I was just wondering why is important to test for little c antigen on all donor units before issuing the units to a patient who has Anti-E.

Does anybody else do this? Thank you for your time

I was just wondering why is important to test for little c antigen on all donor units before issuing the units to a patient who has Anti-E.

Does anybody else do this? Thank you for your time

In the UK, all units are issued with a C, c, D, E and e type, so you would know this "from the word go".

If this were not so, I would have thought it cheaper to group the patient for c, rather than screen the units. If the recipient, who has anti-E, is c+, and there are an awful lot of R1r individuals in the world, then you wouldn't need to screen the units for the c antigen.

:):)

We will type any patient with an Anti - E for little c, for future antibody workups, but we don't issue little c negative units if the patient is c negative.

We will type any patient with an Anti - E for little c, for future antibody workups, but we don't issue little c negative units if the patient is c negative.

We would if the patient were a female of child bearing potential, is, or is likely to become transfusion dependent, or is <18 (abritary age), but otherwise would not.

We do not .

if the patient has Anti-Big E, we will antigent type them for little c. if they are little c positive, then you only worry about giving Big E antigen negative blood. if they are little c neg, we will transfuse both Big E & little c neg units. hope this helps.

We do what gshickman does.

The Technical Manual (16th ed) says: "Some Rh antibodies are often found together. For example, a DCe/DCe (R1R1) patient with anti-E most certainly has been exposed to the c antigen as well. Anti-c may be present in addition to anti-E but may be weak and undetectable at the time of testing. Transfusion of seemingly compatible E-negative blood will most likely be c-positive and may elicit an immediate or a delayed transfusion reaction; therefore, some advocate the avoidance of c-positive blood in this situation." That's the rationale for those of us who do it this way.

Like Malcolm said, I would think it more worthwile to test the patient for c antigen first, since most people will be c positive.

I guess the line of thinking is that c and E are equally immunogenic, and if a patient has formed anti-E they are certainly capable of forming anti-c. Since a transfusion recipient is very likely to encounter c antigen, you would want to limit his or her exposure if it's already been shown they are likely to develop the antibody.

We do type for the c antigen when possible, however in cases where the patient has been recently transfused or is pregnant, then we transfuse c negative red cells in the presence of anti-E. If we get the chance to type them for c antigen down the road, we do it so we can stop providing unneccesary c neg units. It seems like most of our anti-E patients are frequent flyers.

I think that what we are all tending to forget, including me, is that many examples of anti-E, particularly the very weak examples are either, in reality, either anti-E-like antibodies, or are T-cell-Independently produced isoantibodies, rather along the same lines as IgM ABO antibodies.

Therefore, even when the patient is R1R1, they are not necessarily going to produce an anti-c "at the drop of a hat". That having been said, it is impossible to know whether or not we are looking at a genuine immune anti-E, or one of the above.

Personally, and it can only be a personal view-point, given that anti-c can cause both clinically significant HDN, and sometimes HDF, and can cause pretty serious transfusion reactions, I would be loathe to give c+ blood to a person who already has an "anti-E", if they were c negative, except in circumstances I have outlined above.

That, however, is only my opinion, and others may differ with well-reasoned arguments that I cannot go against.

:confused::confused:

We also type for c when the patient has anti-E. If the patient is c negative we give c negative units. We have had 3 patients in the last year where the patient had anti-E and the tech did not type the patient for c or screen the units for c and the patient later developed anti-c because they got transfused c positive units. (delayed reaction)

Shaundrey - A few questions:

1. Was it the same tech in all 3 cases who did not follow your policy of typing the pt for the c antigen?

2. Are you saying that in the last year you had a total of 3 cases where the tech did not type for the c antgen? (And all 3 patients developed anti-c?)

3. Did those 3 patients simply developed Anti-c, or did they actually have delayed transfusion reactions?

Thanks!

Same here- we type patient for c first. If negative, we only transfuse E & c negative units. (We did not do this at the hospital I worked at previously.)

Back in my blood bank days we did not antigen type either the patient or the units for "c" just because the patient had an anti E.

For those of you who do antigen type the patient for c and not the units when the patient is c neg. why are you bothering typing the patient?

:confused:

We do not type units for little c if the patient has anti-E. It is not policy to type the patient for little c, but I usually have it done (along with the rest of the phenotype) if the patient is likely to be a frequent flier. I do this because it may be our last chance to know what the patient can develop in the future. This is, of course, outside of the sickle population who get complete phenotyping on first visit and match phenotype for Rh, Kell, and Duffy.

Back in my blood bank days we did not antigen type either the patient or the units for "c" just because the patient had an anti E.

For those of you who do antigen type the patient for c and not the units when the patient is c neg. why are you bothering typing the patient?

:confused:

I agree John; it does seem a bit daft, but we "fully" Rh type (C, c, D, E, e) and K type all of our referrals the first time we see them (and, come to that, k type them, if they are K+), but for those patients who are either very elderly, who are male (>18, who, of course, will not become pregnant - and if they do, I'm going to be their manager) or who are unlikely to become transfusion-dependent (say, they are having a "one-off" surgical procedure), we (sort of) don't care if they make anti-c, but it's nice to know that they can, if they come in again for antibody identification. We tend to reserve the R1R1 units for those that do not fall into the above categories.

In a way, I suppose we do the C, c, D, E and e typing in the UK because the patient does not have to pay for it directly, or through private insurance (National Insurance pays for it), but it does often prove to be useful knowledge.

When we encounter a patient with Anti-E we do not usually type the patient for the c antigen (unless we have some reason to suspect that the patient may also have Anti-c.)

L106,

1) It was not the same tech each time. It happened with 3 different techs.

2) Yes, 3 cases total where each patient developed anti-c.

3) These were all delayed reactions because each patient was transfused and within 14days (one within 3 days) presented again with a positive screen, stronger than before, and they received units that were positive for the c antigen.

I know it may seem like over kill to give c negative when they haven't developed the antibody but when you have a high population of sickle patients like we do and many of them respond and make antibodies, we feel it is best to minimize the exposure as much as possible. Unfortunately, they also hospital hop and it becomes hard to manage them so you do the best you can.

Shaundrey -

Thanks for responding to my questions. I agree with you......you need to do what seems to be the best for the patient population that you serve.

Donna

L106,

3) These were all delayed reactions because each patient was transfused and within 14days (one within 3 days) presented again with a positive screen, stronger than before, and they received units that were positive for the c antigen.

Sorry to be a nuisance (wanting more information), but were these patient's samples tested with enzyme-treated red cells prior to transfusion, or just by untreated red cells by IAT?

14 days seems quite quick for the development of a completely de novo antibody, let alone 3 days.

I suspect that these patients may already have been immunized at a low level.

:confused::confused:

We will transfuse the c neg with anti-E patient with c neg E neg cells , because most of the anti-E will accompany anti-Ec or anti-c , the anti-c is very will IAT can't detect but will detect use enzym technique.

I think Shaundrey describe is secondary immune

If they have formed Anti-E, then most probably they have been exposed to c, so you should also type for c to determine what type of units you need as you may need to set R1R1 to prevent them from forming Anti-c.

Some 20 years ago the Tech Manual said you should give c neg units to c neg patients with anti-E; then the next edition or so said only that some people recommended this. After awhile I decided to think about it in terms of my patient population and this is what I concluded: both hospitals I have worked in have been bigger hospitals but still in rural, isolated areas out west surrounded by smaller hospitals that don't do antibody IDs. I decided that for us giving c neg units seemed like a reasonable policy so that it preserved our ability to give Rh neg units in an emergency knowing they will almost certainly be E neg and we have at least kept the anti-c titer low enough (i.e. undetectable) that a frank transfusion reaction would not be likely. Not sure if it is right, but that is my logic.