Time out

Labgirl, are you referring to a 37C tube IAT, with red cells suspended in saline, with a 30 minute incubation, that gives a 'negative' result?

I would also lean toward A(sub)B (assuming the donor is otherwise healthy) with this one. Although, weak reaction with both A1 and A2 cells seems a little odd. I would have expecetd a stronger reaction with A1 cells, when A2 cells are reactive.

What technique are you using?

cisAB? Seems to fit Issitts description (most appear A2, etc).

Any recent IVIg treatment?

I'd do an auto against ficin treated patients cells. A positive results could be due due auto-anti-D but I think it would more likely represent an 'enzyme auto', as there's a reasonable chance the anti-D is 'allo'. Either interpretation would be 'OK' as both mean 'select' D- blood for xmatch, which is probably what you'd do anyway. A negative result would put you back in the 'what is it?' situation.

What are the 'full' D type results? Do you use ficin treated cells in your auto?

the apocrypha is; if you place a frog in boiling water it will just jump out but if you put it in tepid water and slowly turn up the heat the frog will stay put even up to boiling

My thoughts are; if the unts given 4 weeks ago were 'random' Rh phenotypes, then all will (almost certainly) have been e positive (and have a good chance of being f positive, and slightly less so of being C positive). The circulating residue would give phenotyping results that are difficult to interpret, promote an (allo) immune response, and give ambiguous auto/DAT results (patricularly if the technique of auto and DAT vary a little). So I'm till clutching at straws for my 'boring' answer!

Mabel, do you have the Rh phenotypes of the units given 4 weeks ago?

Not putting down your thoughts John; just posing a sort of question.

Never thought I was being put down, Malcom, just my 'idle musings'! Trying to interpret 'weak stuff' is always a bit of 'hit and miss' job!

Just trying to pose a 'simpler' hypothesis. Would be good to know what was the matter with the patient.

How about something more boring;

1) Rh/JK typing results not valid because of recent transfusion

2) Patient is R2R2, not R1R2

3) Antibodies detecetd (anti-f +/- anti-e +/- anti-C) are weak alloantibodies

4) Auto/DAT results are 'inconclusive' because only the residual cells fron 4 weeks ago have antibody coating them

5) Delayed-type 'transfusion reaction' is occuring (but not clinically significant)

Were the PEG and enzyme adsorptions performed sequentially on the same sample? We've had cases that needed both to remove the autoantibody, i.e., the patient's plasma had an antibody mix that included components that did and did not react with enzyme treated cells.

What type of test was the D type? Has the patient got a positive DAT?

The IgG, IgA, etc., card is , indeed, the one I was referring to. We sometimes see the phenomenon where a pos auto, with a neg DAT, will give a positive resut (usually with the IgG reagent) if you do what I described.

If you get a pos auto but a neg DAT, in gel, you could try this; add patient cells to all wells of a 'monospec' card then add patient plasma to all wells and treat as an IAT (incubate, etc), see what happens

I was just making a general point, that this particular example highlighted - that there are other things to think about. I know some antibodies, that you'd expect to be detected by 'enzymes' (the cited anti-E, for example), may not react as you'd like, but they're not common enough to make us doubt our 'enzyme' panels, I hope (which is why they get published, I guess - who wants to read about ant-E that was detected by 'enzymes'!). Hooves and zebras, as is oft quoted here...

Also, exclusion don't 'stand alone', so, in this example, if the patient was E+ and/ or an enzyme panel was 'negative' would you still 'exclude' anti-E?

So, we've got the hypothetical, familial, Rh phenotypes but what were/are the actual phenotypes?

I'll try again! What's the Rh pehenotype of baby and mother (and father, if you have it)?

My post was not suitable

Also; what is her ABO/D type (and any other red cell phenotypes you might have), what was her Hb at previous discharge, are there any 'haptoglobin' results, is there any thought of a single chronic condition/disease?

Try this link, as a start (clogs are named);

http://www.labmanager.com/?articles.view/articleNo/1133/article/Appropriate-Footwear-in-the-Lab

It looks like a Canadian site, but might be a useful starting point (if only to show the regulation is a Canadian one)

Take a look at this, too;

http://www.bbts.org.uk/PDFs/events/D%20Bruce%20Antenatal%20monitoring%20of%20anti-D%20and%20c.pdf

Also, I'm sure the AABB technical manual does give information on 'titre scores' (I don't have a copy to hand, so can't be more specific), maybe you could try another look?