recognizes the heavy chain of the monoclonal IgG is used to provide the assay signal.

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The monoclonal antibodies used in ELISA are IgG molecules produced by hybridoma tissue culture cells that are a result of fusing B cells from the spleen of an immunized mouse or rabbit with a myeloma cell line. In the case of a gluten ELISA, the animal would be initially immunized with injections of gluten so that it produces a mixture of anti-gluten antibodies.

The way the hybridomas are produced, the final cell line is derived from a single B cell, so all the antibodies are identical ("monoclonal"). The antibodies produced by the hybridoma cell lines are whole IgG molecules, purified from the tissue culture medium. The antigen-specific region detects the gluten. Often in an ELISA a secondary enzyme-tagged or fluorescent antibody that recognizes the heavy chain of the monoclonal IgG is used to provide the assay signal.

Yep, what she said.

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Thank you Skylark and i-geek for the in-depth information! Now I just have to get the image of those poor sickly mice out of my head.

You're welcome for the info. If it helps any, it's really not hard on the few mice used to get the cell line started. They do get a few shots to immunize them and an occasional blood test but for the most part they live like pet mice, hanging out in decent sized cages, getting good care and plenty of food. Mice are social and lab mice are generally housed in groups whenever possible, which seems to keep them content. When they are killed for their spleens, it is done as quickly and humanely as possible. You can revise your mental picture to a pile of sleek little white mice, sleeping nose-to-nose in fresh wood shavings with a container of Mouse Chow and a bottle or tube of fresh drinking water on the side of the cage.

Because of the all the issues with using animals, the whole hybridoma technology has been developed to the point that once the antibody-producing cell line is established it can be maintained completely in tissue culture.

By the way, I'm not trying to justify using animals but rather to clarify what happens to them. Debate about use of animals in research can get heated and is probably not the best topic for this particular discussion board.

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You're welcome for the info. If it helps any, it's really not hard on the few mice used to get the cell line started. They do get a few shots to immunize them and an occasional blood test but for the most part they live like pet mice, hanging out in decent sized cages, getting good care and plenty of food. Mice are social and lab mice are generally housed in groups whenever possible, which seems to keep them content. When they are killed for their spleens, it is done as quickly and humanely as possible. You can revise your mental picture to a pile of sleek little white mice, sleeping nose-to-nose in fresh wood shavings with a container of Mouse Chow and a bottle or tube of fresh drinking water on the side of the cage.

Because of the all the issues with using animals, the whole hybridoma technology has been developed to the point that once the antibody-producing cell line is established it can be maintained completely in tissue culture.

By the way, I'm not trying to justify using animals but rather to clarify what happens to them. Debate about use of animals in research can get heated and is probably not the best topic for this particular discussion board.

Yep. My mice are mostly black instead of white, but otherwise they live in conditions like those described. They're in a temperature-controlled, well-ventilated room and a vet tech checks them regularly to make sure everyone's healthy. And it's true, they do choose one corner of the cage and sleep in a big pile.

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