Anemias Flashcards
(40 cards)
Iron deficiency anemia
Microcytic
hypochromic
Poor iron intake
Blood loss: menstruation, colon cancer, peptic ulcer
Increased iron demand in pregnancy
Assoc: plummer vinson sn -iron deficiency anemia -esophageal webs -dysphagia \+/- atrophic glossitis
Alpha thalassemia
Defect in globin synthesis
Alpha on Chr 16, 4 alleles
1 abnl allele – no anemia
2 abnormal alleles
- a-thalaseemia trait/minor
- no anemia
3 abnl alleles – 1 normal alpha gene
-> HbH – beta 4
4 abnl allels – incompatible with life
Fetus: hemoglobin Barts (gamma 4)
-> generalized fetal edema – hydrops fetalis
-> death
Beta thalassemia
Defect in beta globin gene – 2 alleles
Mediterranean populations
Minor: decreased beta globin
- minimal anemia
- increased HbA2 – a2delta2
Major: absent beta globin
- severe anemia
- blood transfusion -> hemochromatosis (tx: deferoxamine – iron chelator)
- Peripheral smear: target cells
- BM hyperplasia
- XR: crew cut on skull XR
- > chipmunk facies
- increased HbF (alpha 2 gamma 2)
Anemia of chronic disease
Defective iron utilization Assoc w/ chronic inflammation -RA -Chronic infections -Malignancy
iron trapped in M0
normal or elevated ferritin
low serum iron
Normocytic first -> microcytic hypochromic
Iron deficiency anemia iron studies
Serum Iron: low
TIBC: high
Ferritin: low
% transferrin saturation: low (below 12%)
Anemia of chronic disease iron studies
Serum Iron: low
TIBC: not iron deficient - low
Ferritin: nl or high
% transferrin saturation: nl (above 18%)
Hemochromatosis iron studies
Serum Iron: high
TIBC: low
Ferritin: high (normal r/o hemochromatosis)
% transferrin saturation: high
Sideroblastic anemia iron studies
Serum Iron: high
TIBC: low
Ferritin: high
% transferrin saturation: nl or high
Megaloblastic anemia
B12 deficiency (vegans, malabsorption (pernicious anemia, crohn’s dz), diphyllobothrium latum)
Folate deficiency (malnutrition, malabsorption, MTX, TMP, high folate req (hemolytic anemia, pregnancy))
Impaired DNA synthesis
Hypersegmented neutrophils >6 lobes
Glossitis
Elevated homocysteine
B12: neurologic defects -> high methylmelonic acid (MMA)
Other cause:
Orotic aciduria: deficient UMP synthesis -> pyrimidine synthesis impaired
-orotic acid in urine
no hyperammonemia
Nonmegaloblastic macrocytic anemia
Liver dz
Alcoholism
Drugs – 5FU, zidovudine, hydroxyurea
Causes of non-hemolytic normocytic anemia
Anemia of chronic disease
Renal failure
Aplastic anemia
non-hemolytic normocytic anemia - Renal failure
No EPO production
EPO injections needed
non-hemolytic normocytic anemia – anemia of chronic dz
Inflammatory mediates (IL6)
- > liver production of hepcidin
- inhibits ferroportin
- iron trapped in M0
labs:
low serum iorn
lower TIBC
nl or high ferritin
Non-hemolytic normocytic anemia – aplastic anemia
Pancytopenia
Histo: hypocellular BM w/ fatty infiltration
Anemia: fatigue, malaise, palor
Thrombocytopenia: purpura, petechiae, bleeding
Leukopenia: infections
d/t radiation, benzene Chloramphenicol Cancer drugs Parvo B19, EBV, HIV, esp sickle cell Fanconi anemia Idiopathic after acute hepatitis
Tx: stop offending agent Immunosuppresants Transfusions G-CSF, GM-CSF BM transplant
Intravascular hemolysis
Low haptoglobin
High LDH – high in RBCs
Autoimmune hemolytic anemia
Paroxysmal nocturnal hemoglobinuria
Mechanical destruction of RBCs
G6PD deficiency
Extravascular hemolysis
High LDH High unconjugated (indirect) bilirubin
Hereditary spherocytosis G6PD deficiency Pyruvate kinase deficiency Sickle cell dz Hemoglobin C dz
Hereditary spherocytosis
Ankryin
Spectrin
Band 3, Protein 4.2 : link ankryin to cytoskeleton to membrane
Lack central pallor, smaller
Increased MCHC – same amount of Hb in smaller cell = more concentrated
High RDW – vary in size
Spleen removes abnl cells -> splenomegaly
Jaundice
Pigmented gallstones
Aplastic crisis d/t Parvovirus B19 infection
Test: omotic fragility test
-lyse more readily in hypotonic solution at any given [NaCl]
eosin 5 maleimide: normally binds band 3, reduced binding = band 3 deficiency
Tx: Supportive Folic acid RBC transfusion Splectomy -> Howell –Jolly bodies
G6PD deficiency
Sensitive to oxidative stress -> hemolysis and back pain
Heinz body -> bite cells
Drugs: Fava beans Isoniazid Nitrofurantoin Dapsone Sulfonamides Primaquine Aspirin – high dose Ibuprofen Napthalene Chloroquine
Pyruvate kinase deficiency
Glycolytic enzyme deficiency
Can’t generate ATP, no Na+/K+ ATPase activity -> swelling and hemolysis
Paroxysmal nocturnal hemoglobinuria
Missing CD55 and CD59 surface markers
-> complement attack and lyses RBCs
Dx:
“Ham’s Test” – lysis at low pH – complement activates
Flow cytometry
Hemosiderinuria + thrombosis
HbC disease
Point mutation on beta globin gene
Glu -> Lys
-> hexagonal crystals
Heterozygous: asx
Homozygous: milder than sickle cell, hild hemolysis and splenomegalyq
SC disease
Heterozygous mutations
HbS mutation
HbC mutation
Milder than sickle cell dz
Sickle cell disease
HbS mutation
- point mutation on Chr 11 beta globin gene
- Glu -> Val at position 6 -> longer polymerase
sickling triggers:
hypoxemia
dehydration
acidosis
0.2% homozygous
Heterozygous (HbS trait) – 8% AA
-relative resistance to malaria
Newborns asx – more HgF
Complications: Splenic sequestration crisis Salmonella osteomyelitis Aplastic crises w/ Parvo B 19 Pain crisis – vasooclusion -> ischemia Dactylitis Acute Chest Sn Renal papillary necrosis
Skull XR: hair on end of skull, marrow hyperplasia “buzzcut”
Tx: hydroxyurea -> increased HbF
BM transplant
Splenic sequestration crisis
Complication of sickle cell disease
Infants and toddlers 2-3 yo
H and H drops
Wedge shaped infarct
-> autosplenectomy by 3-4 yo
increase risk of infection by encapsulated organisms
