Lecture 5.1 Highlights Flashcards by Morgan Evans

What is one lab you should always measure the change of?

Hemoglobin

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What leads to the release of unconjugated bilirubin? Why?

1) RBC lysing
2) The bili wasn’t able to be conjugated through normal delivery to the liver

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Hemolysis leads to an increase in what? What should you check?

Check the reticulocyte count; it will be high in chronic blood loss

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Intravascular and extravascular hemolysis both can cause increased ________________ and decreased __________

unconjugated bilirubin; haptoglobin

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Hereditary Spherocytosis:
1) What part of the RBC is defective?
2) What does this do to the cell?

1) Membrane
2) Spherical, non-deformable

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Hereditary Spherocytosis:
1) Is caused by mutations in either one of two proteins; what are they?
2) What do these mutations do?
3) What happens to affected RBCs?

1) Ankyrin or spectrin
2) Cytoplasm released until surface to volume ratio is decreased forming a sphere
3) Destroyed by macrophages in the spleen

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How is hereditary spherocytosis (which causes extravascular hemolysis) treated?

Splenectomy

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Sickle cell is caused by a single amino acid substitution leading to valine in place of glutamate at 6th amino acid position on the _____________

beta hemoglobin

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Sickle cell causes Hg____ to be turned into Hg____

HgA; HgS

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Sickle cell: Under _________ conditions, cells with this mutation undergo _____________ change, which is irreversible

hypoxic; sickled structural change

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Sickle cell: Each sickle-forming episode leads to influx of calcium which leads to K and H20 loss and damages ____________

membrane skeleton

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Sickled cells _____________ easily and become stuck in ______________

hemolyze; microvasculature

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HgA and HgF: By _____________ of age gamma-globin is gradually replaced with beta-globin

six months

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HgF is a combination of ______________ and alpha-globin

gamma-globin

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When is the onset of sickle cell Sx?

6 months old

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Sickle Cell vasoocclusive crises in body are characterized by what?

Pain

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Thalassemias are disorders associated with what?

Imbalance in production of alpha or beta globin

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Thalassemias causes the formation of hemoglobin molecules that have what?

An abnormal number of alpha or beta globins

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Why are Thalassemias a problem?

The alternate hemoglobins do not bind oxygen efficiently and can be lethal

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What is the most common cause of alpha thalassemia?

Deletion(s) of one or both alpha globin genes

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There are _____ different genes for alpha globin, and thus _____ alleles

two; 4

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1) What is the most common cause of beta thalassemia?
2) How many genes and alleles are involved?

1) Single-base pair substitutions that result in proteins that have either reduced activity, altered activity, or no activity at all
2) One gene with two alleles

Beta Thalassemia:
Decreased ______________ production leads to in imbalance in globin synthesis and the precipitation of _______________.

beta-globin; excess chains

Alpha chains don’t form their own tetramers; what do they do instead?

Accumulate in the cell and form a Heinz Body

Beta thalassemia: patients suffer from _______________ due to dietary intake which cannot be accommodated by functional RBCs

iron overload

1) Carriers of one beta-thalassemia allele are clinically well, and have what condition? 2) Who would have a different version of this condition?

1) Thalassemia minor 2) In regions of the world where beta-thalassemia is common (malaria belt) individuals may be homozygous recessive or **compound heterozygotes** for two different beta-thalassemia alleles and have **thalassemia major**

What is a condition characterized by severe anemia and the need for lifelong medical management?

Beta thalassemia

Beta thalassemia major: Prominent cheekbones and protrusion of upper jaw result from ______________________ in bones of skull and face

expansion of marrow cavity

G6PD produces no symptoms until patients are exposed to environmental factors that increase what? Give examples

Oxidant stress (e.g., infectious agents, certain drugs and food, severe stress)

1) What type of anemia is G6PD? 2) Who does it affect?

1) Hemolytic anemia 2) 1 in 10 Black males

Peripheral blood smear shows RBC with precipitates of denatured globin, aka what?

Heinz bodies/ bite cells

List 4 diagnostic criteria for iron deficiency anemia

1) Transferrin saturation low 2) Total iron-binding capacity HIGH 3) Ferritin low 4) Microcytic red cells

Anemia of Chronic Disease: 1) Inflammatory _________ increases hepatic _________ 2) What does this block? 3) What else is occurring? 4) Will ferritin be high or low?

1) cytokines; hepcidin 2) Hepcidin blocks iron from being added to RBCs 3) Chronic inflammation blunts EPO synthesis 4) High

There's a high risk for folate deficiency in what two groups?

Poor nutrition and pregnant women

B12 anemia is accompanied by __________ symptoms

neurologic

B12 deficiency (megaloblastic): The anemia may be improved with the administration of folate, but what won't?

Neurological symptoms will not, and may even worsen

Aplastic Anemia: 1) What causes it? 2) What are half the cases? 3) What makes up the other half? 4) What are 3 Sx that can be seen in labs?

1) Suppression of multipotent myeloid stem cells 2) Idiopathic 3) Exposure [to myelotoxic agents] 4) Anemia, thrombocytopenia, neutropenia

Alpha thalassemia: 1) Once _______________ alpha-globin chains are lost, the cell experiences a vitally low amount of alpha-globin, so the remaining beta-globin pairs into a tetramer 2) This leads to formation of what in adults and what in infants?

1) Three or more 2) Its own tetramer beta-4 in adults, and gamma-4 in infants

Alpha thalassemia: What do tetramer beta-4 and gamma-4 have in common?

Both have high affinity for oxygen, so they won’t let it go

Give 2 examples of Alpha Thalassemia

1) Hb H (Beta 4) disease 2) Hydrops fetalis, Hb Bart’s (y4)

True or false: Alpha chains don’t form their own tetramers

True; they accumulate in the cell and form a Heinz Body

Beta Thalassemia pts suffer from ____________ overload due to dietary intake which cannot be accommodated by functional RBCs

iron

Anemia of Chronic Disease 1) Iron is actually being _________ so ferritin is high 2) Therefore, iron is not _________ so TIBC is low 3) The MCV remains _________ and the cells are not hypochromic

1) stored 2) desired 3) normal

1) What is bone marrow failure and pancytopenia caused by in aplastic anemia? 2) What are the two main causes?

1) Suppression of multipotent myeloid stem cells 2) Idiopathic + exposure

List 3 Sx of aplastic anemia

Anemia, thrombocytopenia, neutropenia

Define polycythemia

Polycythemia (erythrocytosis): the result of an abnormal increase in red blood cell number

Clonal proliferation of myeloid stem cells causes what?

Primary polycythemia (polycythemia vera)

1) What hormone is involved with secondary polycythemia's erythroid bone marrow hyperplasia? 2) What is usually the cause? 3) Give examples of causes

1) Erythropoietin 2) Prolonged hypoxia 3) Living at high altitudes, anoxia secondary to chronic lung disease, congenital heart disease, renal carcinoma

List 4 Sx of polycythemia vera

1) Hypertension 2) Dark red or flushed face 3) Headaches 4) Pruritis

What is a risk of polycythemia vera?

Increased risk of deep vein thrombosis (DVT),

Name something that causes lymphadenitis with the etiology of Bartonella hensale

Cat-Scratch Disease (most common in axilla and neck)

What happens in leukemia?

Bone marrow is infiltrated with malignant cells

Bleeding disorders: 1) TTP is caused by what? 2) What causes Hemolytic uremic syndrome?

1) Acquired or inherited deficiencies of ADAMTS 13 2) Deficiencies of complement regulatory proteins