Anemias Flashcards
What are the Microcytic anemias?
- Iron def
- ACD
- Thalassemias
- Lead poisoning
- Sideroblastic anemia
What are the Normocytic Nonhemolytic anemias?
- Anemia of chronic dz
- Aplastic anemia
- Chronic kidney dz
What are the Normocytic Intrinsic hemolytic anemias?
- Hereditary spherocytosis (RBC mem defect)
- G6PD, PK (RBC enzyme def)
- HbC
- Sickle cell anemia
- Paroxysmal nocturnal hemoglobinuria
What are the Macrocytic Megaloblastic anemias?
- Folate def
- B12 def
- Orotic aciduria
What are the Macrocytic Non-megaloblastic anemias?
- Liver dz
- Alcoholism
- Reticulocytosis
What are the Normocytic Extrinsic hemolytic anemias?
- Autoimmune
- Microangiopathic
- Macroangiopathic
- Infections
What is Microcytic hypochromatic anemia?
MCV <80fL
What causes iron def anemia?
Dec iron d/t chornic bleeding (GI loss, menorrhagia), malnutrition/absorption disorders or inc demand→ dec final step in heme synthesis
What are the findings in Iron def anemia?
- Dec iron
- Inc TIBC
- Dec ferritin
- Microcytosis
- Hypochromia
What is the triad of Plummer-Vinson synd?
- Iron def anemia
- Esophageal webs
- Atrophic glossitis
What is the defect in alpha-thalassemia?
Alpha-globulin gene mutations→ dec alpha-globin synthesis
Which deletion is prevalent in Asian pop w/ alpha-thalassemia?
Cis deletion
Which deletion is prevalent in African pop w/ alpha-thalassemias?
Trans deletion
What are the features of 4 gene deletion alpha thalassemia?
- No alpha globin
- Excess gamma-globin forms gamma 4 (Hb Barts)
- Incompatible with life–hydrops fetalis
What are the features of 3 gene deletion alpha thalassemia?
- HbH dz
- Very little alpha-globin
- Excess ß-globin forms ß4 (HbH)
What are the features of 1-2 gene deletion alpha thalassemia?
No clinically significant anemia
What causes ß-thalassemia?
Point mutations in splice sites & promoter sequences→ dec ß-globin synthesis
Which pop is ß-thalassemia prevalent in?
Mediterranean
What are the findings in ß-thalasemia minor?
- Heterozygote
- ß chain underproduced
- Dx confirmed by inc HbA2 (>3.5%) on electrophoresis
What are the findings in ß-thalassemia major?
- Homozygote
- ß chain is absent
- Marrow expansion
- Inc in HbF (alpha2gamma2)
What does absent ß chain produce?
Severe anemia requiring blood transfusion
(2° hemochromatosis)
What are the features of marrow expansion?
Skeletal deformities
- Chipmunk facies
- “Crew cut” on skull x-ray
What are the features of HbS/ß thalassemia heterozygote?
Mild to moderate sickle cell dz depending on amount of ß-globin production
What does lead poisoning lead to?
- Lead inhibits ferrochelatase & ALA dehydratase→ dec heme synthesis
- Also inhibits rRNA degradation causing RBC’s to reatin aggregates of rRNA (basophilic stippling)
What inc the risk of lead poisioning?
High risk in houses w/ chipped paint
What are the sx of lead poisoning?
- Lead lines on gingivae & metaphyses of long bones on x-ray
- Encephalopathy & erythrocyte basophilic stippling
- Abd colic & sideroblastic anemia
- Wrist & foot drop
What are Burton’s lines?
Lead lines on gingivae
What is the 1st line tx for lead poisoning?
Dimercaprol & EDTA
What is used for chelation in kids?
Succimer
What is the defect in Sideroblastic anemia?
Defect in heme synthesis
What is the defect in Hereditary Sideroblastic anemia?
X-linked defect in delta-ALA synthase gene
What are the reversible etiologies in Sideroblastic anemia?
Alcohol, led & isoniazid
What are the findings in Sideroblastic anemia?
- Ringed sideroblasts (w/ iron-laden mitochondria)
- Inc iron
- Normal TIBC
- Inc ferritin
What is the tx for Sideroblastic anemia?
Pyridoxine (B6 cofactor for delta-ALA synthase)
What is Megaloblastic anemia?
Impaired DNA synthesis→ maturation of nucleus delayed relative to maturation of cytoplasm
Ineffective ereythropoiesis→ pancytopenia
What are the etiologies of Folate deficiency?
- Malnutrition
- Malabsorption
- Antifolates
- Inc requirement
What are the findings in Folate deficiency?
- Hypersegmented neutrophils
- Glossitis
- Dec folate
- Inc homocysteine but normal methylmalonic acid
What are the etiologies of B12 deficiency (cobalamin)?
- Insufficient intake
- Malabsorption
- Pernicious anemia
- Diphyllobothrium latum
- Proton pump inhibitors
What are the findings in B12 def?
- Hypersegmented neutrophils
- Glossitis
- Dec B12
- Inc homocysteine
- Inc methylmalonic acid
What causes the neurologic sx in B12 def?
Subacute combined degeneration d/t involvement to B12 in fatty acid pathways & myelin synthesis
What are the neurologic sx in B12 def?
- Peripheral neuropathy w/ sensorimotor dysfunction
- Posterior columns (vibration/proprioception)
- Lateral corticospinal (spasticity)
- Dementia