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Posted by: Ronagon (Guest), Thursday, August 16, 2007, 9:08am
I've never been able to make logical sense of a few things regarding the Lewis antigen status thing...

1) What, precisely, do Lewis antigens do, whether secreted or otherwise?

2) Are Lewis antigens measured through a blood test?  After all, if they were just measured with a saliva test, how would you be able to distinguish between a+b- and a-b-, when both would presumably still be bound on a non-secreted cell surface?

3) If one gene controls both Lewis antigen secretion AND blood type antigen secretion, then how is it possible that you could have a Lewis double-negative person who could also be either undetermined as a blood type secretor or non-secretor?  That seems like the action of an independent, though linked, gene or something...
Posted by: yaman, Thursday, August 16, 2007, 9:25am; Reply: 1
Hi Ron,

I think your confusion arises from "secretion". The way I understand is, it is about whether the ABH antigens being secreted or not, and not about secreting Lewis antigens (I hope I didn't further complicate it).

Anyway, had you been a secretor, then you would be secreting your H antigen in your bodily fluids. You are a nonnie, so you are not able to do this.

The most accurate way of finding whichever you are is the saliva testing, i.e. looking for ABH antigens in one's saliva.

On the other hand, Lewis antigens can only be determined by blood testing. Lewis a+b- is always a non-secretor, and Lewis a-b+ is always a secretor, again the secretion here means that of the ABH antigens and not the Lewis antigens.

Lewis a-b- is a rare case, Lewis a+b+ being even rarer, and in both cases the Lewis typing does not say anything about secretor status. In such cases, it is best to have a saliva test done. Likewise, as you indicated, a saliva test won't tell you whether you are a Lewis a-b+ nonnie or a Lewis a-b- nonnie.

Cheers,
Yaman
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 9:30am; Reply: 2
Actually, I did a google search, and I found an excellent graphic that I think cleared everything up for me:

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=glyco.figgrp.1077

In the graphic, you'll see that there are two ways to test "positive" for the Lewis antigen, but only the top pathway is correlates with secretion.  The second pathway from the top does not correlate with secretion, presumably because it's lacking that outer fucose molecule.  However, it does test positive for Lewis antigenicity, because it does have that inner fucose molecule.

Apparently, here's the Dick Tracy Decoder Ring for Lewis antigenicity:  the presence of an outer fucose correlates with secretion, while the presence of an inner fucose correlates with the ability to merely display antigenicity properties.

In the last two pathways, you'll see that the third pathway possesses that outer fucose, so it secretes... but, since it doesn't possess that inner fucose, it doesn't display antigenicity.  To my understanding, this would be the example of that mysterious secretor who tests Lewis negative.

And, we are also told, there is one other way that a person could test Lewis negative, but be a non-secretor.  I think this is exemplified in the final pathway, in which no fucose molecules are tacked on at all.  In other words, since there is no inner fucose, it doesn't display Lewis antigenicity... and, since there is also no outer fucose, it doesn't secrete, either.  

And so, to sum it all up, I think that the four rows can be described as follows:

Top row:        a-b+
Second row:   a+b-
Third row:      a-b- (but blood type antigen secretor)
Fourth row:    a-b-  (but blood type antigen non-secretor)

Am I right about this?  Or is the top row an example of that extremely rare thing, the a+b+?
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 9:39am; Reply: 3
yaman,

Thanks for the info, but I'm still confused with how a person could secrete their blood type antigen, but be a Lewis double-negative, if both systems are controlled by the same gene.  Is there some special failure in blood type antigen secretors who do not also attach that outer fucose molecule, thus testing a-b+?  

I mean, if they're double-negative, there should be no way that secretion should happen, because the same gene that would attach that outer residue would also create a secretable product, automatically... thus making a double-negative always a non-secretor.

Now, if they're both controlled by the same gene, to my mind there should be some external influence going on that causes independence between the two systems.  But if they're not really the same gene, then I suppose they could operate independently somehow, and produce these results.

It's the seeming contradiction here that's driving me nuts.
Posted by: yaman, Thursday, August 16, 2007, 9:40am; Reply: 4
Ron! Brilliant!

Yes you are right, it's all about Se and Le which are responsible for locating the fucose. Thank you for showing it like that.

Now Le a+b+ is another question. For once you have the Se locus a1-2 FucT, then all a should be converted to b. The top pathway shown there is definitely Le a-b+. We have to look for a+b+ elsewhere I guess.

Cheers,
Yaman
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 9:44am; Reply: 5
Here is what the article says about the Lewis graph I just posted:

Quoted Text
The Lewis A antigen (Lea) is synthesized by an α1–3/1–4 fucosyltransferase encoded by the Lewis (Le) blood group locus (Figures 16.15). The Lewis B antigen (Leb) is synthesized by the concerted actions of the Lewis α1–3 fucosyltransferase and the α1–2 fucosyltransferase encoded by the Se blood group locus (Figure 16.15). The nature of the alleles at an individual's Le and Se loci determines the complement of Lewis-active oligosaccharide molecules that will be constructed in that individual (Figure 16.15). Secretor-positive individuals convert type-1 oligosaccharide precursors to type-1 H molecules. The resulting type-1 H determinants may then be used as precursors by the Lewis locus-encoded α1–3/1–4 fucosyltransferase to form the Leb structure (Figure 16.15). Individuals that construct Leb exhibit the Le(a-b+) phenotype (Figure 16.15). Nonsecretors do not synthesize type-1 H determinants in secretory epithelia, but such unsubstituted type-1 molecules can be converted to Lea-active oligosaccharides by the Lewis α1–3/1–4 fucosyltransferase. These individuals exhibit the Le(a+b-) phenotype (Figure 16.15). Individuals that are homozygous for null alleles at the Lewis locus can have two different phenotypes. Such Lewis-negative individuals who are positive for secretor status construct type-1 H determinants, but these structures remain unconverted to Leb determinants (Figure 16.15). These persons exhibit the Le(a-b-) phenotype. In contrast, in individuals who are Lewis-negative nonsecretors, type-1 precursors are not substituted by either the Lewis or the Secretor fucosyltransferases, accounting for absence of Lea, Leb, or H structures, and their Le(a-b-) phenotype.


After really reading this carefully, it seems to describe the statuses I laid out initially... But, if this is really the case, what does an a+b+ look like?
Posted by: yaman, Thursday, August 16, 2007, 9:49am; Reply: 6
OK, here's something I found:

http://www.springerlink.com/content/t1845m6323757338/

" We also show that Lewis epitopes on longer and/or more complex core chains appear to be predominant in the Polynesian Le(a+b+) samples. The formation of these extended glycolipids is compatible with the concept that in the presence of reduced secretor fucosyltransferase activity, increased elongation of the precursor chain occurs, which supports the postulate that fucosylation of the precursor prevents or at least markedly reduces chain elongation."

Seems it's about a reduced Se activity..
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 9:52am; Reply: 7
Thanks, yaman.  I hope I've got it right.

If I've truly got it right, then my only question is:  What in the world does a+b+ look like, since the top pathway in the figure seems fully saturated with fucose residues on both the inside and outside?
Posted by: yaman, Thursday, August 16, 2007, 9:53am; Reply: 8
Here's another and more comprehensive explanation of Le a+b+:

http://cebp.aacrjournals.org/cgi/content/full/10/9/971/F1

In this case, Le enzyme activity is five times greater than Se enzyme activity, hence both Le a and Le b are present.
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:00am; Reply: 9
Ohhhhh... waitaminute....  I think I understand now.  

An a+b+ might just be like an AB blood type:  it might be an example of somebody who produces BOTH nonsecreted Lewis antigens AND secreted Lewis antigens at the same time.

I think the whole point of the Lewis system, is that it's a discrete construct, kind of like binary switches... In theory, people either ONLY produce non-secreted Lewis antigen OR ONLY produce secreted antigen.

However, in some people, they might produce both.  In other words, their cells would perform the pathways of BOTH row 1 and row 2.

If I'm right, that means the binary classification of this system is a convenient conceptual abstraction, but not necessarily reality.

I say this because the article you posted, talks about two groups who were both a+b-, yet one was a nonsecretor, and the other was a partial secretor.  Apparently, the system is a good deal more "analog" than purely "binary" or "digital"... more "continuous" than "discrete".
Posted by: yaman, Thursday, August 16, 2007, 10:02am; Reply: 10
I agree.. I think the mystery is solved now :)
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:03am; Reply: 11
Quoted Text
In this case, Le enzyme activity is five times greater than Se enzyme activity, hence both Le a and Le b are present.


Yes, yes.  Thank you for saying that.  It all makes perfect sense now.  Apparently the Lewis "a" form doesn't secrete (and, I guess, correlates with blood type antigen non-secretion), but the Lewis "b" form does (and, I guess, also correlates with blood type antigen secretion).  
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:05am; Reply: 12
This raises another question in my mind:  I wonder if the ability to produce both A and B blood type antigens, might also be due to the same gene that allows someone to produce both Lewis a and b antigens simultaneously...

Actually, no, that wouldn't work, because the "a" form is always non-secreted, while the "b" form is always secreted.  And, with the "AB" blood type antigen, you can have both either secrete or non-secrete simultaneously.  So they don't even behave the same way...
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:07am; Reply: 13
You know, I think I might actually produce a visual graphic that also includes how an a+b+ is produced...  it would visually explain all five possibilities.
Posted by: yaman, Thursday, August 16, 2007, 10:08am; Reply: 14
Yep, that's the way I get it too.

And while we are at it, Lewis a-b+ patients with gastric carcinoma can exhibit an anomalous expression of Lewis a:

http://www3.interscience.wiley.com/cgi-bin/abstract/112687203/ABSTRACT?CRETRY=1&SRETRY=0

This gets deeper and deeper ;D
Posted by: yaman, Thursday, August 16, 2007, 10:11am; Reply: 15
Quoted from Ronagon
You know, I think I might actually produce a visual graphic that also includes how an a+b+ is produced...  it would visually explain all five possibilities.


Actually there is a graphic, you can find it by following the link in my post (reply 8-14)..
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:11am; Reply: 16
Ah, well, I just clicked on that link, and they want me to pay to view it.  Ha ha ha ha  So I'll take your word for it.
Posted by: yaman, Thursday, August 16, 2007, 10:17am; Reply: 17
Funny!,

OK, try this one, Figure 1, and it also shows how the secretion is effected:

http://www.jbc.org/cgi/content/full/271/16/9830
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:18am; Reply: 18
Okay, I went back and looked at that link.  Thanks again.

Strictly speaking, however, since the secreted form of Lewis, Lewis b, has both the inner and the outer fucoses, I would think it would register as both Lewis a AND Lewis b, thus making it a+b+... but I suppose what they mean when they talk about double-positive, is when Lewis is detected both on tissue surfaces, and out in fluids.

I guess I just think they need to be more precise in their terminology here.  It's ambiguous to me, and it caused my confusion.
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:23am; Reply: 19
Ah.  I see.  I think. 

So, would a+b+ result from a mixture of partial completions of the two-step, Se-Le Lewis "b" pathway, whereby sometimes it might stop after the Se enzyme does its thing, and other times it goes all the way through to the Le enzyme doing its thing, thus producing both "a" and "b" forms?  Or does a+b+ come about from both the "a" AND the "b" pathways both being performed to full completion (and, perhaps, a partial completion of the "b" pathway here, too)?

You know, I'm really glad you posted that last link.  It helps even more...
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:26am; Reply: 20
My only complaint about that last diagram you showed, is that it gives the formula molecular diagrams, rather than a purely pictorial one, which would simplify things a lot more.

If you could represent the information in that last diagram, in the same visual manner as the very first diagram I posted, then that would make it clear as a bell to just about anyone, notwithstanding those in need of a neurologist.
Posted by: yaman, Thursday, August 16, 2007, 10:29am; Reply: 21
The way I see it is; when Le activity is higher compared to Se activity, you end up with Le converting the Type 1 H (to Le b antigen), as well as some of the Type 1 precursor (to Le a antigen) before they had a chance to be converted to Type 1 H by Se due to Se's lower activity, so you end up with both antigens.

So actually, all you have to do is to put the top and the second pathways together in order to show the a+b+ case.

And I'm glad you started this thread, I had the opportunity to learn more about Lewis system :)
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:31am; Reply: 22
Quoted Text
The way I see it is; when Le activity is higher compared to Se activity, you end up with Le converting the Type 1 H, as well as the Type 1 precursor before it had a chance to be tackled with Se due to Se's lower activity, so you end up with both antigens.


Yes, but that's entirely the point of my last question:  Does a+b+ result from this way that you just described here -- in other words, from the cells performing both "Lewis a" and "Lewis b"pathways, or from the cells both partially and fully performing the "Lewis b" pathway only?
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:33am; Reply: 23
In other words, what you seem to just be describing is a situation whereby BOTH pathways are conducted.  But my point is that, what if the results happen from both full and partial completions of just the LEFT-hand pathway in the diagram?
Posted by: yaman, Thursday, August 16, 2007, 10:37am; Reply: 24
My understanding is, both paths work simultaneously, it's just that more Le are at work than Se.
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:49am; Reply: 25
Okay, I understand what you're thinking now.  It just might be right.

But a different thought just occurred to me:  When the "Se" enzyme produces that H type 1 antigen, is that just the secreted blood type O molecule?  After all, it looks the same, right?  Does that set of pathways produce ALL blood type antigens, or only the secreted versions?

And if that's the case, is the non-secreted form, though identical, produced through the actions of a completely different gene at chromosomal site 9q34, rather than the secreted form, which is produced at either chromosome 11 or the other one?  Is it really the case that both the secreted and non-secreted forms of all the various blood type antigens are chemically indistinguishable from each other, even though they're produced at two different chromosomal sites?

If so, that's pretty interesting.
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 11:12am; Reply: 26
You know, after sifting through all these various diagrams, struggling through the published explanations, and talking this through with each you (which I'm very grateful to you for doing with me, by the way...), I've come to the conclusion that this was a very, very difficult and complicated pathway to grasp before we even started, and merely trying to describe it in words, is not nearly adequate.

To really make this clear, requires a full, pictorial diagram of some clarity and quality.
Posted by: yaman, Thursday, August 16, 2007, 11:22am; Reply: 27
The miracle of Life, is never simple Ron :) even though you have started with what at first glance seemed to have a simple answer.

Hopefully other minds will join this exciting thread..

Posted by: Ronagon (Guest), Thursday, August 16, 2007, 11:31am; Reply: 28
I've just been looking through this link for the book, "Essentials of Glycobiology", and it has some really amazing diagrams of all kinds of glycoconjugate molecules:

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=glyco

In fact, there are a number of informative books at that website:

http://www.ncbi.nlm.nih.gov/books
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 11:48am; Reply: 29
And so, my final understanding here is as follows:

1) All secreted blood type antigens (A, B, and O), as well as Lewis antigens A and B, begin as "Type I" compounds.

2) This type I compound is added upon by the secretor gene, to create the to-be-secreted "H" antigen (also known as the "O secretor" antigen, which is, of course, secreted).

3) This to-be-secreted "H" antigen is added upon by the Lewis enzyme to create the Lewis "B" antigen, which is also secreted.

4) The original "Type I" compound (from "1)") can also be added upon by that same Lewis enzyme, to yield the Lewis "A" antigen, which is not secreted.

5) The "H" antigen (also known as the "O secretor" antigen, from "2)") can be added upon by the ABO gene at 9q34 to yield either an "A Secretor" or "B Secretor" antigen, which, as the names imply, are secreted.

6) In the case of the non-secreted blood types, the "H" antigen which is to be used as the base to build the non-secretor A's, B's, and O's, is made elsewhere, by some gene besides the secretor gene, though the structure will be identical.  However, the ABO gene at 9q34 will still attach the "A" and "B" molecules to form the non-secretor "A" and "B", just as they did with the to-be-secreted forms.

If I've got this all right, I'm astonished... and a little relieved, at last.
Posted by: yaman, Thursday, August 16, 2007, 12:13pm; Reply: 30
I'm afraid I have argue the point 1 :B

In the first link you've provided above, it says that there are actually four typs of precursors to the ABO blood groups.

http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=glyco.section.1068
Posted by: Lola, Thursday, August 16, 2007, 8:59pm; Reply: 31
http://www.ncbi.nlm.nih.gov/projects/mhc/xslcgi.fcgi?cmd=bgmut/systems_info&system=lewis
gosh guys, hope you reach a verdict!!
I m trying to learn something here!!! lol
http://www.dadamo.com/wiki/wiki.pl/Lewis_Blood_Group

Quoted Text
A Le(a+b+) phenotype may occur in individuals in whom the expression of H is decreased due to a mutation in the FUT2 gene (385A>T). This phenotype may also occur due to incomplete fucosylation of type H precursor sites. Failure to express FUT3 will result in a Lewis null phenotype [Le(a-b-)], irrespective of the Secretor status. However, one should note that the latter phenotype may also be observed upon the absence of Le glycolipids from the membrane, as may occur in patients with certain cancer or other conditions.

Quoted Text
Le(a+b+), is found in the Oriental population and appears to be due to a weak secretor gene.

Quoted Text
The le gene is an amorph. Persons who are lele produce no Lea and no Leb antigens. RBCs that type as Le(a+b+) are only rarely found when human antisera are used in typing. Such RBCs are seen more frequently when more potent monoclonal anti-Lea and anti-Leb reagents are used.

a rare bird!
http://www.dadamo.com/bloggers/ask/archives/00000234.htm
Posted by: Ronagon (Guest), Thursday, August 16, 2007, 10:56pm; Reply: 32
yaman,

Thanks for posting that.  I wonder if all those ABO variants still act as blood type antigens, in the same way.  Maybe they're created at different sites or something.



Lola,

Thanks for posting that.  I just realized that Dr. D has the same chart as was on that link yaman posted to me...
Posted by: Lola, Thursday, August 16, 2007, 11:05pm; Reply: 33
right!
Posted by: Don, Tuesday, August 21, 2007, 7:31pm; Reply: 34
Quoted from yaman
Lewis a-b- is a rare case,...

According to Dr. Kruzel in his 2003 IfHI presentation in the USA

Lewis a-b- = Whites 6%  Blacks 22%
Posted by: Don, Tuesday, August 21, 2007, 7:49pm; Reply: 35
Quoted from Ronagon
I've never been able to make logical sense of a few things regarding the Lewis antigen status thing...

1) What, precisely, do Lewis antigens do, whether secreted or otherwise?

Lewis is not secreted, only ABO is secreted.
The secretor factor (Se) might be considered either a physiologic trait or an honorary blood group. The individual who is a so-called secretor has demonstrable ABH blood group antigen in the saliva and other body fluids; the nonsecretor does not. Secretor is dominant.

Genetically independent of the ABO blood groups is the secretor system which comprises two allelomorphic genes, Se which causes secretion in saliva and other fluids of the antigen or antigens corresponding to the individual's ABO group, and se which, in the homozygous condition determines non-secretion. Heterozygotes are secretors.


Quoted from Ronagon
2) Are Lewis antigens measured through a blood test?  After all, if they were just measured with a saliva test, how would you be able to distinguish between a+b- and a-b-, when both would presumably still be bound on a non-secreted cell surface?

According to Dr. Kruzel in his 2003 IfHI presentation you use 1 drop of anti-LeA or anti-LeB in two test tubes to check for agglutination of LeA and LeB, respectively. If you don't find any agglutination in either test tube then that would represent Lewis a-b-.

Quoted from Ronagon
3) If one gene controls both Lewis antigen secretion AND blood type antigen secretion, then how is it possible that you could have a Lewis double-negative person who could also be either undetermined as a blood type secretor or non-secretor?  That seems like the action of an independent, though linked, gene or something...

See answer to 1 above. Lewis and secretor are 2 different, but somewhat related issues.
The synthesis of the epitopes is dependent on the interaction of two different fucosyltransferases, products of two different loci: FUT2 or the secretor (Se) locus of the H/h blood group system that encodes the alpha (1,2) fucosyltransferase (FUT2), and the FUT3 locus that encodes the alpha (1/3,1/4 fucosyltransferase (FUT3).
...
Clearly, the genotype of an individual at the FUT2 and FUT3 loci determines the Lewis phenotype. In the presence of FUT2 alleles that express type 1 H determinants, the phenotype will be Le (a-b+), but individuals in whom the FUT2 gene is not expressed, it will be Le(a+b-). A Le(a+b+) phenotype may occur in individuals in whom the expression of H is decreased due to a mutation in the FUT2 gene (385A>T). This phenotype may also occur due to incomplete fucosylation of type H precursor sites. Failure to express FUT3 will result in a Lewis null phenotype [Le(a-b-)], irrespective of the Secretor status.

I suggest you read at least the whole introduction section of the article.
Posted by: Don, Tuesday, August 21, 2007, 8:17pm; Reply: 36
Quoted from Ronagon
BOTH nonsecreted Lewis antigens AND secreted Lewis antigens at the same time.

I have already addressed the issue that secretor/non-secretor applies to ABH, not Lewis, in a previous post.

Posted by: Don, Tuesday, August 21, 2007, 8:19pm; Reply: 37
Quoted from Ronagon
And so, my final understanding here is as follows:

If I've got this all right, I'm astonished... and a little relieved, at last.

I think you need to go back and re-think all this.

Posted by: Don, Tuesday, August 21, 2007, 10:02pm; Reply: 38
Quoted from Ronagon
2) Are Lewis antigens measured through a blood test?  After all, if they were just measured with a saliva test, how would you be able to distinguish between a+b- and a-b-, when both would presumably still be bound on a non-secreted cell surface?

Here is a page that explains both the secretor saliva and Lewis blood testing procedures: DETERMINING SECRETOR STATUS
Posted by: Lola, Tuesday, August 21, 2007, 10:18pm; Reply: 39
Quoted Text
The way I understand is, it is about whether the ABH antigens being secreted or not, and not about secreting Lewis antigens.

as Yaman also mentioned in the second post of this thread......
Posted by: Don, Tuesday, August 21, 2007, 10:44pm; Reply: 40
Quoted from lola

as Yaman also mentioned in the second post of this thread......

Yes, but Ron kept mentioning Lewis being secreted, so I thought it was worth repeating that secretor status applies to ABH being secreted, not Lewis.

Posted by: Lola, Wednesday, August 22, 2007, 2:46am; Reply: 41
right Don!
Posted by: 841 (Guest), Wednesday, August 22, 2007, 4:44am; Reply: 42
I just received the results for the saliva test.. and  am happy with the secretor result.  I am confused about the suggestion to have confirmatory tests of Lewis blood group types.

I have read through  this thread  but I can't say I am any the wiser  :-/  
Is the saliva test as such  sufficient for me to tailor my diet around it, or are more tests needed?

The Lewis bit is new to me, and for some reason whatever I read about it, it doesn't seem to sink in..  funny sort of brain fog at the moment.

Posted by: Lola, Wednesday, August 22, 2007, 4:51am; Reply: 43
saliva test is quite accurate!
no need to do a blood test.
Posted by: Don, Wednesday, August 22, 2007, 1:22pm; Reply: 44
Quoted from lola
saliva test is quite accurate!
no need to do a blood test.

Agree, but let me just add that there is no reason to do the Lewis blood test unless you are considering doing SWAMI, then you might want to find out if you are Lewis a-b-, since that is an optional input.

Posted by: Don, Wednesday, August 22, 2007, 1:32pm; Reply: 45
Quoted from Hannah2
I just received the results for the saliva test.. and  am happy with the secretor result.  I am confused about the suggestion to have confirmatory tests of Lewis blood group types.

The saliva test is the best way to determine secretor status.
Quoted from Hannah2
I have read through  this thread  but I can't say I am any the wiser  :-/  

I am not surprised. Much of what was posted in this thread was confusing and not necessarily exactly correct information about the Lewis type system.
Quoted from Hannah2
Is the saliva test as such  sufficient for me to tailor my diet around it, or are more tests needed?

The saliva test is sufficient for now. However, for SWAMI you might want to consider some additional testing and once the new Genotype Diet book comes out we may find out that there are additional tests that will help to individualize our diets.
Quoted from Hannah2
The Lewis bit is new to me, and for some reason whatever I read about it, it doesn't seem to sink in..  funny sort of brain fog at the moment.

The wiki articles on the topic are good. If you haven't already, you might want to read them sometime.
Posted by: Ronagon (Guest), Wednesday, August 22, 2007, 1:59pm; Reply: 46
Quoted Text
I am not surprised. Much of what was posted in this thread was confusing and not necessarily exactly correct information about the Lewis type system.


Well, my purpose in starting this thread was to try and figure things out, starting from an openly-declared state of confusion.  I even titled this thread to indicate that.  

I'm not sure how else I'm supposed to learn this stuff without asking questions...  
Posted by: Don, Wednesday, August 22, 2007, 2:14pm; Reply: 47
Most definitely you get lots of points for discussing and trying to make sense of of it!
Posted by: Lola, Wednesday, August 22, 2007, 6:33pm; Reply: 48
Quoted Text
there is no reason to do the Lewis blood test unless you are considering doing SWAMI, then you might want to find out if you are Lewis a-b-, since that is an optional input.


and once that turns up positive, like in my case, then you do want to be double sure with the saliva test, right Don? ;)

still haven t gotten around to it...unbelievable!! :'(

a friend of mine in Barcelona who does allergy testing is now implementing the lewis test in her lab, after I convinced her on the importance of determining secretor status for her patients!!!
but down here, am still looking for a lab to transform. lol
slow wins the race!
I m about to meet some lab colleges of hers here in Mexico city, interested in the lewis test implementation.......it s a process, but well worth it!
Posted by: Don, Wednesday, August 22, 2007, 7:22pm; Reply: 49
Quoted from lola
and once that turns up positive, like in my case, then you do want to be double sure with the saliva test, right Don? ;)

still haven t gotten around to it...unbelievable!! :'(

a friend of mine in Barcelona who does allergy testing is now implementing the lewis test in her lab, after I convinced her on the importance of determining secretor status for her patients!!!
but down here, am still looking for a lab to transform. lol
slow wins the race!
I m about to meet some lab colleges of hers here in Mexico city, interested in the lewis test implementation.......it s a process, but well worth it!

You should have done your spitting at the IfHI conference and shipped it from there, but I guess you didn't know you were a Lewis (a-b-) then and would still needed to confirm your secretor status with the saliva secretor test. :o

Good luck on your work with the labs. After you convince them to do the Lewis test then you can start working on them to do the secretor saliva test too.
Posted by: Lola, Wednesday, August 22, 2007, 7:29pm; Reply: 50
will do!
thanks Don!
too bad SWCNM lab didn t have that option too when we were there.

which article or link would you suggest is the more accurate one to pass along to these people so they understand the science behind the importance of performing the lewis blood test together with the saliva test, too?

in order to get a perfect result....
Posted by: Teresa S, Wednesday, August 22, 2007, 7:54pm; Reply: 51
Lola
I hope your friend could implement de Lewis test in Barcelona, the city where I live.  Is she also a BTD practicioner?
Posted by: Lola, Wednesday, August 22, 2007, 8:27pm; Reply: 52
she specializes in allergy testing and is now trying to learn all she can on BTD from me!
I ll send you a pm with her email address so you can contact her.
Posted by: Lloyd, Wednesday, August 22, 2007, 9:57pm; Reply: 53
Quoted from lola


and once that turns up positive, like in my case,


Some people can turn a negative into a positive.

Lola turns double-negatives into positives!!   ;D

Posted by: Lola, Thursday, August 23, 2007, 12:36am; Reply: 54
;) purely mathematical!
Posted by: Don, Thursday, August 23, 2007, 2:54am; Reply: 55
Quoted from lola
which article or link would you suggest is the more accurate one to pass along to these people so they understand the science behind the importance of performing the lewis blood test together with the saliva test, too?

in order to get a perfect result....

How about these:
http://faculty.matcmadison.edu/mljensen/BloodBank/Lab_Manual/determining_secretor_status.htm

http://www.dadamo.com/knowbase/subtype/subtype2.htm

http://www.dadamo.com/wiki/wiki.pl/Secretor_Status
Posted by: Lola, Thursday, August 23, 2007, 3:45am; Reply: 56
gracias Don!

how are your son s Spanish lessons going?
let him know I can help him anytime, if he needs it, ok?
Posted by: lilith_bcn, Friday, August 15, 2008, 9:34pm; Reply: 57
What SWAMI means? ??)
Posted by: C_Sharp, Saturday, August 16, 2008, 12:45am; Reply: 58
Quoted from lilith_bcn
What SWAMI means? ??)


Swami is a computer program that generates a highly customized diet plan tailored to each individual. This software was written by Dr. Peter D'Adamo. The program perfoms 10 million individual calculations (considers 225 individual nutrient values found in each of 800 foods, matched to the results of of an individuals measurements and values-Blood type, secretor status, and many more) to create your personalized GenoType diet.

The SWAMI GenoType software harnesses the power of computers and artificial intelligence, using their tremendous precision and speed to help tailor unique one-of-a kind diets to individuals, based on their blood types, fingerprints, medical history, biometric measurements and over ninety other variables.

Dr. D and a few select people are using the software now. I believe it will be expanded to all IFHI certified practioners shortly.

In September, you will be able to use an online consumer version of the program without going to health care practitioner.
Posted by: Lola, Saturday, August 16, 2008, 1:58am; Reply: 59
http://www.4yourtype.com/level4.asp
SWAMI = Serotyping With Advanced Modifying Inventories
Posted by: lilith_bcn, Saturday, August 16, 2008, 11:12pm; Reply: 60
Thank you, it's really impressive. :)
Posted by: David, Friday, December 23, 2011, 5:42pm; Reply: 61
I just called a local lab and inquired about the Lewis Type Test. They quoted a price of $34.00 with results within 24-48 hours.
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