Presentation on theme: "BLOOD GROUPS & TYPING. Blood Groups RBCs contain antigens (glycoproteins) for cell recognition (identification tags) The immune system has cells and chemicals."— Presentation transcript:
Blood Groups RBCs contain antigens (glycoproteins) for cell recognition (identification tags) The immune system has cells and chemicals that can recognize proteins as non-self proteins, try to destroy or inhibit protein’s that are foreign to the person’s body. – 30 common varieties - over 100 "family antigens" – common antigens - ABO and Rh cause vigorous transfusion reactions – others mainly used for ID purposes (paternity, inheritance, etc. - only typed in cases of several transfusions (cumulative effect)
Blood Typing Blood cell marker proteins can cause a life threatening immune reaction, determining the presence of these proteins help lessen the possibility of tissue rejection or transfusion reaction.
Antigen A molecule that triggers an immune response.
Antibody A type of plasma protein produced by the immune system. Antibodies react with non-self markers (antigens)and try to destroy or inhibit them.
ABO blood groups – based on presence or absence of A or B antigens on RBCs – plasma antibodies act against antigens not present on that individual's RBCs – see chart
One type of antigen-antibody reaction is when the antigens are “glued” together with antibodies. This clumping (agglutination) is the reaction that happens during an incompatible blood type transfusion.
In the ABO system, blood is mixed anti-A serum and anti-B serum, serum is plasma with clotting factors removed. Anti-A causes agglutination when the A antigen is present. Anti-B contains antibodies that react with the B antigen.
Rh factor (D antigen) Rh+ 85% of Americans - carry Rh antigen on RBC Rh- don't have antigen on RBC less severe transfusion reaction (hemolysis of donor RBCs) - doesn't usually occur until 2nd transfusion due to body's reaction time can cause erythroblastosis fetalis (hemolytic disease of the newborn) if Rh- woman carries Rh+ baby – 1 st baby is usually okay due to reaction time unless there was a bleeding problem during the pregnancy or a previous miscarriage or abortion. – 2 nd baby will have its blood cells attacked by mother’s antibodies- – Rhogam shot can prevent this if injected at 28 weeks of pregnancy and again right after birth.
Transfusions In case of blood loss, body tries to: – 1. reduce BV volume to maintain circulation to vital organs – 2. step up production of RBCs for replacement 15-30% loss - pallor & weakness over 30% - severe shock may be fatal substantial blood loss - whole blood transfusion Plasma, electrolyte solutions ( Ringer's solution) etc. can be used to increase blood volume while body steps up production of RBCs
Developmental Aspects Embryonic – Day 28 of pregnancy – RBC in fetal circulation – By 7 th month: red marrow is chief site of hematopoiesis – HbF – fetal hemoglobin Greater ability to pick up oxygen Replaced by HbA after birth Immature liver may lead to physiological jaundice
Developmental Aspects Adulthood – Dietary deficiencies or metabolic disorders cause abnormalities in BC formation or hemoglobin production – Iron deficient anemia more common in women
Developmental Aspects Old age – Leukemia risk – Pernicious anemia Stomach mucosa atrophies with age Less intrinsic factor (located in lining of stomach – function is B12 absorption) Less B12 absorption Leads to pernicious anemia
Diagnostic Blood Tests low hematocrit = anemia high fat level (lipidemia) = problems with heart disease blood glucose test – diabetes, hypoglycemia, hyperglycemia differential WBC indicates type of infection platelet count – thrombocytopenia – clotting problems complete blood count = CBC – see handout