Has anyone ever encountered a patient that high a High Incident Antibody? If all screen cells are 3+ and all panels cells are 3+ with a negative auto control, would you assume that this is a High Incident Antibody?

What type of antibody screen? Gel, tube; enzyme, AHG? Temperature - RT, 37C? What is the ABO group of the patient?( Don't laugh Malcom, we had 3 Bombay brothers and this is how the one going to OR presented)

What type of antibody screen? Gel, capture, tube, PEG; enzyme, AHG? Temperature - RT, 37C? What is the ABO group of the patient, does the serum typing match the cell typing?( Don't laugh Malcom, we had 3 Bombay brothers and this is how the one going to OR presented). Age of patient, male, female, if female, ever been pregnant?

That would probably be a little strong for an antibody to the reagent cell diluent, but there are false positives such as these sometimes. History, as Michele requests, can be valuable.

Has anyone ever encountered a patient that high a High Incident Antibody? If all screen cells are 3+ and all panels cells are 3+ with a negative auto control, would you assume that this is a High Incident Antibody?

One of the first threads I ever started on this site suggested that I am a pedant - and I still am! What you are really asking is, is this likely to be an antibody directed against a high-incidence antigen, rather than, is this a high-incidence antibody (a very different thing). Anti-Vel, for example, is an antibody directed against a high-incidence antigen, whereas, anti-A, for example, is a high-incidence antibody! Right- rant over!!!!!!!

This certainly sounds like it is an antibody directed against a high-incidence antigen, but, as tricore suggests, we really need a bit more information, so that we know where to go. Of particular interest would be the ethnic origin of the patient, but, that having been said, the first thing to do is to type the patient for C, c, E, e, M, N, S, s, P1, Lu(a), Lu(, K, k, Kp(a), Kp(, Le(a), Le(, Fy(a), Fy(, Jk(a) and Jk(, as well as ABO and D, as these types can often give a clue, but we really do need that other information.

Must be nice to have all those typing sera available, Malcolm!

Must be nice to have all those typing sera available, Malcolm!

Yes, I know Mabel, "easy for me to say"! That having been said, I don't know of any Reference Laboratory, faced with such an antibody problem that would not begin with a full cell type. It really does make a difference knowing this full type before we go on to start using our extremely rare antisera and equally rare reagent red cells.

When I start out by performing a complete phenotype (I think I described this on a Post in Case Studies once ??), I have to admit, I do not type for P1, Lea, Leb, M or N. Not that those could not be there; but rather than I am usually fortunate in coming up with the answer without having to bother with those (may have to rule them out later; but take a chance in my initial analysis).

Then I take that phenotype and find 1 Panel Cell that is Negative for all the patient lacks (so if patient is E-K-Fyb-s- but positive for everything else; I would just look for a cell that is

E-K-Fyb-s-; everything else could be NEG or POS; doesn't matter). If the reaction is Negative, you are likely dealing with Multiples; if Positive, more likely a High Incidence.

But I have also frequently been fortunate in information that just the phenotype provides; i.e. patient may be Jka-Jkb-; then I test for Jk3. Or patient may be S-s-; then I think U; etc.

Just some things to think about...

Thanks,

Brenda Hutson, CLS(ASCP)SBB

Actually, I agree with an awful lot of what you say there Brenda, and we would not necessarily group for M, N and P1, as MkMk is so rare, and P1- are quite common; we just do them for completeness.

We would perform the Lewis typing, on the grounds that so many antibody panels in the UK do not have a cell that is Le(a-b-) - not helpful - and so, sometimes a simple anti-Le(a+ can look like an antibody directed against a high-incidence antigen.

Hey Malcolm,

I keep sending you e-mails; but I think I must be doing something wrong (I can be computer-compromized at times)? Because I would still love to have your input also on my Thread recently submitted on Case Studies....

Thanks,

Brenda

Actually, I agree with an awful lot of what you say there Brenda, and we would not necessarily group for M, N and P1, as MkMk is so rare, and P1- are quite common; we just do them for completeness.

We would perform the Lewis typing, on the grounds that so many antibody panels in the UK do not have a cell that is Le(a-b-) - not helpful - and so, sometimes a simple anti-Le(a+ can look like an antibody directed against a high-incidence antigen.

Yes, I concur. But in part, I was basing that on the 3+ strength of reactivity; not something "I" have seen much with Lewis Antibodies......

Brenda

Actually, I agree with an awful lot of what you say there Brenda, and we would not necessarily group for M, N and P1, as MkMk is so rare, and P1- are quite common; we just do them for completeness.

We would perform the Lewis typing, on the grounds that so many antibody panels in the UK do not have a cell that is Le(a-b-) - not helpful - and so, sometimes a simple anti-Le(a+ can look like an antibody directed against a high-incidence antigen.

I THINK I sent you a private message. Has it not got through? Basically, I'm off sick and will discuss properly when I'm back.

Yes, I concur. But in part, I was basing that on the 3+ strength of reactivity; not something "I" have seen much with Lewis Antibodies......

Brenda

Well, again, I agree, but on the other hand, anti-Le(a+ can look an awful lot like an anti-CR1-related specificity, such as anti-Kna, reacting 1+ with enzyme-treated and untreated panel cells, so I still think it worthwhile to perform Lewis typing in such circumstances, and, as I say, we tend to do such typing on all occasions, just so we know where we are going.

Of course it would not be a Bombay if compatible with O neg.

One of the first threads I ever started on this site suggested that I am a pedant - and I still am! What you are really asking is, is this likely to be an antibody directed against a high-incidence antigen, rather than, is this a high-incidence antibody (a very different thing). Anti-Vel, for example, is an antibody directed against a high-incidence antigen, whereas, anti-A, for example, is a high-incidence antibody! Right- rant over!!!!!!!

Congratulations Malcolm! I wondered how long it would be before someone would step into John Judd's shoes and attempt to keep us on the grammatical straight and narrow. Keep up the good work.

Congratulations Malcolm! I wondered how long it would be before someone would step into John Judd's shoes and attempt to keep us on the grammatical straight and narrow. Keep up the good work.

Thanks John - that is one heck of a compliment - but I wouldn't presume to put myself in a league anywhere near the Prof!

Ok, so now you are using "big words;" I will concede!

Brenda

Well, again, I agree, but on the other hand, anti-Le(a+ can look an awful lot like an anti-CR1-related specificity, such as anti-Kna, reacting 1+ with enzyme-treated and untreated panel cells, so I still think it worthwhile to perform Lewis typing in such circumstances, and, as I say, we tend to do such typing on all occasions, just so we know where we are going.

All CR1 is, is the complement receptor 1 molecule on which all of the antigens of the Knops Blood Group System are expressed. Many of these are of high-incidence, but tend to give weak 1+ type reactions with their corresponding antibodies.