Colin Barber

Marina I bought a MacBook Pro last December and wish I had gone over to the enlightened years ago. Mac's are expensive but take it from me you won't regret it, so please ignor all the window's posts.

Lara sorry to hear about your patient with the Jka and I do agree that the senario Malcolm describes may happen and is a potential danger for any patient admitted to hospital. I go back to the original post, where a history was know and the current screen is negative so the real question I think we are being asked is do you treat this patient differently. So I think the thing you need to concider about is this patient is, are they at any more risk of producing an antibody as a secondary or amnestic response than any other patient since the current sample was drawn. Where there is a history of an antibody you should always select antigen negative blood whether the antibody is detectable or not so what is the risk that after selecting and crossmatching blood there will be a delayed haemolytic transfusion reaction due to a non-detectable antibody in your current sample. So I stick to my original post this sample has the same validity as any other sample, so if like Liz you have a maximum of 72 hours this sample has 72 hours. I would crossmatching antigen negative units and then apply the BCSH table I posted earlier to decide when we needed a new sample. This thread has prompted some interesting debate about sample validity in general despite a fairly specific question being posted.

This thread seems to have moved away from the original question, which to summerise was in a patient who's historical antibody is not currently detected and with NO recent immune stimulation - ? How long can you use the current sample. A very real situation we, I am sure, all see in from time to time in transfusion labs. My feeling is if the antibody is genuinely sub detectable and there has not been a recent immunizing event, then sample has the same validity period as any sample in your organisation and will depend how you store the plasma/serum prior to a compatibility test. The 3 day rule kicks in once this patient has been transfused (with antigen negative blood I hope), this is someone with a previous history of transfusions they may mount a secondary immune response and a "new" specificity may appear as a result of this transfusion. Therefore making the current sample invalid. I hope this post helps answer the original question.

The 72 hour validity rule I would have thought is based on transfusion history and aimed at secondary immune response following transfusion. In the UK our BCSH guidelines have a table which for those of you familiar with soccer I call the off-side rule, its as convoluted to understand as off-side. But I understand the new guidelines are going to simplify to a sample being valid for 72 hours following Transfusion. I have attached our current off side rule as I call it. [ATTACH]417[/ATTACH] BCSH sample validity.docx

As another UK based BBT member I echo Tonyd's comments and would add I want to know who has had prophylactic anti-D to help with deciding is it prophylactic or immune anti-D when you find anti-D in the antibody screen in a pregnant or recently delivered patient. Therefore I want to stock and issue from the Blood Transfusion department so we have control over who gets it and the records are on the lab computer system.

The 30 minute rule has been a subject of much discussion since the introduction of the Blood Quality and Saftey Regulations and the following clarification was given on www.transfusionguidelines.org.uk Clarification on the "30 minute rule" and reports to SABRE There has been some uncertainty regarding the requirement for SAE reports which involve units out of cold chain storage. The "30 minute rule" is the customary limit accepted in the UK as the time allowed out of controlled storage, which if not exceeded, can allow the unit to be replaced back into controlled storage for re-use. See Joint UKBTS/NIBSC Professional Advisory Committee- Deviations from. 4C temperature storage for red cells: effect on viability and bacterial growth, February 2005 Scenario 1: Unit taken to ward, decision made not to transfuse and unit returned to the issue fridge. The unit has been out of controlled storage for 45 minutes and is replaced into the issue fridge for re-use. As the time out of controlled storage is greater than 30 minutes, the pack should not be returned to the fridge and this should be reported as an SAE. Scenario 2: Unit of red blood cells taken from controlled storage but transfusion not started within 30 minutes. However, clinical decision taken to proceed and unit subsequently transfused within 4 hours of removal from controlled storage. Handbook of Transfusion Medicine (4th edition) states: Administration Use blood administration set; complete the infusion within four hours of removal from controlled temperature storage (see Table 2) This is not reportable as an SAE Scenario 3: Unit taken from controlled storage, transfusion started within 30 minutes but not completed until more than 4hours after removal from controlled storage This is not reportable to MHRA as an SAE, as it is a 'clinical' error outwith the remit of the BSQR A hospital may raise a local incident report due to breach of a local guideline (e.g. where a limit is specified between removal of blood from controlled storage and time of commencing transfusion). This is acceptable, however national guidance (BCSH Handbook) is that transfusion must be 'started as soon as possible and completed within 4 hours of removal from storage'.

Is it possible that the A transferase produced by this lady is also adding a small amount of the B determinant sugar hence the presence of B antigen demonstrated by absorption and elution studies.

From the 2003 BCSH Platelet guidelines: 2. RhD incompatibility • RhD-negative platelet concentrates should be given, where possible, to RhD-negative patients, particularly to women who have not reached the menopause (grade B recommendation, level III evidence). • If RhD-positive platelets are transfused to a RhD-negative woman of childbearing potential, it is recommended that anti-D should be given (grade B recommendation, level III evidence). A dose of 250 i.u. anti-D should be sufficient to cover five adult therapeutic doses of RhD-positive platelets within a 6-week period, and it should be given subcuta- neously in thrombocytopenic patients. • It is not necessary to administer anti-D to RhD-negative men or women without childbearing potential who have haematological disorders and receive platelet concen- trates from donors who are RhD positive.

I sent a sample from one of sickle patients to our Reference lab and when we phoned for a provisional report, the answer was "oh it's just sickle crap". So I now know that is an excepted serological term.

As a long time Galileo user I have seen this type of antibody by capture R IAT quite a few times and I agree with Malcolm posts on the antibody. My feeling is that they are not likely to cause a shortened red cell survival, so are not clinically significant from a transfusion point of view. They are like enzyme only "non-specific" antibodies, I think they are directed against a part of the red cell membrane exposed in production of Capture screening strips, therefore not what is normally recognised as a blood group antigen. In practice we check these patient's plasma against a Capture ID panel and DiaMed gel enzyme and IAT panels. If the antibody is Capture only we concider that the patient does not have significant red cell antibodies and we essentially ignore these Capture only antibodies. As far as I am aware this has not led to a delayed haemolytic transfusion reaction.

Liz, Sorry I assumed you were based in the USA, I have checked with Helen, my wife, and unless there is software update not currently available in the UK Gel stations don't support random access, I did see this demonstrated on the IH1000 at the BBTS trade show last year. We would interested to hear if random access is genuinely available to you on a Gel station as there will a rush for UK users to get this version of the software. Let me know how you get on. Best wishes, Colin

Liz, I have checked again with my wife and unless there is a software update only available in the US the Gel station don't support random access - the IH1000 is claimed to. We would be interested to know if random access is available in the US - so let me know what they say when you check on this. Best wishes, Colin

Liz, Sorry I may have misled you, we use DiaMed for manual backup to the full automation on the Immucor Galileo so we don't have Gel stations - the reason we did not choose Gel Stations were they did not offer random access and you have to wait for the group and the screen to be complete before you get any results and for our work load we would have need 5 machines across our 2 sites. At the London Hospital we are a major trauma centre so getting an automated group securely transferred to our LIMS even before the screen is done is important - we can move to group specific blood and the correct group of FFP quickly. As we get a lot of major trauma I not keen on manual urgent blood groups as the risk of human error under pressure situations is high. My wife has used the Gel station in her hospital for a long time and although she is happy with the machines the lack of random access and waiting for all the work for a batch to be complete before any results are available are the things she would like to see improved. Which I am told is the case with the new DiaMed IH1000, which I saw at the BBTS conference last year and on the stand it looked like it may now be more of a competitor for the Galileo or the new Neo. There is one thing with DiaMed which is an issue for those of us in the UK that do electronic issue (computer crossmatch) their machines don't do "double dip" for blood groups, so for new patients where we do 2 groups to confirm the group the BCSH guidelines say the 2 groups should be from 2 different cell suspensions ie the machine needs to make a separate suspension for each group not do 2 groups from a primary suspension. So to be compliant in the UK you would have to run the 2 groups in different batches so it samples the collection tube twice. This might not be an issue for in the US - do you do electronic issue ? Anyway good luck with the procurement of your analysers. Colin

I have used the Galileo at Barts & The London in the UK since 2003 and as Kate says the Neo is the mark 2 Galileo and I would also quite like to replace our Galileo's with the Neo. Yes they are large through put machines, we have 2 at The London and 1 at Barts, one of the key things for me is fact you can keep adding samples. You don't have to wait for a run to finish before adding more samples.

I have used the Immucor Galileo's since 2003 at Barts & The Royal London in the UK and they have proved to be on the whole good work horses. We have 2 at the London and 1 at Barts they are on a bi-directional interface with our LIMS, which allows us to issue most of red cell via computer crossmatch. The machines are run 24 hours a day and we trickle feed the samples onto the analysers, so G&S samples are run as soon as possible after receipt in the lab. This give confidence to clinicians that for most patient blood can be made available quickly if it is needed. The DiaMed analysers are good machines, but for our work load and desire to continually process (i.e. you don't have to wait for the run to finish to add samples) means the Galileo works better for us

I have a Galileo which uses similar technology to the Echo and we have been doing our cord DAT's on this machine since 2003 without any problems - I wish Immucor would come up with a method for Adult DAT's on the Echo/Galileo/Neo.