MODULE 3 - MONOSACCHARIDES IN BLOOD GROUPS

• Blood is slightly more dense and approximately 3-4 times more viscous than water
• Blood consists of cells suspended in a liquid
• Three layers are visible in centrifuged blood:

  • Plasma forms at the top (~55%)
  • Buffy coat forms below the plasma and contains white blood cells and platelets
  • Red blood cells form the heavy bottom portion of the separated mixture (~45%)
• The four main components of blood are:

  • Red Blood Cells: carry oxygen, nutrients, and wastes
  • White Blood Cells: fight diseases and protect the body from infection
  • Plasma: straw-colored liquid where the other components float in
  • Platelets: gather at the site of injury and help the clotting process
• Blood volume is variable but tends to be about 8% of body weight, with the average adult having about 5 liters of blood
• Blood type, also called a blood group, is based on the presence or absence of inherited antigenic substances on the surface of RBCs
• The ABO blood group system is the most important blood group system in human blood transfusion
• Karl Landsteiner discovered the ABO blood group system in 1900 and began investigating why some blood transfusions work and some do not
• Blood typing principle: DIRECT/FORWARD METHOD

  • When red cells are mixed with commercial anti-sera (anti-A and anti-B soluble antibodies), agglutination will occur on the slides containing cells positive for the corresponding antigen
  • No agglutination will occur when the red cells do not contain the corresponding antigen
• BLOOD TYPING - REVERSE METHOD

  • uses the patient's plasma or serum, combined with reagent group A and group B red blood cells, to determine which ABO antibodies are present
• The Rh blood type system was discovered in 1940 by Karl Landsteiner and Alexander Wiener
• Rh factor incompatibility:

  • When a mother-to-be and father-to-be are not both positive or negative for Rh factor, it's called Rh incompatibility
  • In its mildest form, Rh incompatibility causes the destruction of red blood cells, leading to jaundice in the infant
  • Erythroblastosis fetalis can be prevented by administering a serum (Rho-GAM) to the mother around the 28th week of pregnancy and within 72 hours after the delivery of an Rh+ baby
• Anti-A antibodies and Anti-B antibodies are usually “Immunoglobulin M" , abbreviated IgM, antibodies
• N-Acetylgalactosamine is the primary marker present in Type A Blood Group
• D-Galactose is the primary marker present in Type B Blood Groups
• There is no primary marker in Type O Blood Group
• The antigen markers present in Blood groups are A-Acetylgalactosamine, D-Galactose, N-Acetylglucosamine, L-Fucose
• Type O is know as the universal blood donor which means it can donate to Blood Groups O, A, B, and AB. It has antibodies against A and B and can only receive blood group from O.
• Type A has antibodies against Type B and can only receive from blood groups A and O. It can donate blood to blood groups A and AB (only emergency)
• Type B has antibodies against Type A and can only receive from blood groups B and O. It can donate blood to blood groups B and AB (only emergency)
• Type AB has no antibodies against other blood groups which means it is the universal blood receiver. It can receive from blood groups O, A, B, and AB and can only donate blood to blood groups AB.