Editing Blood type (section)

===Blood transfusion===
{{Main|Blood transfusion}}
Transfusion medicine is a specialized branch of [[hematology]] that is concerned with the study of blood groups, along with the work of a [[blood bank]] that provides a [[Blood transfusion|transfusion]] service with blood and other blood products. Across the world, blood products must be prescribed by a medical doctor (licensed [[physician]] or [[surgeon]]) in a similar way as medicines.{{citation needed|date=November 2021}}

[[File:Main symptoms of acute hemolytic reaction.png|thumb|right|220px|Main symptoms of [[acute hemolytic reaction]] due to blood type mismatch.<ref>[https://www.cancer.org/docroot/ETO/content/ETO_1_4x_Possible_Risks_of_Blood_Product_Transfusions.asp Possible Risks of Blood Product Transfusions] {{Webarchive|url=https://web.archive.org/web/20091105182210/http://www.cancer.org/docroot/ETO/content/ETO_1_4x_Possible_Risks_of_Blood_Product_Transfusions.asp |date=2009-11-05 }} from American Cancer Society. Last Medical Review: 03/08/2008. Last Revised: 01/13/2009</ref><ref>[https://www.pathology.med.umich.edu/bloodbank/manual/bbch_7/index.html 7 adverse reactions to transfusion] {{Webarchive|url=https://web.archive.org/web/20151107032014/https://www.pathology.med.umich.edu/bloodbank/manual/bbch_7/index.html |date=2015-11-07 }} Pathology Department at University of Michigan. Version July 2004, Revised 11/5/08</ref>]]

Much of the routine work of a [[blood bank]] involves testing blood from both donors and recipients to ensure that every individual recipient is given blood that is compatible and as safe as possible. If a unit of incompatible blood is [[Blood transfusion|transfused]] between a [[Blood donation|donor]] and recipient, a severe [[acute hemolytic reaction]] with [[hemolysis]] (RBC destruction), [[kidney failure]] and [[shock (circulatory)|shock]] is likely to occur, and death is a possibility.<ref>{{cite book |last1=Rout |first1=Preeti |last2=Harewood |first2=Janine |last3=Ramsey |first3=Adam |last4=Master |first4=Samip R. |title=StatPearls |date=2024 |publisher=StatPearls Publishing |chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK448158/ |chapter=Hemolytic Transfusion Reaction |pmid=28846280 }}</ref> Antibodies can be highly active and can attack RBCs and bind components of the [[complement system]] to cause massive hemolysis of the transfused blood.<ref>{{cite journal |vauthors= Fujii Y |title=Prevention of ABO-incompatible transfusion |journal=Masui |volume=60 |issue=1 |pages=47–54 |year=2011 |pmid=21348250 }}</ref>

Patients should ideally receive their own blood or type-specific blood products to minimize the chance of a [[transfusion reaction]]. It is also possible to use the patient's own blood for transfusion. This is called [[autotransfusion|autologous blood transfusion]], which is always compatible with the patient. The procedure of washing a patient's own red blood cells goes as follows: The patient's lost blood is collected and washed with a saline solution. The washing procedure yields concentrated washed red blood cells. The last step is reinfusing the packed red blood cells into the patient. There are multiple ways to wash red blood cells. The two main ways are centrifugation and filtration methods. This procedure can be performed with microfiltration devices. Risks can be further reduced by [[cross-matching]] blood, but this may be skipped when blood is required for an emergency. The oldest form of cross-matching involves mixing a sample of the recipient's serum with a sample of the donor's red blood cells and checking if the mixture ''agglutinates'' or forms clumps. If agglutination is not obvious by direct vision, blood bank technologist may check for [[Agglutination (biology)|agglutination]] with a [[microscope]]. If agglutination occurs, that donor's blood cannot be transfused to that particular recipient.  In a bank transfusion service, it is vital that all blood specimens are correctly identified, so labelling has been standardized using a [[barcode]] system known as [[ISBT 128]].

The blood group may be included on [[Dog tag (identifier)|identification tags]] or historically on [[tattoo]]s worn by military personnel, in case they should need an emergency blood transfusion. Frontline German [[SS blood group tattoo|Waffen-SS had blood group tattoos]] during [[World War II]].

Rare blood types can cause supply problems for [[blood bank]]s and hospitals. For example, [[Duffy antigen|Duffy]]-negative blood occurs much more frequently in people of African origin,<ref>{{cite journal |author=Nickel RG |title=Determination of Duffy genotypes in three populations of African descent using PCR and sequence-specific oligonucleotides |journal=Human Immunology |volume=60 |issue=8 |pages=738–42 |date=August 1999 |pmid=10439320 |doi=10.1016/S0198-8859(99)00039-7 |author2=Willadsen SA |author3=Freidhoff LR |display-authors=3 |last4=Huang |first4=Shau-Ku |last5=Caraballo |first5=Luis |last6=Naidu |first6=Raana P |last7=Levett |first7=Paul |last8=Blumenthal |first8=Malcolm |last9=Banks-Schlegel |first9=Susan|doi-access=free }}</ref> and the rarity of this blood type in the rest of the population can result in a shortage of Duffy-negative blood for these patients.  Similarly, for RhD negative people there is a risk associated with travelling to parts of the world where supplies of RhD-negative blood are rare, particularly [[East Asia]], where blood services may endeavour to encourage Westerners to donate blood.<ref>{{cite web|url=https://www.bloodcare.org.uk/html/resources_chairman_2001.htm |title=BCF&nbsp;– Members&nbsp;– Chairman's Annual Report |access-date=2008-07-15 |last=Bruce |first=MG |date=May 2002 |publisher=The Blood Care Foundation |quote=As Rhesus Negative blood is rare amongst local nationals, this Agreement will be of particular value to Rhesus Negative expatriates and travellers |url-status=dead |archive-url=https://web.archive.org/web/20080410111425/https://www.bloodcare.org.uk/html/resources_chairman_2001.htm |archive-date=April 10, 2008 }}</ref>