81 year olf female admitted for respiratory distress. Phenotypes Le(a-b+). No reactivity detected using LISS tube technique. Using PEG, the only reactivity detected was with five Le(a+) cells. The Le(a+) cells reacted weak to 1+. This reactivity was not abolished by Le substance.

81 year olf female admitted for respiratory distress. Phenotypes Le(a-b+). No reactivity detected using LISS tube technique. Using PEG, the only reactivity detected was with five Le(a+) cells. The Le(a+) cells reacted weak to 1+. This reactivity was not abolished by Le substance.

It could well be, but it could also be one of the compound ABO/Lewis antibodies, although, having said that, those recognised by the ISBT Committee on the terminology of red cell surface antigens are only LebH, ALeb and BLeb, rather than LeaH, ALea or BLea.

If you can, it might just be worth your while trying to get a clotted sample of blood from the patient, enzyme treating some Le(a+) red cells and seeing if you get any haemolysis at various incubation temperatures. Lewis antibodies are pretty good at activating the classical complement pathway.

:idea::idea:

Based on the biochemistry of the Lewis system, Lewis b+ individuals also produce Lewis a (in smaller amounts and not generally detected on the red blood cells), so you would not expect a Lewis b+ individual to be able to produce an anti-Lea. What is the ABO type of the patient?

Based on the biochemistry of the Lewis system, Lewis b+ individuals also produce Lewis a (in smaller amounts and not generally detected on the red blood cells), so you would not expect a Lewis b+ individual to be able to produce an anti-Lea. What is the ABO type of the patient?

I entirely agree with you SMW, but having said that, we've detected three examples in two weeks!!!!!!!!!!!

Based on the biochemistry of the Lewis system, Lewis b+ individuals also produce Lewis a (in smaller amounts and not generally detected on the red blood cells), so you would not expect a Lewis b+ individual to be able to produce an anti-Lea. What is the ABO type of the patient?

The patient is an O Positive.

It could well be, but it could also be one of the compound ABO/Lewis antibodies, although, having said that, those recognised by the ISBT Committee on the terminology of red cell surface antigens are only LebH, ALeb and BLeb, rather than LeaH, ALea or BLea.

If you can, it might just be worth your while trying to get a clotted sample of blood from the patient, enzyme treating some Le(a+) red cells and seeing if you get any haemolysis at various incubation temperatures. Lewis antibodies are pretty good at activating the classical complement pathway.

:idea::idea:

Malcolm, why it can't be neutralized by lea substance?

Att, the substance is not from an O type person?

Edited March 4, 201114 yr by shily

I'm not saying it can't Yanxia - I was, if you like, thinking out loud!!!!!!!

I presume that an anti-ALeb, for example, will recognise an epitope that is only present on group A, Le(a-b+) red cells, which must have something to do with the juxtaposition of the L-fucose and the N-1, 3-acetyl-D-galactosamine molecules, and I was just wondering if the Lewis substance would be able to efficiently inhibit an antibody that recognising this "compound" epitope. I don't know that it can't - I was just wondering.

:surrender:surrender:surrender:surrender:surrender

Malcolm, why it can't be neutralized by lea substance?

Att, the substance is not from an O type person?

The Lewis substance is commercially prepared, Immucor/Gamma. The product insert does not specify an ABO. Under limitations it is noted that anti-H is also neutralized.

The Lewis substance is commercially prepared, Immucor/Gamma. The product insert does not specify an ABO. Under limitations it is noted that anti-H is also neutralized.

I see from where you are coming, but that doesn't necessarily mean that it will inhibit, for example, ALeb. The reason it will inhibit H substance as well as Lewis substance is because both antigens have an L-fucose as the terminal sugar residue.

I'm not saying it can't Yanxia - I was, if you like, thinking out loud!!!!!!!

I presume that an anti-ALeb, for example, will recognise an epitope that is only present on group A, Le(a-b+) red cells, which must have something to do with the juxtaposition of the L-fucose and the N-1, 3-acetyl-D-galactosamine molecules, and I was just wondering if the Lewis substance would be able to efficiently inhibit an antibody that recognising this "compound" epitope. I don't know that it can't - I was just wondering.

:surrender:surrender:surrender:surrender:surrender

Thank you , Malcolm. I think the antibodies reacted with the screen cells , because lot of the screening cells is type O cells, so if it is anti-Lewis, the Lewis substance will neutralize the reaction with screening cells. How do you think about it?

I don't know if I express it clearly, I think if it is anti-Lewis, the antibodies is anti-HLea compound or anti-Lea, if the Lewis substance can also neutralize H antibodies , so it can inhibit the reaction with the screening cells. But it can't ,so I don't think it is anti-Lea.

I am totally agree with Malcolm to enzyme treat the screeing cells and /or incubate in differ temperature and/ or add the serum to cells ratio to see if we can get something more.