mrmic

Sooooooo.........is is 1 positive reactive cell out of 3 selected cells ok? What next? Do you keep testing "homozygous or heterozygous" selected antigen positive cells til you get 3 negative? It's not just rulling out, it's looking for what's in. It is a good thing to have a Immunohematology Reference Lab partner to assist with multiple antibodies or antibodies to antigens of high frequency. Your blood supplier should have this service for you... Probability calculations do not always go hand to hand with antigen expression. 🐀 mic

😁 Something I remember!! Back in the "Reference" lab days when we could innovate on our feet without reimbursement issues, and probably some safety issues too. Malcolm, if I may address you informally, if not pardon me,. we did the same process as you described except, we found an old incubator we could adjust the temp and put our serofuge inside to centrifuge, running the plug wire up through the hole of the incubator that normally would have a black rubber stopper holding a glass thermometer! Good story, thanks for the memory. 🐀 mic

Still old school........why..........because I'm old.............. Is RBC genotyping our future? But first.............. Has research revealed if the extent of RBC antigen polymorphism higher than previously known by the number of antigen specificities? Are there serologically indistinguishable variants or subtypes identified, and if these variants are different from the wild type only by a very few amino acid substitutions, can these be functionally distinct and relevant in genotype matching for transfusion and hematopoietic stem cell transplantation? Which are clinically significant for transfusion purposes or hematopoietic stem cell transplantation or GVHD? These are similar issues that the HLA transplantation field has been discussing. Are blood bankers (Immunohematology field) today also discussing similar issues at regional and national meetings? I may be off track and need to get back involved with meeting to get "re-educated" and how far we have progressed over the last 20 years.

Gel testing is just a "miniature" tube system using a "controlled" % cell suspension and a Low ionic environment. Although the tube test can be similar, unless you are using the same %, concentrations and ratio, you might find it difficult to compare in-vitro results. Although the sensitivity may be slightly increased for some antigen-antibody reactivity, maybe those we don't want to see, it also has similar problems as other low-ionic methods with the Kell system. I agree with Ms. Adams comments. It is important that the OB/GYNs know how you are performing the titrations and if the method(s) correlates with clinical outcomes. This has been established with the tube method, maybe the tile as well, but I am not aware of references for the "gel" method. I believe, as long as the OB/GYN is aware that the "trigger" titer number for clinical intervention may be different for the gel method, however, the monitoring during pregnancy looking for a significant change in titer may be consistent with both methods. I also agree that use of other clinical data (Doppler etc.) is becoming a better standard of practice than amniocentesis and it is less risky for the mother and child. Although in suspected severe cases of HDN, amniocentesis may still be warranted. Better have your validations and IQCP ready...

Just a thought, Has the donor center been contacted to review the Donor's history? Meds,(prescrip or herbal), donor not feeling well in the past, or afterwards of the donation? Could they test the donor's plasma/serum against other antigens of low frequency? They should have extra or could call the donor in. Patient may be reacting to something specific with the donor's donation. Patient has allergies to something the donor is taking (meds or etc). Could be a cytotoxin from some bacterial exposure the donor has had. Once we had a case with a snake handler, donor had or has had Salmonella but felt fine at the time of donation, and the toxins were present in the platelets' plasma..... similar reaction. (no positive DAT though). I agree with previous response from Mr. Needs, that DAT and eluate specificity could be co-incidental, especially since he has been multi-transfused and may not be related to the immediate "transfusion reaction". Interesting case! Thanks for sharing....

ABO antigens are basically sugars structures. The development and expression of these antigens and antibodies are controlled by various genes an individual inherits. The antibodies are also possibly produced based on the various "natural" exposures to similar antigens in the environment, gut, etc. and the immune system functionality of the antibody producer. (or in the case of commercial antisera, the particular antibody producer(s) or cell line(s) used to produce the antibody can vary from manufacturer to manufacturer). Actually, as I ponder this, maybe all antigens/antibodies are effected by some of the same processes...... Therefore, in my humble opinion, the strengths of the agglutination reaction within in any one test method, maybe affected by these factors as well as the method itself. If everyone was group O it would be nice for Blood Bank ................. but what's the adventure in that? Variety is the spice of life!

If no immediate reaction, maybe nothing will happen. Shorten red cell survival? Watch kidney function. Just lucky I guess................. don't do it again........... who knows.......... There have been many cases of patients getting the wrong blood type with no reactions and no clinically ill effects. A lot of factors are in play that we still do not have a good answer for. In xenotransfusions, the "anti-species" antigen-antibody reaction is quite strong and causes clinically important issues, much more so than ABO. However, can be suppressed to some extent with high does of corresponding sugar...... Be sure to post to let us know what the post-transfusion outcome......... Thanks for the question/topic...

sugar sugar

Can you provide the information stated in MIC.19840 ?

Along with this topic. Could you issue multiple units for multiple patients to the nurse/courier picking up the blood from the transfusion service? It appears if you issue prior to the person being there to pick it up, you could do this... It seems to me that the practice of only dispensing 1 unit for 1 patient at the transfusion service window is a pretty standard policy (exempt massives, emergencies, etc). However, I could not find any Standard that indicated the 1 for 1 was a requirement.....

I am curious to find out what methods other Microbiology Labs are using for investigating Transfusion Reactions for the Blood Bank Transfusion Service? Limited verbal communications suggest there are a lot of variations out there. Based on product, how do you screen for Salmonella, etc., Staph aureus, Yeast or Yersinia? Currently, the ways its has been handed down for X years, is that we inoculate three Thio broth tubes and incubate them at 4C, 22C, and 35-37C for 5 days. If there is any growth we, gram stain and sub to appropriate media plates. I am a little concerned if this is still adequate, esp for Yersinia spp. What does your Blood Bank Transfusion Service "think" you are screening for? Thanks

History History History pregnancies, transfusions, daddies, medications, High BP? Early autoantibody, early autoantibody mimicking anti-D? One pathologist I have worked with considered pregnancy a disease, you may have some non-red cell stimulated mimicking antibody specificities due to a hyped up immune system. We have seen an Anti-K titer rise during the pregnancy only to find the subsequent child and daddy to be Kell negative. Would be nice to be able to follow patient, antibody detections, titers, Rh-hr typing of infant, etc................... make a good abstract case presentation at a meeting.....

If I remember from many moons ago, there was a reference paper indicating the optimal time for antibody-antigen complexes in saline was 60 minutes. I believe there were subsequent papers/abstracts suggesting that shorter incubation times using saline and "pre-warm" methods allo-antibodies were being missed, however, the warm reactive autoantibody was not interfering and the crossmatches were "compatible". Hence, once allo-antibodies are ruled out through other immunohematological testing methods, issuing "least incompatible" crossmatches are ok as well thereby reflecting what is really happening.

Warm autos are a curious bunch. Are antibodies present truly auto or are the allo? Are they really allo or mimicking specificities of the autoantibody(ies) present. Once you start transfusions you should be doing allo-absorptions since transfused red cells may be present. Do multiple adsorptions have a dillutional effect with the absorbed serum which may cause a weak significant allo antibody be missed? Maybe the crossmatch is of little use in these situations so whatever you do is ok? In these situations the focus is on the cause and resolution of the warm autoantibody production by the patient and the determination of the benefits/risks of transfusion. We had seen little differences with utilizing "absorbed" sera crossmatchs vs "least incompatible" crossmatches with regards to patient outcome. However, it is a technically challenging/interesting when we get these cases sent to us and then to try to follow up of the patients as long as we can.