Anaphylactic reactions???

jgaglio1

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From the time I first got into the hobby, I have heard that "allergic reactions" were the primary danger of tarantula bites. While I have read of significant toxic reactions to T venom, particularly to Poecilotheria envenomations, I have never seen a documented, or even a reported case of anaphylaxis.
There are plenty of bite reports out there and one would think that if an allergic reaction were possible we would have seen one somewhere. Are we simply passing along a dramatic horror story, or is there some medical documentation somewhere?
 

cacoseraph

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i believe the peptides tara venom are significantly different than hymenoptera venom and that allergic reaction is not likely at all
 

Thoth

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No there is no medical documentation or case study of anaphlaxis in reaction to a spider bite, that I have been able to find and I have searched. There was one instance mentioned of elevated IgE (an indicator of allergic reaction) measured a week or so after envenomation by a t, though no direct causality and unlikely caused by the bite.

It is highly debatable (in my opinion highly unlikely) that t venom is even allergenic, due to its make up consisting of small peptides and other small organic molecules. Recognition for a majority of immune-meditated responses having antigen size be a key factor.
 
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pinkzebra

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I remember reading somewhere here on the board, probably about a month or two ago, that T venom is peptide based and the human body does not respond to peptide based venom with an allergic reaction. Most other venoms (bee, wasp etc) are protein based and the human body does sometimes respond to protein based venoms with an allergic reaction. I don't know where the article/discussion was on here and don't have time to look for it now, but I do remember reading it. Maybe the person who supplied the info will see this and ring in. If not I will search for it later when I have more time. I think they included a link to an article about it also, but I'm not sure.
 

ShadowBlade

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I think someone would have died by now, (and documented) if there was a threat of serious allergenic reaction.
 

lucanidae

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that T venom is peptide based and the human body does not respond to peptide based venom with an allergic reaction. Most other venoms (bee, wasp etc) are protein based and the human body does sometimes respond to protein based venoms with an allergic reaction.
This dosen't make much sense to me. A peptide is a string of amino acids. Proteins are strings of amino acids. A protein is built from peptides, usually anywhere between one and four. As an example, the protein hemoglobin is built from four peptides.

Seeing as how they are built from the same basic parts and assume similar shapes, why would the reaction be different?

I've never heard of an allergic reaction either though, although it seems humans can be allergic to pretty much anything.....
 

Crotalus

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The size of the proteins are essential when to get a anaphylaxis. Snake and bee venom consist of large protein while most spider venom are smaller protein called peptides and they are not causing allergic responses.
 

Nate

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This link has a lot info but I do question the source of “Instances of cardiac failure reported”.

I went to the source link and did a search Poecilotheria and got a “The Truth About Regalis” which lead me to a bogus ad.

http://en.wikipedia.org/wiki/Spider_bite

Regarding peptides they are involved in abnormal tissue functions such as cardiac arrhythmias, congestive heart failure, elevated calcium levels in muscular dystrophy, and angiogenesis-supported tumor growth.

The protein may not be Y shaped antibodies but peptides can induce other issues outside of anaphylactic shock that can be harmful. I don’t think it’s a stretch to tell someone with a chronic heart condition they should avoid a bite.
 
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Thoth

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This dosen't make much sense to me. A peptide is a string of amino acids. Proteins are strings of amino acids. A protein is built from peptides, usually anywhere between one and four. As an example, the protein hemoglobin is built from four peptides.

Seeing as how they are built from the same basic parts and assume similar shapes, why would the reaction be different?

I've never heard of an allergic reaction either though, although it seems humans can be allergic to pretty much anything.....
Like Lelle said it is size, the difference between a peptide and a protein is generallynumber of amino acids which make it up (it is a rather arbitrary the distinction), peptides also refer to fragments of protein as well.

I don't know why (I might have been sleeping during that lecture) but for some reason small molecules do not commonly trigger an allergic immune response

Immunogenicity of an antigen is related to its size, example insulin is to small to trigger an allergic reaction but certain formulations need to be refrigerated if not it will form aggregates which are large enough to trigger an allergic reaction. Its common in the lab to develop antibodies for small peptides is to attach them to much larger proteins so them become immunogenic.

Its not to say that the venom will not trigger some sort of immune/inflammatory response (usually non-immunoglobulin mediated response) just not an allergic one.
 

Thoth

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This link has a lot info but I do question the source of “Instances of cardiac failure reported”.

I went to the source link and did a search Poecilotheria and got a “The Truth About Regalis” which lead me to a bogus ad.

http://en.wikipedia.org/wiki/Spider_bite

Regarding peptides they are involved in abnormal tissue functions such as cardiac arrhythmias, congestive heart failure, elevated calcium levels in muscular dystrophy, and angiogenesis-supported tumor growth.

The protein may not be Y shaped antibodies but peptides can induce other issues outside of anaphylactic shock that can be harmful. I don’t think it’s a stretch to tell someone with a chronic heart condition they should avoid a bite.
Spider venom is completely different creature than that of tarantula venom.

No one is saying that T venom is not potentially dangerous, the peptides that make it up are ion channel inhibitors which would have neurological and muscular effects that can have serious effects.
 

Nate

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Are you bring up “spider venom” because of the link name or are saying that they can’t induce cardiac issues? :?

I think the term “allergic reactions” is tossed around a lot due to the possibility of necrosis and people may equate that to an “allergic reaction”.
 

Crotalus

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Are you bring up “spider venom” because of the link name or are saying that they can’t induce cardiac issues? :?

I think the term “allergic reactions” is tossed around a lot due to the possibility of necrosis and people may equate that to an “allergic reaction”.
Its tarantula venom the post is about, not spider venom in general. Other spider venom contain peptides aswell, just like tarantula venom, but some have other more unpleasant surprises that tarantula venom lacks such as renal failure and cardiac arrest.
 

Thoth

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Are you bring up “spider venom” because of the link name or are saying that they can’t induce cardiac issues? :?

I think the term “allergic reactions” is tossed around a lot due to the possibility of necrosis and people may equate that to an “allergic reaction”.
I just brought it up because of the link you had, people commonly equate the two due to the closeness of the two families, but they have different make up. Not making any judgement on the effects of spider venom which has quite a bit of literature documenting its effects.
 

mikeythefireman

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My understanding was anything that triggers an immune response can lead to anaphylaxis. Whatever chemical (peptide/protein/bubblegum) that the immune system recognizes as foreign can create the overwhelming immune response. This is the info that was passed out at every allergy/immunology lecture/speech/discussion that was held in the San Diego area from '02-'05. (I'll go to anything to get out of clinic duty);)

(The following is an assumption we reached after many hours of late night discussions regarding the vagaries of the human immune system)

Many exagerrated immune responses are never diagnosed at all. Because anaphylaxis can present as cardiac, many patients that fit the appropriate demographic for cardiac patients simply expire from mis-diagnosis. We theorized that the numbers could be in the thousands every year in the U.S. alone.

Several of my docs saw patients post cardiac arrest who had been given Epi as a cardiac drug. Without funding they could never pursue this line of thinking, but the world sure seems round when viewed from that perspective.
 

Nate

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Today I had a long talk with a Toxicologist at work during lunch regarding the subject matter. Due to our discussion and further keyword searches I have completely changed my position on the subject.

It doesn’t matter if Tarantula venom consists of Peptide Antibodies its still can trigger an allergic reaction. The question is what receptors the antibodies bind to. If the binding causes a histamine response than it would be classified as an allergic reaction which in high-grade histamine responses would lead to anaphylaxis.

All spiders (including Theraphosidae) venom is classified into six distinct clinical syndromes:
1) latrodectism and family-related steatodism
2) loxoscelism
3) non-Loxosceles necrotic araneism
4) funnel-web neurotoxicity
5) phoneutrism
6) allergic and foreign body araneism.

Theraphosidae is classified as a 6 (allergic and foreign body araneism). This is why we see the anaphylactic reaction warnings and explains the possibilities of necrosis/myonecrosis.

Source: The Global Epidemiology, Syndromic Classiffication, Management, and Prevention of Spider Bites, James H. Diaz 2004:
http://www.ajtmh.org/cgi/reprint/71/2/239.pdf#search="tarantula venom Histamine response"
 
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Thoth

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Today I had a long talk with a Toxicologist at work during lunch regarding the subject matter. Due to our discussion and further keyword searches I have completely changed my position on the subject.

It doesn’t matter if Tarantula venom consists of Peptide Antibodies its still can trigger an allergic reaction. The question is what receptors the antibodies bind to. If the binding causes a histamine response than it would be classified as an allergic reaction which in high-grade histamine responses would lead to anaphylaxis.

All spiders (including Theraphosidae) venom is classified into six distinct clinical syndromes:
1) latrodectism and family-related steatodism
2) loxoscelism
3) non-Loxosceles necrotic araneism
4) funnel-web neurotoxicity
5) phoneutrism
6) allergic and foreign body araneism.

Theraphosidae is classified as a 6 (allergic and foreign body araneism). This is why we see the anaphylactic reaction warnings and explains the possibilities of necrosis/myonecrosis.

Source: The Global Epidemiology, Syndromic Classiffication, Management, and Prevention of Spider Bites, James H. Diaz 2004:
http://www.ajtmh.org/cgi/reprint/71/2/239.pdf#search="tarantula venom Histamine response"
Nate did you read the article? ( to same you nad others time section pertinent to tarantulas starts on pg 246 mid-way through the second column) It deals mostly with the dangers of the urticating hair particularly when it comes into contact with the eye. Noone has said you can't have an allergic reaction to urticating hairs. Nothing there supports allergic reaction to tarantula venom.

Yes if there are antibodies against a certain antigen or epitope (antibodies are specific to what they bind to) there is risk of allergic reaction (or anaphlaxis). The thing is you're body does not normally raise antibodies aginst small peptides (50 or smaller residues (amino acids)), macromolecules, or non-organics. Without antibodies being able to be formed against them there is little chance of allergic reaction (and subsequently anaphlyaxis)

Also I agree the term allergy (or allergic reaction) is bandied about rather cavalierly. It is aspecific typoe of immune response. Not all immune responses are allergic reactions.
 
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