Prab at 13:25, 17 September 2023

2023-09-17T13:25:02Z

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The '''ABO blood grouping system''' is a fundamental classification of human blood types, determined by the presence or absence of specific antigens on red blood cells and antibodies in the plasma. These antigens and antibodies dictate a person's blood type and compatibility for blood transfusion. The ABO system is universally recognized as the most significant system for blood transfusion compatibility.
[[File:ABO blood type.svg|thumb|right|410px|ABO blood group [[antigen]]s present on [[red blood cell]]s and [[IgM]] [[antibodies]] present in the [[Blood serum|serum]]]]
===Understanding Blood Groups===

The ABO blood grouping divides blood into four main types, determined by the presence or absence of two main antigens and antibodies. The categorization is as follows:

{| class="wikitable"
! ABO Group !! Blood Type !! Antigen A !! Antigen B !! Anti A antibody !! Anti B antibody
|-
| A || yes || no || no || yes
|-
| B || no || yes || yes || no
|-
| O || no || no || yes || yes
|-
| AB || yes || yes || no || no
|}

For instance, an individual with the A blood type has A antigens and anti-B antibodies. This system ensures safe blood transfusions, as the recipient's immune system could attack incompatible blood.

==Blood Donation Screening==

Ensuring the safety of both blood donors and recipients is paramount. Screening procedures are in place to minimize the risk of transfusing infectious diseases.

===Donor Evaluation===

Before donation, potential donors undergo a questionnaire to assess their eligibility. Those at risk of carrying transmittable diseases or who are unwell are deferred.

===Testing Donated Blood===

After donation, the blood undergoes multiple tests:

* Blood typing (ABO group)
* Rh typing (positive or negative)
* Screening for infectious pathogens

{| class="wikitable"
! Infectious Disease Pathogen !! Laboratory Tests Used
|-
| Bacterial Contamination || Bacterial culture
|-
| Hepatitis B virus (HBV) || Hepatitis B surface antigen (HBsAg) detection<br>Hepatitis B core antibody (anti-HBc) detection
|-
| Hepatitis C virus (HCV) || Hepatitis C virus antibody (anti-HCV) detection<br>Nucleic acid amplification testing (NAT) for HCV
|-
| Human Immunodeficiency virus Types 1 and 2 (HIV) || HIV-1 and HIV-2 antibody (anti-HIV-1 and anti-HIV-2) detection<br>Nucleic acid amplification testing (NAT) for HIV-1
|-
| Human T-Lymphotropic Virus Types I and II (HTLV) || HTLV-I and HTLV-II antibody (anti-HTLV-I and anti-HTLV-II) detection
|-
| Treponema pallidum (syphilis) || Anti-treponemal antibody detection
|-
| West Nile virus (WNV) || Nucleic acid amplification testing (NAT) for WNV
|}

==Adverse Reactions to Blood Transfusions==

While the risk of an adverse reaction during a blood transfusion is low, it's vital to understand potential complications. Reactions can range from mild allergic responses to severe and life-threatening conditions.

===Common Reactions===

* '''Allergic reaction to blood transfusion''': Caused by a clash between the transfused allergen and the recipient's pre-existing antibodies.
* '''Acute hemolytic transfusion reaction (AHTR)''': Rapid destruction of red blood cells due to receiving an incompatible blood type.
* '''Delayed hemolytic transfusion reaction (DHTR)''': The body develops antibodies against transfused red blood cell antigens after 24 hours to 28 days post-transfusion.
* '''Delayed serologic transfusion reaction (DSTR)''': New antibodies against red blood cells develop within 24 hours to 28 days post-transfusion without clinical symptoms.
* '''Febrile non-hemolytic transfusion reaction (FNHTR)''': Characterized by fever and/or chills without the breakdown of red blood cells.
* '''Hypotensive transfusion reaction''': A drop in blood pressure immediately after starting the transfusion.

===Rare Reactions===

* '''[[Post-transfusion purpura]] (PTP)''': Rapid destruction of platelets, leading to a sharp decrease in platelet count.
* '''[[Transfusion-associated circulatory overload]] (TACO)''': Fluid overload in the recipient's circulatory system.
* '''[[Transfusion-related acute lung injury]] (TRALI)''': Fluid accumulation in the lungs.
* '''[[Transfusion-associated dyspnea]] (TAD)''': Respiratory distress post-transfusion.
* '''[[Transfusion-associated graft vs. host disease]] (TAGVHD)''': Donor T-lymphocytes attack the recipient's cells, causing symptoms such as fever and rash.
* '''[[Transfusion-transmitted infection]] (TTI)''': Introduction of a pathogen through transfused blood.
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{{Transfusion medicine}}
[[Category:Blood antigen systems]]
[[Category:Transfusion medicine]]
[[Category:Antigenic determinant]]
[[Category:Hematopathology]]
[[Category:Glycoproteins]]
[[Category:Serology]]
[[Category:Genes on human chromosome 9]]
[[Category:Health and Medicine]]
[[Category:health]]
[[Category:hematology]]

Abo blood groups - Revision history

Prab at 13:25, 17 September 2023