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snance

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snance last won the day on January 27

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    Immunohematologist

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  1. Has the presence of anti-Sda and anti-Lub been ruled out? Both have been reported to show mixed field reactivity and both can be reactive at room temperature. Microscopic exam of reactivity in any phase would help rule out anti-Sda, and since your said it did not look like rouleaux, can it be assumed that it also did not look like an anti-Sda? That leaves possible anti-Lub. The RBCs could be cleared of IgG and typed or an Lu(b-) RBC could be tested with serum and eluate. And, this could be an autoantibody...And then going back to a sample to blood bank for broken wrist, perhaps more going on diagnostically here, What was admission Hgb? Transfusion history is important for auto vs allo specificity. With the eluate stronger than the serum and with mf in DAT, should be concerned about possible transfused cells and this being an alloantibody.
  2. If there is suspicion the patient was unknowingly transfused (has the patient been asked?), you could compare the genotype panel of peripheral blood and the phenotype (and look for mixed field in other typings)
  3. I offer the following based on experience with the MMA and antibodies to antigens of high prevalence and should not be taken as clinical recommendations. The National Reference Laboratory for Blood Group Serology for the American Red Cross has performed Monocyte Monolayer Assays (MMAs) in over 200 cases of patients with anti-Yta in order to determine which patients have antibodies of potential clinical significance. The MMA has been performed for more than 30 years. The reason to perform the MMA is to conserve the supply of Yt(a-) units for patients who have had either had decreased survival of transfused RBCs or who have a positive MMA. But the MMA is only useful for determination of transfusion recommendations for the mother, the MMA for prediction of Hemolytic Disease of the Fetus and Newborn has not been found to be useful in studies performed in George Garratty's Research Laboratory in Los Angeles. For cases like these, an MMA is recommended if blood is thought to be needed for the mother at delivery. Then if a physician determines that the mother can donate autologous units that would be useful. In some cases, 3 different donations can be made with the first two being frozen, one into two aliquots for possible use by the infant and one as a whole unit for the mother's possible use. The final unit can be drawn in order that it will be in-date at the time of the planned delivery. Autologous units do not generally have to follow the same rules as allogeneic donation, and can allow for more frequent donation and at a lower hemoglobin in accordance with the physician order. Alternatively or in addition, a request can be placed by an American Rare Donor Program member for potential units for delivery if autologous units cannot be obtained. And, after delivery, when the woman is eligible for donation, she should be encouraged to donate, not only for herself, but for others. Her siblings should also be tested as they have a 1:4 chance of being Yt(a-). It is assumed that pregnancies like these are monitored by non-invasive means. Most often, antibodies such as anti-Yta, seldom clinically significant for HDFN, are monitored by titer, reviewing for increases in titer (although not mentioned), and then, by clinical protocol. Opinions vary on critical titer value in non-D antibodies, but most agree that increases in titer are reviewed for further studies or early delivery. Perhaps not especially needed in this case, but in cases of antibodies to high prevalence antigens, knowledge of the father's ABO and D status, especially prediction of zygosity of the father's D type might be useful in the very rare event of HDFN because O D negative Yt(a-) blood may be challenging. Sandra Nance, MS, MT(ASCP)SBB, Senior Director, American Rare Donor Program
  4. In the USA, all AABB accredited IRLs (Immunohematology Reference Laboraotories) and American Red Cross IRLs are members of the American Rare Donor Program (ARDP). This program has over 45,000 Rare Donors registered from over 88 member centers. If your blood supplier is not a member of the ARDP, your facility can access the program by sending a sample for evaluation to a member. If there are no member centers in your area, the Penn-Jersey American Red Cross can be a "portal" to the ARDP. After a sample is submitted and tested, Penn-Jersey will access the ARDP for the non-member hospital or blood center. Ninety four percent of the time, units are found. In very complex cases, there may be no blood available. If the blood is not avaiable in the USA, then the ARDP, as a member of the World Health Organization (WHO) International Rare Donor Panel(IRDP), can request blood internationally after several qualifying steps are taken (prove no blood in USA, eligible sibling donors have been tested, MMA performed, patient and physician give permission). The WHO IRDP is managed by the International Blood Group Reference Laboratory headquartered in Bristol, UK under the direction of Nicole Thornton. No patient should be without the blood they need to survive, although some are very very rare with very few identified donors in the world [e.g. Rhnull, En(a-), Ko, Co(a-b-)] and that makes it difficult to supply lifesaving blood. Sandra Nance, Senior Director, American Rare Donor Program, 1- 215 451 4362
  5. The Monocyte Monolayer Assay has been used successfully for over 30 years in the USA to predict the outcome of incompatible transfusion in the face of an antibody to a high prevalence antigen. These results have been extremely useful in the stewardsip of the Rare Blood Supply since a negative result means that the patient can be transfused random products for that tranfusion. If the patient is transfused, another MMA must be performed before another random transfusion can be given and be performed as close to the time of the next transfusion as possible. This assay is performed in the National Reference Laboratory for Blood Group Serology at the American Red Cross in Philadelphia and in the research laboratory that was under Dr George Garratty at the American Red Cross in Southern California as well as at least two other centers in the USA. The American Rare Donor Program recommends that an MMA be performed in cases where rare blood is not available. In fact, this was the topic of the 2014 Sally Frank Award Program at teh Annual AABB Meeting. This assay is perfomed in a number of centers in the USA. In recent years, other countries have requested training in MMA (Switzerland, Brazil, South Africa) because of the usefulness in transfusion recommendations. If any centers have an interest in MMA implementation, i would recommend one on one training in a center that is performing the assay. It is not complicated, but is technically demanding. Sandra Nance, MS, MT(ASCP)SBB Sr Director, IRLs American Red Cross
  6. Very cute, started the morning off with a smile! Merry Christmas
  7. While a useful method for antibody detection, it is controversial whether the Gel method is superior to tube methods in the investigation and identification of red cell antibodies. The American Red Cross has 40 IRL locations across the USA. With that number of IRLs, there are thousands of hospital and other blood center customers with different methodologies that refer samples to the ARC. The IRLs choose methods that are best suited to the majority of their local customers and methods that are able to detect clinically relevant antibodies as required by AABB Standards. Facilities with Gel as their primary method usually purchase the Gel screening cells along with the Gel panels premade by Ortho. This means that when the sample is referred to the ARC IRL, the commercially available panels have usually been tested and those panel results are submitted to the IRL. Retesting those exact panels is a waste of resources and the customers would have higher bills and a longer turnaround time for final results. To continue the testing in Gel, the IRL must prepare red cells from other manufacturers to use in Gel method. This is off package insert for those other manufacturers’ red cells. It still could be done, but there is an extra expense in time resources to prepare those cells. Some IRLs do prepare the cells and test by Gel, others use a method with similar sensitivity such as PEG, to investigate the reactivity as this is faster and gets the answer to the facility sooner. Other techniques such as adsorptions, enzyme treatment, neutralizations are often needed and the Gel manufacturers have not validated those sample sources for Gel testing. In house validations of the Gel techniques with those sample sources have not been uniformly successful. In conclusion, the ARC IRLs have many methodologies in their arsenal which are often needed, some IRLs have as many as 200 SOPs, and the ARC IRL Technologists are highly trained to utilize the best methods to obtain the answer. A useful reference is: Determination of optimal method for antibody identification in a reference laboratory Immunohematology 2011; 27:146-150.
  8. The American Red Cross in Philadelphia has performed QC for Fibrinogen and Factor VIII levels on American Red Cross and non-Red Cross Cryoprecipitated-AHF products for over 20 years. If you wish to investigate sending your Cryo for QC to the American Red Cross, please contact Cynthia Flickinger at 215 451 4909.
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