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We have received a further sample from this patient but it is now further complicated by the fact she has now been given anti-D prophylaxis. It is a very interesting case and I would have liked to follow it through however I no longer work in the lab. Thank you for all your input.

Just to update on the latest results for this patient. The most recent sample gave a 1+ reaction with the R2R2 cell on the ID panel but was negative with the 2 R1R1 cells cells by IAT and all direct enzyme cells. We also performed an enzyme IAT and got (+) reaction with the 2 R1R1 cells and a 1+ reaction with the R2R2 cell. We are concluding that it is a weak anti-D and we will continue to monitor throughout her pregnancy. It has not yet been quantified in this pregnancy.

Thanks Malcolm That is really helpful . I will get in touch with Alan/Doris for further information .

Our lab is a member of the SCARF scheme but we seem to be receiving less and less rare cells and wondered whether all labs are experiencing this? We currently store rare cells in LN2 but we are being encouraged to reduce our use of LN2 due to the H&S risks. I would be grateful to hear how other sites freeze and store these cells?

Thanks. Much appreciated!

I don't know for sure but there was nothing on her referral suggesting she had received treatment for any medical conditions.

Yes ,the neutral cards do not contain any anti globulin reagents however I thought that if an Rh antibody was present this would be enhanced by the enzyme techniques? The current BCSH guidelines for compatibility testing state that is acceptable to exclude Rh antibodies using validated techniques with enzyme treated cells. That being said, if an antibody was detected by IAT showing Rh specificity I would not exclude its presence even if it was negative by enzyme technique. In this case the reactions were variable but never more than a 2+ reaction, sometimes there in both techniques , and sometimes only by IAT. In the most recent sample, the enzyme is negative and the only reactions by IAT were with an R2R2 in the screening cells and with the R2R2 in the panel. (both 1+ reactions). It is also possible that she has had a prophylactic anti-D injection that has not been documented in her notes. As far as management of the pregnancy is concerned anti-D prophylaxis will be recommended at present.

The test is performed on the IH1000 using a papainised panel and neutral cards.

We have an obstetric patient (3rd pregnancy) who is group O ccdee who has an antibody which shows anti-D specificity however this antibody is only very weakly reactive by IAT and enzyme.Sometimes it is reactive by bothIAT and enzyme however unusually it sometimes reactive by IAT only . This antibody was also present in her second pregnancy. There has been no known administration of anti-D prophylaxis in her current pregnancy. I would be interested to hear your thoughts on this.

Just to update you on the outcome of this case. We tested the plasma against Null cells by IAT and it was negative with an Rh null cell. We sent it for further testing.Our results were reproducible but they got a strong positive result with the enzyme auto (which we don't do) and concluded it was an auto antibody with Rh specificity.

Thanks for your responses and suggestions. In answer to your questions. The cells appear to auto agglutinate using CAT - all wells positive in ABO and Rh cards but typing by tube was fine- no false positive reactions. We used NHSBT adsorption cells which are enzyme treated. We did the adsorption 6 times. We do not have access to chloroquine so can't try removing the auto antibody. The direct testing at RT was done with the neat unadsorbed plasma. The only information I have about the patient is that they have macrocytic anaemia.

We have a female patient- group O R1r (56) who has a high titre antibody. Still 2+ at 1/1024. The reaction by Gel IAT v neat plasma is 4+ with all cells apart from the pvp which is 3+. By LISS tube IAT the reactions are 3+ v the screening cells but the pvp is markedly weaker. The differential IAT shows an IgG coating only. The allo absorbed plasma was completely negative v panel by Gel IAT. A RT direct tube screen gave 2+ reactions with all cellsincluding the pvp and Oi . I am concerend that there may also be an antibody to a high incidence antigen present and would appreciate any thoughts.

Thanks for that. It makes it a bit clearer in my head and happier with the selection of blood. (Sorry about the typo - I realise Oh would need H neg and not I neg ! )

I am trying to get anti -H and anti-HI correct in my head and can't find any good articles on it. I wanted to check. Is it only Bombay phenotype that can produce a true allo anti-H and require I negative blood? In Para Bombay is it only A1, A1B and B that can form a weak reacting anti-H and is it really auto anti-H? For transfusion they would get 37°C IAT compatible and never A2 or O? The same goes for anti-HI. Is it only para Bombays that produce this. Is it really auto or can normal A1,A1B and B individuals produce it too. Is there such a thing as auto ant-H and HI in group O individuals?

Thanks. That's what I thought but as we have always done it thought I should check if there was some reason I was unaware of. It probably dates back to when we used polyclonal reagents that were less reliable.