RBC basics + erythropoiesis Flashcards
no nucleus
biconcave (large SA for gas exchange) and flexible: both due to cytoskeleton protein SPECTRIN
rely on glucose for energy (no mito): 90% is aneorbic metabolism from glucose → lactate, 10% is HMP shunt metabolism
life span: 120 days
erythrocytes
complication of loss of biconcave RBC shape
sickle cell disease
hereditary spherocytosis
viscous → sludging in capillaries
deficient pyruvate kinase (enzyme in glycolysis pathway)
no energy to RBC → RBC hemolyisis
anisocytosis
RBC of varying sizes
poikilocytosis
RBC of varying shapes
polycythemia/erythrocytosis
too many RBCs
reticulocytosis
immature RBCs: when BM is producing more → leak out into blood
basophilic stippling
inhibition of enzyme that degrades RNA
lead poisioning causes
basophilic stippling
echinocyte (burr cell)
REGULAR, uniform spikes over surface
uremia (renal failure) causes
echinocyte (burr cell)
acanthocyte (spur cell)
IRREGULAR, spikes over surface
both these cause:
liver disease
abetalipoproteinemia (state of cholesterol dysregulation)
acanthocyte (spur cell)
spherocyte
lose biconcave shape
hereditary spherocytosis causes
spherocytes
schistocytes
fragmented RBCs
pathologic intravascular clotting (fibrin in blood vessels) → RBC sliced by fibrin (microangiopathic hemolytic anemia):
DIC
TTP/HUS
schistocytes
THAL Thalassemia Hemoglobin C disease Asplenia Liver disease
target cells
pathologic RBCs seen in liver disease
target cells
acanthocytes (spur cells)
sickle cells
crescent-shaped
Howell-Jolly body
basophilic remnant of nucleus in RBC
no splenic macrophage to remove it
asplenia (due to trauma or ITP treatment, complication of sickle cell disease- infarcted spleen) causes
target cells
howel-jolly body
complication of sickle cell disease
infarction of spleen
Heinz bodies (looks like Howell Jolly bodies)
oxidation of hemoglobin → denatured hemoglobin precipitates in RBC →splenic macrophages bite it → bite cells
bite cells (degmacyte)
splenic macrophages bite denatured hemoglobin (Heinz body) out of RBC
G6PD deficiency: can’t go through HMP shunt → no NADPH produced → no reduction of glutathione → no detoxification of free radicals → Hb is oxidized → Heinz body + bite cells
sensitive to drugs that cause oxidative damage (cause Heinz bodies + bite cells)
Spleen Purges Nasty Inclusions from Damaged Cells Sulfonamides Primaquine Nitrofurantoin Isoniazid Fava beans Dapsone Chloroquine
heinz body vs howell-jolly body
howell-jolly body: remnant of nucleus (only 1 per cell) heinz body (many per cell)
myelofibrosis (BM infiltration)
teardrop cells
hereditary elliptocytosis
elliptocytes “pencil cell, cigar cell”
sideroblast
nucleated red cell precursor
granules of iron in mitochondria
found in BM (normal finding)
disorders of heme synthesis
anemia +
ringed sideroblasts in BM = sideroblastic anemia
ringed sideroblasts
sideroblast can’t use iron stored in mitochondria →excess iron granules form ring around nucleus
found in BM
causes of sideroblastic anemia
drugs
chronic alcohol use
myelodysplastic syndromes
transfusion with incompatible blood type
Ab-mediated type II HSR: circulating Ab binding to RBC antigens → hemolysis, fever, shock, kidney failure, death
1 cause of transfusion reactions
medical personnel
Rh-D (-) mom only have antibodies to Rh-D due to exposure to Rh-D + baby’s (during delivery/trauma of first pregnancy, no problems)
more abundant maternal Abs (anti-Rh-D = IgG cross placenta) to fetal Rh-D + baby (2+ pregnancy)
erythroblastosis fetalis
anemia due to hemolysis of RBCs by maternal Abs → release Hb → bilirubin
jaundice → possible kernicterus
hydrops fetalis: generalized fetal edema
intrauterine death
erythroblastosis fetalis
prevent of erthryoblastosis fetalis in Rh- mom
anti-Rh-D immunoglobulin (bind to fetal RBC and hide from mom's Ab) at: 28 wks any traumatic event (MVA) any abortion/miscarriage within 3 days of delivery
look at ABO blood types
k
type AB blood
express A + B antigens on RBC surface
NO A or B antibodies → universal RECIPIENT of RBCs (only blood type that can receive AB)
type O blood
no antigens on RBC surface
A + B antibodies in blood→ universal DONOR (only can receive type O)
abdominal pain: neuropathic: intermediate heme precursors are neurotoxic
“port wine” urine: excess heme precursors in blood, spill into urine
polyneuropathy
psych disturbances
precipitated by drugs: barbiturates, seizure drugs, rifampin, metoclopramide
acute intermittent porphyria
treatment of acute intermittent porphyria
both inhibit ALA synthase (RLE):
glucose
heme
blistering of skin in sun (esp hands): photosensitivity "tea-colored" urine hypertrichosis: excessive hair growth facial hyperpigmentation ↑LFTs: AST, ALT associated with hep C + alcoholism
porphyria cutanea tarda: most common form of porphyria
think of homeless man
porphobilinogen deaminase deficient in
acute intermittent porphyria
uroporphyrinogen decarboxylase deficient in
porphyria cutanea tarda
affects ALA-dehydratase + ferrochelatase
lead poisioning
child causes:
exposed to lead paint (
lead poisioning
adult causes:
factory with lead
lead poisioning
adult with neuro sx:
headache
memory loss
demyelination
lead poisioning
CNS toxicity:
encephalopathy
memory loss
delerium
mental deterioration: learning disabilities
headaches
foot/wrist drop
lead lines (dark blue/black) on gingiva: burton lines
lead lines on long bones along metaphyses (child)
colicky ab pain
renal failure
microcytic anemia with basophilic stippling: denatured rRNA in cell
lead poisioning
treatment of lead poisioning
child or adults: EDTA or succimer
child with severe toxicity: dimercaprol + succimer
causes of polycythemia
1) polycythemia vera: monoclonal proliferation of RBCs
2) chronic hypoxia (pulm disease/COPD, sleep apnea, cyanotic heart disease, high altitudes): kidneys recognize ↓ O2 saturation→ ↑ EPO→ ↑ RBC → ↑ O2 carrying capacity
3) ↑ ectopic epo:
EPO-producing tumor
4) trisomy 21 (60% at birth)
4 EPO producing tumors
Potentially Really High Hematocrit Pheochromocytoma Renal cell carcinoma Hepatocellular carcinoma Hemangioblastoma (vascular CNS tumor)
