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44 Cards in this Set

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What is HbA1c?
addition of glucose to the beta chain

Increased levels produced in diabetics with increased blood glucose levels
Tool for monitoring glucose control
Why do hemoglobinopathies normally not manifest until 6 months of age?
because Hb F is normally active until then
The most common disorders are mutations of the globin beta chain and include:
HbS
HbC
HbE
what are 3 major mechanisms of hemoglobinopathies
Altered function
Altered Stability
Altered solubility (seen in Hb S/C)
how can you identify abnormal Hb?
Hb electrophoresis

each Hb has different weight, so they migrate at different speeds
what is the substitution in sickle cell anemia?
Nonpolar valine is substituted for polar glutamic acid at the 6th position, in the the beta chain

aka there is a valine instead of a glutamate
what precipitates the formation of the crescent shaped RBC in Hb S?
Hypoxia, acidosis, hypertonicity and temperatures>37o promote deoxygenation and the formation of HBS polymers

The spleen, kidney retina and BM provide the above microenvironment
sickle cells will return to normal shape upon reoxygenation, how do you get irreversible sickled cells? (and thus anemia)
With repeated sickling the red cell membrane becomes leaky and rigid leading to irreversible sickled cells
Removed by spleen, liver or BM
what is the lifespan for an RBC in sickle cell anemia?
14 days

(norm is like 120)
how can sickle pts get autosplectomy?
their cells clog up the microvasculature leading to fibrosis of the spleen
what Accounts for the majority of clinical signs in sickle cell anemia?
Blockage of microvasculature by rigid sickled cells
Pain, low grade fever, tissue necrosis, and thrombotic problems (stroke, blindness, etc) can all be seen in what?
sickle cell anemia
what is aplastic crisis? what does it normally follow?
temporary cessation of erythropoiesis in the setting of chronic hemolysis leading to worsening of anemia

Follows viral, bacterial infections
what type of anemia is sickle cell?
Normochromic normocytic
Basophilic stippling can make you suspect what in general
hemoglobinopathy
what is Hydroxyurea? What is it used in?
Reduces sickling by reactivating fetal genes and elevating levels of HbF
Fewer vaso-occlusive events
Side effects: cytopenias
why do pts with sickle trait not have the signs of anemia?
Heterozyous condition

The one normal gene confers enough normal Hb to prevent symptoms or anemia
what is the mutation in Hemoglobin C?
Beta(6): Glu to Lys
in hemoglobin C, what do you see?
Target cells and

Intracellular Hb crystals
Both sickling and HbC crystal formation leading to vaso-occulsive crisis.
occurs in what hemoglobinopathy?
Hemoglobin S/C
what is a thalassemia?
Decreased globin chain synthesis:

Structural gene delections or
Mutations in controlling sites preventing gene expression.
what are the 2 variants of thalassemia?
Alpha thalassemia:
Impaired alpha chain synthesis

Beta thalassemia:
Impaired beta chain synthesis
Beta Variant
in thalassemia please list the relative levels in a CBC for

RBC count:
MCH
MCHC
MCV
RDW
Peripheral smear
RBC count: elevated
MCH: decreased
MCHC: decreased
MCV: DECREASED
RDW: normal or small
Peripheral smear: target cells
why is there an elevated RBC count in thalassemia?
Diminished synthesis of a globin chain
Too few cells with normal hemoglobin
Marked tissue hypoxia
Compensatory erythropoietin driving marked marrow hyperplasia and even greater ineffective erythropoiesis releasing increased numbers of red cells into the circulation
severe anemia with cardiac failure in the 1st decade, pt will have Chronic hemolysis with gallstones, gout and icterus
Splenomegally
Extramedullary hematopoiesis
BM hyperplasia with facial deformities

what does this describe
Beta Thalassemia: Homozygous Thalassemia Major
Homozygous Thalassemia Major is a lack of what?
Lack of Beta chain production
(for globin)
One normal beta gene is present directing nearly normal beta chain synthesis
RBC survival near normal except in stress or pregnancy when moderate Hypo/micro anemia develops.
Usually only a mild Hypo/micro anemia

this describes?
Beta Thalassemia:Heterozygous Beta Thalassemia Minor
which thalaseemia is a genetic mutation of one or more genes?
Alpha Thalassemia
Silent Carrier
Alpha Thal Trait
Hemoglobin H Disease
Hydrops fetalis with Hb Bart’s

are forms of what?
Alpha Thalassemia
no alpha genes =
Hydrops fetalis
what shifts the O2 curve to the right? what does this mean
this is stuff that drops O2 off the RBC

decrease pH
increase 23BPG
increase temp
increase CO2
A heterogeneous group of acquired or hereditary disorders characterized by Bone Marrow HYPOCELLULARITY =
Hypoproliferative Anemia
what are the 2 types of hypoproliferative anemia?
Pleuripotent: Aplastic Anemia with decrease in all 3 cell lines with peripheral pancytopenia
Unipotent: only one cell line affected, eg pure red cell aplasia
define aplastic anemia
BM cellularity <25% plus two of the following:

WBC count <0.5 x 109/L
Platelet count < 20,000
Anemia with corrected reticulocyte count <1%
what is pancytopenia?
reduction in the number of red and white blood cells, as well as platelets.
pancytopenia is typical, Relative reticulocyte count maybe normal but corrected retic count is always low.
Erythropoietin often increased

what do you see this in
Aplastic Anemia
BM infiltration by tumor, fibrosis or granulomas =
Myelophthisic Anemia

aka tumor cells fill the marrow and you can't undergo hematopoesis
what is leukoerythroblastic picture? what is it seen in?

***
Release of immature cells in peripheral blood: NRBCs, tear drop cells & neutrophilic left shift

Seen with Myelophthisic Anemia (leukemia, carcinoma, etc)
abnormal replacement disrupts the normal marrow architecture allowing release of immature cells. Anemia, thrombocytopenia or pancytopenia may be seen

this describes
Myelophthisic Anemia
tear drop cell is a tip off for what
a space occupying bone marrow lesion

like Myelophthisic Anemia
Anemia with NRBCs, polychromasia, teardrop cells, aniso/poikilocytosis
Neutrophil shift to the left, but total count variable
Platelets often large (indicating immaturity)

often seen in?
Myelophthisic Anemia
you have a pt with anemia and no matter what you do you cannot treat it. What do they have?
Myelodysplastic Syndrome
Clonal pluripotential stem cell disorder
Previously call pre-leukemia
BM maturation abnormalities characterized by BM hypercellularity with peripheral cytopenias, with anemia
Frequent chromosomal abnormalities

this describes what?
Myelodysplastic Syndrome
Anemia most consistent finding, often macrocytic by indices, but dimorphic on smear review.
Bicytopenia: 30%
Pancytopenia: 20%

this is seen in what?
Myelodysplastic Syndrome