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The antibodies we have had difficulty detecting, when taken back to Gel technique and Tube technique- showed good reactivity.

Thank you for that- and I agree there will always be differences in detection techniques. A lot of my concerns surround repeatability using the same testing system. When you see anti-K, anti-S, anti-Fya - not being detected in a reproducible way- with the same sample- worries do set in, and ultimately in a highly litigious society who would take responsibility if the patient had a TR ? Also when less sensitive (tube) techniques were used for primary antibody screening- for us this was approx 10 years ago, we all accepted that we would see approx 2-3 DTRs / year caused by sub-detectable antibodies- it was not unusual. With the advent of newer techniques - this frequency was reduced significantly. When users change their primary identification techniques- there needs to be a level of confidence that the test is better than what was previously used (especially as these systems allowed us to progress to electronic issue), and that we are not going to see an increase in transfusion reactions to the level we had 10 yrs ago. Obviously only time will tell if any one technique has a greater association with DTRs, but this also relies on staff reporting adverse reactions appropriately. Our respective haemovigilance bodies need to collate and trend this data carefully with respect to different serological techniques used. I fully agree that the numbers of patients we are talking about is few (hopefully !!) - but we all do need to question why we are even having this discussion. Best Wishes Rashmi

Hi Cornelia, I don't know much about the Tango - does this use liquid screening cells that are adhered to microplates or is the microplate pre-coated as for the capture screen? Thanks Rashmi

Hi Linda, This methodology seems to require a lot of staff training- and in your situation you can afford to investigate thoroughly all results obtained by your staff. This is not realistic in a trauma care setting- when decisions have to be made quickly. Also in the case of obstetrics and urgent unplanned procedures. Antibody screening and identification must be simple to perform and interpret for 99% cases - especially as staff at my place are lone workers at night and need to make these decisions (they are also mainly haematology folk- with basic transfusion serology experience). As staffing becomes increasingly multidisciplinary the need for simplicity is even more important, to maintain patient safety. Best Wishes Rashmi

Thanks Linda, -that does clarify things. Do your trainee staff find interpreting reactions easy- or are only your experienced staff let loose on the equipment ? and are you comparing the results against the computer screen or from the printout ( we are only allowed to print using black and white toners- the image is quite poor). Best wishes Rashmi

Thanks for the info...so you had a problem with one of the antigen positive crossmatches- was the reaction '?' or negative?- What if one of your techs had inadvertantly issued this unit ? - who would the responsibility lie with if the patient had a TR ? Thanks Rashmi

Thanks- but Gel techniques also use monospecific anti-IgG reagents- so why would an antibody be detected by Gel and not by Capture ? - what is it about capture that makes it more specific. I have also been told that Capture may not detect certain IgG subclasses of antibodies (IgG2and IgG4)- so does this mean the indicator cells are coated only in IgG1and IgG3? - so would we all be happy to transfuse a patient with an anti-Fya or -K that was detrermined to be an IgG2 or4 subclass ?-I certainly would not be, and would consider this unsafe practice. Also could the detection be a feature of adhering the red cell stroma to the wells ? Thanks Rashmi

Has anybody noticed problems with the reproducibility of screen results using automated Gel or automated solid phase techniques ( solidscreen or capture ) I am especially interested in cases where the sample (from patient's that have known antibodies) test as screen negative, then when the SAME sample is re-tested- a positive/ different interpretation is given. I would also like to hear from users of the above techniques- as to the ease of identifying antibodies using the various methodologies and manufacturers identification panels. Many thanks Rashmi rashmirook@hotmail.com

If anyone runs their ECHO 24hrs/ day- even for small number of samples- please could you tell me how often you change your ABO grouping reagents, if you leave them onboard the analyser all the time? Thanks Rashmi

I'm trying to develop a better understanding of Capture, please could someone actually explain how the Capture screen manages to avoid detecting these 'insignificant IgM antibodies'. Is this specifically a feature of the Capture-R strips, the incubation of the plate or the AHG reagent used? Also, if anyone uses this techniques to perform donor/ patient compatibility testing- how does this reduced ability to detect IgM antibodies ensure that ABO incompatibilities are not missed ?....may be i'm just getting a bit confused ??!!! Many thanks Rashmi

Hi Jeff, It would be a good idea to freeze some aliquots and run them with the subsequent lot of capture plates for next few months. Run this at the start of a new lot and close to lot expiry date.

Hi Jeff, Could you try and see if you can detect the anti-K by Tube technique?- this data would be very useful for me. I have had quite a few problems similar to yours and have subsequently reported them to my Medical devices body (MHRA in the UK, who are now investigating). Whenever we change techniques, the detection of clinically significant antibodies MUST be as good as, or better than first generation techniques (tube) and good as or better than second generation techniques (gel), to ensure patient safety. Rashmi

Hi Folks, If you google; BCSH Guidelines- there are lots of UK transfusion guidelines that would help. Information below is from thecompatibility testing one. Evidence from SHOT (Love et al., 2002) with respect to delayed transfusion reactions has been influential in providing evidence for timing of new samples when a transfusion has been given more than 72 h earlier: Patient transfused ............Sample to be taken within 3–14 days .............................. 24 h before transfusion 15–28 days............................. 72 h before transfusion 29 days to 3 months............ 1 week before transfusion Hope this is of use Regards Rashmi

What would be really worrying however....is to have a negative or weak reaction by Capture- that works quite strongly by tube IAT.

I would be really interested to hear from anybody about missed antibodies using Capture-R, especially if your previous testing was by Gel technique. My lab acquired this automation In Jan 2008, and are due to re-validate the system- due to on-going concerns. If anyone has a validation protocol as well- that would be really appreciated. Please feel free to contact me via this site or by email : rashmirook@hotmail.com. Many thanks! Rashmi