Chapter 14 Red Blood Cell and Bleeding Disorders pages 629-654 Flashcards
What would occur to the blood of someone involved in a traumatic accident?
Anemia by blood loss-
Interstitial fluid restore blood volume
–> erythropoiesis of kidney is stimulated and creation of CFU-E is stimulated
MASSIVE blood loss- bp drops, granulocytes will be mobilized= leukocytosis
RBCs seem normal but there are a lot of reticulocytes
Early recovery from blood loss is accompanied by thrombosis (increase platelet production)
Define extravascular hemolysis.
When RBCs are destroyed inside the phagocyte
this is the majhority of RBC destruction in hemolytic anemias
Usually happens when RBC is unable to morph
Define intracellular hemolysis.
Caused by mechanical injury, parasites, etc.
Symptoms may include jaundice.
Why does extravascular hemolysis cause splenomegaly?
RBCs are unable to morph causing slow blood flow and the inability of the RBCs to morph can lead to a blockage in the spleen
Bilirubin is unconguated in all types of ____ ______.
Hemolytic anemias
What is hereditary spherocytosis?
RBCs are spherical and unable to deform cause my mutations in the cell skeletal components
Whata are the characteristic clinical features of hereditary spherocytosis?
Anemia, jaundice and splenomegaly
What is glucose-6 phosphate dehydrogenase deficiency?
Abonormalities in the hexose monophosphate shunt OR glutathione metabolism resulting from deficient or impared enzyme function reduce the ability of red cells to protect themselves against oxidative injuries and lead hemolysis
Why is G6PD anemia episodic?
The episodic hemolysis is caused by exposures that generate oxidant stress
for example, infection, certain drugs (antimalarials), foods (fava beans)
What would a blood smear of a patient with G6PD deficiency look like?
It would have Heinz bodies– exposure of G6PD-deficient red cells to high levels of oxidants causes cross-linking of reactive sulfhydryl groups on globin chains– become denatured and form these membrane-bound precipitates
bite cells are produced from splenic macrophages
What is Sickle Cell caused by?
A point mutation in Beta-globin
What effect does the point mutation on Beta-globin in Sickle cell cause?
promtoes polymerization of deoxygenated hemoglobin, causes RBC distortion, hemolytic anemia, microvascular obstruction, ischemic tissue damage (less blood flow)
Intracellular dehydration and decreas in pH in sickle cell leads to what?
Intracellular dehydration–>high MCHC (mean cell hemoglobin concentration)–> more sickling
Decrease pH–> decrease oxygen affinity–> more sickling
What is severe hemolytic anemia associated with?
reticulocytosis, hyperbilirubinemia, and the presence of irreversibly sickled cells
What is a vaso-occlusive crises?
Also paincrises; episodes of hypoxic injury and infarction that cause severe pain in the affected region
What is it called when RBCs are trapped in the spleen, leading to an enlarged spleen?
Sequestration crises
A mutation that decreases the synthesis of alpha/beta chains of adult hemoglobin.
Thalassemia- leads to anemia, hypoxia, hemolysis
decreased RBC lifespan and decreased production
A patients blood smear reveals microcytic RBCs; what anemia could this be and what role does the size of the RBC play in function?
Beta Thalassemia
RBCs are ‘underhemoglobized’ therefore, less oxygen carrying capacity
What is the difference between beta-thalassemia major and minor?
Major- 2 beta- thalassemia alleles
severe, transfusion-dependent anemia
Minor- one beta-thalassemia gene and one normal
mild asymptomatic microcytic anemia
What is hydrop fetalis?
In fetuses, deletion of alpha globin, gamma globin forms a tetramer that takes up the oxygen leaving the tissues with no oxygen
What is PIGA (phosphatidylinositol glycan complementation group A gene) and what is PNH (paroxysmal nocturnal hemoglobinuria)?
PIGA is an enzyme essential for the syntehsis of certain membrane associated complement regulatory proteins
PNH occurs because of mutations in the PIGA, it is deficient in GPI linkers on the membrane. Red cells deficient in these GPI linked factors are abnormally susceptible to lysis or injury
Which linker types are negatively effected in PNH?
CD55, CD59, C8
What is the only type of anemia caused by a genetic DEFECT?
Paroxysmal nocturnal hemoglobinuria (PNH)
What type of anemia would be present in someone with B12 or folate deficiency?
Megaloblastic anemia
Hematopoiesis is ineffective
What is the most common anemia world wide and what is the cause?
Iron deficiency anemia
lack of iron in diet, poor absorption, chronic blood loss
When does hypochromic microcytic anemia result?
A result of iron deficiency anemia
small, pale RBCs
Define immunohemolytic anemia.
Antibodies bind and destroy RBCs
What test might be run to rule out immunohemolytic anemia in a patient?
direct Coombs antiglobulin test
What is reduced in alpha thalassemia?
Reduced synthesis of alpha globin chains
What results from from screwed erythropoiesis?
Improper bone development and iron accumulation
