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Flashcards in hemolytic anemia wk7 mon9am Deck (18):
1

Lab Eval of hemolysis

- reticulocytosis with any MCV

- polychromatophila of erythrocytes

- erythroid hyperplasia of bone marrow

- increased indirect bilirubin

increased urinary and fecal urobilinogen

- increased endogenous CO production

- depleated unbound haptoglobin

2

Erythrocyte features in hemolytic anemias

- fragmentation

- spherocytosis

- distinct erythrocyte morphology

- erythrocyte inclusion

 

3

DDX of splenomegaly

- portal hypertension

- infiltrative disorders of spleen

- cardiomyopathy

- autoimmune disease

- subcapsular hemmorrhage

- hematologic disorders (hemolysis, hemoglobinopathy, neoplastic)

4

vascular disorders

1. macroangiopathic hemolytic anemias- heart valves sheer RBC

2. microangiopathic hemolytic anemias

- disseminated intravascular coagulation

- malignant hypertension

- thrombotic thrombocytopenic purpura

-hemolytic uremic syndrome

-other physical causes of hemolysis such as March hemoglobinuria and thermal injury

 

5

Membraneopathies

- membrane defects

1. congenital 

- hereditary sphereocytosis, elliptocytosis, stomatocytosis and acanthocytosis

2. acquired

- immunohemolytic anemias, immune hemolysis, Rh incompatibility, autoimmune hemolytic anemia, drug-induced heolytic anemia

 

6

Hemoglobinopathies

The change in the amino acid may give new charecteristics to the hemoglobin and lead to:

- increased HG precipitation (sickle cell)

- instability of HG

- Inability to keep iron in reduced form within the HG molecule (methemoglogins)

- altered O2 affinity of the HG molecule (high affinity or low affinity molecules)

7

Hemoglobin genes

Chromosome 16-  2 alpha 

Chromosome 11- 1 beta

8

Hemoglobin types

Hg A- a2b2 Major adult (>95%)

Hg A2= a2d2 minor adult (<3%)

Hg F = a2g2 major Hg in fetus (<2%in adults)

9

SS anemia (sickle cell) clinical findings

Lab

- low grade anemia

- erythroid hyperplasia

- extravascular hemolysis

- hyperbilirubinemia (indirect)

Symtoms

- pain, bone infarcts, lungs, CNS, heart, renal, autosplenectomy, infections

10

SS clinical course

Variable

85% to age 20

60% to age 50

cause of death

- age 0-10: infection, splenic sequestration, acute chest syndrome, stroke, cardiovascular

- age >10: acute and chronic chest syndrome, infection, CVA, renal , cardiac, other

11

Thalassemias

Hereditary anemias with diverse clinical expressions, due to a quantitative decrease in the synthesis of one or more globin chains resulting in an unbalanced synthesis of globin chains and a decreased hemoglobin production

12

Beta thalaseemia major

- decreased beta globin

- decreased Hg/cell

- microcytic hypochromic RBCs

- anemia

- bone marrow expands (xray of head)

- mediterranean heritage

13

Beta thalassemia

  - decreased beta globin synthesis. 

MAJOR (homozygous)

- severe anemia, hepatoslenomegaly, hypercellular marrow, bone changes, iron overload, infections, early death if untreated

Rx: transfucion, iron chelation

MINOR 

- mild anemia or symptomatic lab finding, may worsen with infections or pregnancy

Rx: genetic counseling, prenatal dx

14

alpha thalassemia

- decreased alpha globin synthesis

- usually oriental or asian

- 2 alleles for alpha chain synthesis (4 gene)

Hemoglobin H disease

- Hg H is a tetramer of beta chains. Precipitate in RBCs as intra-erythrocytic inclusions, hemolytic anemia. 

- Micro/hypo cytic, target cells

- only one good alpha gene

15

Enzymopathies

- G6PD deficiency

- pyruvate kinase deficiency

- hemolytic anemias caused by other derangement of the Embden-Meyerhoff pathawy (gycolysis)

- abnormalities of nucleotide metabolism

16

Erythrocyte infections

- malaria

- babesiolsis

- other prtazoal infections

- bartonellosis

17

intravascular vs extravascular RBC destruction

intravascular: RBCs destroyed within he peripheral blood circulation. May be due to direct lysis by the late components of complement , by toxins and oxidizing agents, mechanical trauma to RBCs.

 

Extravascular: RBCs destroyed outside of blood vessels. Usually refers to destruction by macrophages in spleen and liver

18

Intracorpuscular vs extracorpuscular 

intracorpuscular: an abnormality in RBC itself, leading to hemolysis

 

extracorpuscular: factor within plasma or external to the RBC which leads to hemolysis