Alloantibodies in RBC units
Alloantibodies in RBC Units (PDF)
In January 2019, Dr. Matthew Yan, a medical officer with Canadian Blood Services, published an article about blood donors with red blood cell (RBC) alloantibodies.
“A very small percentage of RBC units, less than 0.5 per cent, are manufactured from blood donors with red cell antibodies,” says Dr. Yan. These donors may have antibodies directed against common non-ABO antigens (e.g. Rh or Kell system) detected during routine screening. The incidence in our donor population is much lower than found in hospital patients, which has been reported to be approximately 3 per cent (Evers et al., Lancet, June 2016).
Given the small percentage of RBC units with antibodies, some hospital transfusion services may not have experience handling and transfusing these units. In general, these RBC units are considered safe to transfuse for all adult populations, regardless of the patient’s RBC phenotype, but should be avoided in pediatric patients.
The full article includes a theoretical calculation to illustrate the likely insignificance when these RBC units are transfused to an adult.
Read the full article.
Related customer letter: 2010-17, Packed Red Blood Cell Units from donors with Red Blood Cell Antibodies.
To read more articles, please visit the BloodNotes section of blood.ca
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Global search for rare blood donors
Global Search for Rare Blood Donors (PDF)
There’s an old proverb that it takes a village to raise a child, and when a child is sick and needs saving, the international transfusion medicine community has shown time and again it will come together to do whatever it takes. That was the case recently for a three-year-old in the United States with a rare blood type.
Zainab is being treated for neuroblastoma, a type of cancer that is most common in babies and young children. She and her family live in Florida, where she is undergoing treatment.
Zainab lacks the Indian b antigen and has anti-Inb. She needs red blood cells from donors who also lack the Indian b antigen, and are group A or O. Although rare, people from Pakistan, India, or Iran are most likely to share this antigen type.
To date, five Indian b negative compatible donors have been found in the United States, United Kingdom, and Australia. Although this is encouraging, the search continues for a total of seven to ten compatible donors to support this young patient during her treatment. An Indian b negative Canadian donor identified by Canadian Blood Services was unfortunately not crossmatch compatible for Zainab, but our search continues with the help of many donors in Canada who have come forward.
For more information, go to OneBlood.
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In September 2018, Dr. Gwen Clarke, associate medical director with Canadian Blood Services, posted an updated article about anti-M which addresses testing strategies to manage patients with anti-M.
Anti-M is very rarely associated with hemolytic disease of the fetus and newborn, and does not typically contribute to acute or delayed hemolytic transfusion reactions. An exception is anti-M in some patients with sickle cell disease. In this context, anti-M can contribute to hemolysis or even trigger hyper-hemolysis.
When anti-M is detected in a patient’s pre-transfusion sample testing, it is generally considered to be a clinically insignificant antibody. There is usually no requirement for selection of M antigen negative donor red blood cells. Instead, red blood cell units that are crossmatch compatible to the IAT stage or equivalent using IgG antihuman globulin should be selected for transfusion.
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Pathogen inactivation – a primer
Pathogen Inactivation – A Primer (PDF)
Canadian Blood Services is committed to blood safety because lives depend on it. A number of safeguards are in place to reduce the risk of infectious disease transmission from donor to patient. Despite these safeguards, the risk of infectious disease transmission, though very low, remains.
Pathogen inactivation technologies could help to tackle those gaps and make the blood supply even safer. Rather than focusing on the detection of specific, known pathogens, these technologies focus on inactivating any pathogens that may be present in a blood product. These technologies add a new layer of safety against emerging or unknown pathogens. Pathogen inactivation is often called a paradigm-altering approach because it is a pro-active rather than a re-active approach to blood safety.
Canadian Blood Services has been studying and evaluating pathogen inactivation technologies for some years. Recently, through our Centre for Innovation we've been working to understand how these technologies would work in our manufacturing system, and how they would impact the quality of our blood products and ultimately patient safety.
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Transfusion-related acute lung injury (TRALI)
Transfusion-related acute lung injury (TRALI) (PDF)
TRALI is a rare but serious syndrome characterized by sudden acute respiratory distress following transfusion. It is defined as new, acute lung injury (ALI) during or within six hours after blood product administration in the absence of temporally-associated risk factors for ALI.
In February 2019, Dr. Tanya Petraszko, associate medical director with Canadian Blood Services, published an online article about TRALI.
“TRALI remains the highest cause of transfusion-related morbidity in Canada”, says Dr. Petraszko. The mortality rate of TRALI is reported as high as 20 per cent in general populations and up to 58 per cent in critically ill patient populations.
The article includes information for reporting this serious adverse transfusion reaction, and what Canadian Blood Services is doing to prevent these reactions from occurring.
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