Erythropoiesis Flashcards
Erythropoiesis in infant/childhood vs adulthood
Infants/kids: Entire skeleton Sternum Pelvis Ribs Cranial bones Vertebrae Long bones of leg
Adulthood: Axial skeleton Vertebrae Sternum Ribs Pelvis
Adult hemoglobin
HbA
Alpha 2 (Chr 10) Beta 2 (Chr 11)
Fetal hemoglobin
HbF
Alpha 2
Gamma 2
Gamma has lower affinity for 2,3 DPG, higher affinity to O2 than beta in adult
-allows transfer of O2 to fetus
Relative polycythemia
Low plasma volume
Normal number of RBC
Absolute polycythemia
Normal plasma volume
Elevated number RBCs
HbA
97% of normal hemoglobin
a2b2
HbA2
2% normal hemoglobin
a2d2 (delta)
HbA1c
Poorly controlled diabetes
A2b2-glucose
HbF
Fetal hemoglobin
a2 gamma2
Hb Gower
Embryonic hemoglobin
2 zeta, 2 epsilon
HbS
Sickle cell hemoglobin
A2Bs2
Glu->val in beta chain
HbC
Hemoglobin C disease
A2Bc2
Glu -> lys in beta chain
Hb Bart’s
Severe alpha thalassemia
Gamma4 – no alpha chains
HbH
Severe alpha thalassemia
Beta 4 – no alpha chains
Polycythemia vera
Monoclonal proliferation of RBCs
Benign neoplasm
Polycythemia/Erythrocytosis
Chronic hypoxia
- pulmonary dz
- OSA
- cyanotic heart dz
- high altitudes
inappropriate elevation of EPO
-EPO producing tumor
60% Downs at birth
EPO producing tumors
“Potentially Really High Hematocrit”
Pheochormocytoma
Renal cell carcinoma
Hepatocellular carcinoma
Hemangioblastoma
Draw out heme synthesis
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Acute intermittent porphyria
Deficient uroporphyrinogen-1-synthase
(porphobilinogen deaminase)
Abd pain – neuropathic
Port wine urine
Polyneuropathy
Psych disturbances
Triggered by drugs: Barbiturates Seizure durgs Rifampin Metoclopramide
Tx: glucose and heme to inhibit delta-ALA synthase (reduce heme synthesis)q
Porphyria cutanea tarda
MC
Deficient in uroporphyrinogen decarboxylase
Blistering of skin, photosensitivity –esp hands
Tea colored urine
Hypertrichosis
Facial hyperpigmentation
Assoc w/ Hep C and alcoholism
Lead poisoning
Microcytic anemia
Basophilic stippling
Neurologic manifestations
Block delta-ALA dehydratase and Ferrochelatase in heme synthesis pathway
Global encephalopathy: memory loss, delirium, mental deterioration
Foot/wrist drop
Lead lines – gingival – burton’s lines
-metaphyses
colicky abd pain
-> renal failure in adults
Adults: HA, memory loss, demyelinization
Tx:
EDTA, succimer
Severe in kids (elevated LFTs): dimercaprol + succimer
