RBC and anemia 0503 Flashcards
acanthocyte (spur cell)
liver disease
abetalipoproteinemia
basophilic stippling
Lead poisoning
Thalassemia
Anemia of Chronic Disease
“Love The Angry Crawfish of Drew”
bite cell
G6PD deficiency
elliptocyte
hereditary elliptocytosis
macro-ovalocyte
megaloblastic anemia (w/ hypersegmented neutrophils) marrow failure
ringed sideroblasts
sideroblastic anemia
schistocyte (helmet cell)
microangiopathic anemia: TTP, HUS
DIC
traumatic hemolysis
sickle cell
sickle cell anemia
spherocyte
hereditary spherocytosis
autoimmune hemolysis
tear drop cell
bone marrow infiltration - MYELOFIBROSIS
target cell
HbC disease
Asplenia
Liver disease
Thalassemia
“HALT, said the hunter to his target”
Heinz bodies
alpha thalassemia
G6PD deficiency
Heinz bodies pathogenesis
oxidation of iron from ferrous to ferric form leads to denatured Hb precipitation and damage to RBC membrane – leads to bite cells
Howell-Jolly bodies
functional hyposplenia
asplenia
Howell-Jolly bodies pathogenesis
basophilic nuclear remnants found in RBCs (one obvious darker spot)
anemia presentation
signs of hypoxia: weakness, fatigue, dyspnea pale conjunctiva and skin* HA, lightheaded angina (esp w/ CAD)
cause of microcytic anemia
decreased production of Hb.
extra RBC division tries to maintain Hb conc.
- Fe deficiency anemia
- thalassemias
- lead poisoning
- sideroblastic anemia
- ACD
where does Fe absorption occur?
duodenum
ferroportin
allows Fe across enterocyte membrane into bld
transferrin
binds and transports Fe in bld, deliver to storage sites
ferritin
stores Fe in macrophages, liver, BM (prevent from free radical formation)
as ferritin decreases, what value increases?
TIBC - increased transferrin molecules in bld to find more Fe
presentation of Fe deficiency anemia
anemia
koilonychia (spoon nails)
pica
causes of Fe deficiency anemia
(decreased heme synth)
chronic bleeding- GI loss, menorrhagia
malnutrition/malabsorption
increased demand (preg)
Plummer Vinson syndrome
- Fe deficiency anemia
- esophageal webs (dysphagia)
- atrophic glossitis (beefy red tongue)
cause of alpha thal
alpha globin gene deletion
= decreased synth of alpha globin
(4 genes present at chromo 16)
alpha thal population
Asians
Africans
alpha thal 4 gene deletion
Hb Barts (gamma-4).
hydrops fetalis.
fatal in utero.
alpha thal 3 gene deletion
HbH disease (beta-4). tetramers damage RBCs.
alpha thal 1 or 2 gene deletion
no significant anemia
cause of beta thal
POINT mutation in splice sites and promoter regions of beta globin gene
= decreased synth of beta globin
beta thal population
Mediterranean
beta thal minor
heterozygote.
beta chain is UNDERPRODUCED.
mildest form.
usually asymptomatic.
beta thal minor DX
TARGET CELLS.
electrophoresis: increased HbA2 > 3.5% (alpha-2, delta-2). increased HbF (alpha-2, gamma-2). decreased HbA1 (alpha-2, beta-2).
beta thal major
homozygous.
beta chain is ABSENT.
beta thal major SX
severe anemia requiring TRANSFUSION (secondary hemochromatosis).
marrow expansion (erythroid hyperplasia). skel deformities.
crew cut on skull XR.
chipmunk facies.
beta thal major DX
TARGET CELLS.
electrophoresis: little or no HbA1 (alpha-2, beta-2). increased HbF (alpha-2, gamma-2).
HbS/beta thal heterozygote
mild to moderate sickle cell dz depending on amt of beta globin production
enzymes inhibited by lead
ALA dehydratase
ferrochelatase
lead poisoning
lead inhibits enzymes leading to decreased heme synth.
also inhibits RNA degradation.
SX of lead poisoning
“LEAD”
Lead lines on gingiva (Burton’s lines) and on epiphyses of long bones on XR
Encephalopathy and Erythrocyte basophilic stippling
Abdominal colic and sideroblastic Anemia
Drops - wrist and foot
what is basophilic stippling?
aggregation of ribosomes in RBC
TX of lead poisoning
1st line: Dimercaprol and EDTA
for kids: succimer
sideroblastic anemia
defective protoporphyrin synth
= defective heme synth
*reminder: heme = proto + iron
ringed sideroblasts
erythroid precursor with IRON-laden mitochondria around nucleus
*heme is formed in mito. lack of proto leads to iron being trapped in mito.
hereditary sideroblastic anemia
X-linked defect in ALA synthase
acquired (reversible) sideroblastic anemia
alcohol
lead
LABS in sideroblastic anemia
increase serum Fe
increase ferritin
normal (decrease) TIBC
TX of sideroblastic anemia
pyridoxine (B6) - cofactor for ALA synthase
megaloblastic anemia
impaired DNA synthesis: maturation of nucleus is delayed relative to cytoplasm (one less division than normal)
ineffective erythropoiesis: pancytopenia.
megaloblastic anemia
FOLATE deficiency
due to: malnutrition (ALCOHOLICS) malabsorption - jejunum impaired metab (MTX, TMP) increased requirement (preg, hemolytic anemia)
findings in megaloblastic anemia
FOLATE deficiency
hypersegmented neutrophils. glossitis. decreased serum folate. increased serum homocysteine. NORMAL METHYLMALONIC ACID.
megaloblastic anemia
B12 deficiency
due to: pernicious anemia insufficient intake (strict vegans) malabsorption (Crohns) Diphyllobothrium latum (fish tapeworm)
pernicious anemia
most common cause of B12 def.
autoimmune destruction of gastric parietal cells that make intrinsic factor.
intrinsic factor def = less B12 absorption in ileum.
findings in megaloblastic anemia
B12 deficiency
hypersegmented neutrophils. glossitis. NEURO SX. decreased serum B12. increased serum homocysteine. INCREASED METHYLMALONIC ACID.
NEURO problems in B12 deficiency
subacute combined degeneration (B12 is involved in fatty acid pathways - myelinization)
- peripheral neuropathy w/ sensorimotor dysfunction
- posterior columns (vibration, proprioception)
- lateral corticospinal (spasticity)
4 dementia
TX of B12 deficiency
parenteral B12
nonmegaloblastic macrocytic anemia
due to: liver disease alcoholism reticulocytosis (increase MCV) metab d/o: congenital deficiency in purine or pyrimidine synthesis drugs: 5-FU, AZT, hydroxyurea
nonhemolytic normocytic anemias
- anemia of chronic dz
- aplastic anemia
- kidney dz
UNDERPRODUCTION
corrected retic count < 3%.
anemia of chronic disease
inflammation = increased HEPCIDIN from liver.
hepcidin binds ferroportin on enterocytes and macrophages - inhibit Fe transport. decreased Fe release from macrophages (more storage).
increase ferritin
decrease TIBC
decrease serum Fe
*can become microcytic, hypochromic over time
aplastic anemia causes
due to failure or destruction of myeloid stem cells:
- radiation, drugs: benzene, chloramphenicol, alkylating agents, antimetabolites
- viral agents: parvo B19, EBV, HIV, HCV
- Fanconi anemia (DNA repair defect)
- idiopathic: autoimm? primary stem cell defect? may follow acute hepatitis
aplastic anemia findings
PANCYTOPENIA- severe anemia, neutropenia, thrombocytopenia.
hypocellular BM with FATTY infiltration.
SX: fatigue, malaise, pallor, purpura, mucosal bleeding, petechiae, infx.
aplastic anemia TX
withdraw offending agent.
IMMUNOSUPPRESSION (antithymocyte globulin, cyclosporine)
allogeneic BMT.
RBC and plt transfusion.
G-CSF or GM-CSF.
anemia due to kidney disease
decreased EPO production =
decreased hematopoiesis
intravascular hemolysis findings
destruction of RBCs within vessels.
decrease haptoglobin (bind all the free Hb for reprocessing). increase LDH.
SX: hemoglobinemia, hemoglobinuria
extravascular hemolysis findings
splenic macrophages destroy RBC.
increase LDH
increase unconj. bilirubin (from proto)
SX: marrow hyperplasia
splenomegaly
jaundice
hemolytic normocytic anemia
PERIPHERAL RBC DESTRUCTION.
corrected retic count > 3%.
hereditary spherocytosis
intrinsic hemolytic anemia.
extravascular hemolysis.
defect in proteins that interact with RBC memb skeleton and plasma memb - ankyrin, spectrin, band 3, protein 4.2
spherocytes
in HS: less membrane causes small and round RBCs with no central pallor.
prematurely removed by spleen.
hereditary spherocytosis LAB
increase MCHC**
increase RDW
DX: osmotic fragility test
hereditary spherocytosis SX
splenomegaly
jaundice
aplastic crisis (B19 infx)
hereditary spherocytosis TX
splenectomy:
HOWELL-JOLLY BODIES present after splenectomy
G6PD deficiency
intrinsic hemolytic anemia.
both extra and intravascular hemolysis.
X-linked defect in G6PD.
normal G6PD function
G6PD generates NADPH which is needed to reduce GLUTATHIONE for antioxidant activity.
RBCs become susceptible to oxidant stress when glutathione can’t be reduced.
causes of hemolytic episodes in G6PD def
oxidant stress: sulfa drugs primaquine dapsone infection fava beans
G6PD def SX
back pain
hemoglobinuria a few days later
G6PD LAB
RBCs with Heinz bodies. BITE CELLS (created as splenic macros remove Heinz bodies).
pyruvate kinase deficiency
intrinsic hemolytic anemia.
extravasc hemolysis.
auto rec defect in pyruvate kinase.
decreased ATP = rigid RBCs.
*hemolytic anemia in newborn
HbC defect
intrinsic hemolytic anemia.
extravasc hemolysis.
Hb beta chain defect. missense mutation (chain mutation): glutamic acid replaced by lysine at pos 6.
HbSC
possess one of each mutant gene. milder disease than HbSS (sickle cell dz).
HbC defect LAB
lysine is more positive…
HbC is more positive.
moves more slowly on gel electrophoresis.
paroxysmal nocturnal hemoglobinuria
intrinsic hemolytic anemia.
intravasc hemolysis.
myeloid stem cell defect.
complement-mediatd RBC lysis.
impaired synth. of GPI anchor/decay accelerating factor (DAF) in RBC memb.
normal DAF (CD55)
binds to RBC via GPI.
inhibits C3 convertase.
PNH LAB
increased urine hemosiderin.
deficient in CD55 (and CD59).
PNH SX
episodes occur at night - dark urine in the morning.
PNH complications
thrombosis - PLATELETS are also destroyed. activate coag cascade and induce thrombosis.
sickle cell anemia
intrinsic hemolytic anemia.
both extra and intravasc hemolysis.
AR HbS point mutation causes single AA replacement in beta chain - glutamic acid replaced by valine at pos6.
sickle cell pathogenesis
low O2, dehydration (low bld vol), or low pH precipitate sickling - deoxy HbS POLYMERIZES and causes sickle shape.
RBCs with damaged memo are removed/destroyed. results in anemia, vaso-occlusive dz.
sickle cell in newborns
newborns ASYMPTOMATIC in first few months - HbF is protective against sickling. newborns have more HbF, less HbS.
sickle cell and malaria
HETEROZYGOTES (sickle cell trait) have resistance to malaria.
8% of Af Am carry HbS trait
sickle cell presentation
anemia
fatigue
splenomegaly
CREW CUT on skull XR, chipmunk facies (marrow expansion to compensate)
complications w/ sickle cell dz
- aplastic crisis (B19)
- autosplenectomy
- splenic sequestration crisis
- salmonella osteomyelitis
- painful vaso-occlusive crisis
- renal papillary necrosis
autosplenectomy in sickle cell
shrunken, fibrotic spleen.
functional splenic dysfunction occurs in early childhood.
leads to:
increased infx with encapsulated orgs.
Howell-Jolly bodies.
vaso-occlusive crises in sickle cell
DACTYLITIS: painful hand and feet swelling.
ACUTE CHEST SYNDROME: chest pain, SOB, lung infiltrates.
renal papillary necrosis in sickle cell
due to low O2 in papilla.
medullary infarcts - MICROSCOPIC HEMATURIA.
sickle cell DX
Hb electrophoresis - HbS is more hydrophobic (POLAR). moves more slowly to anode than HbA does.
sickle cell TX
- hydroxyurea: increased HbF
2. BM transplant
autoimmune hemolytic anemia (AIHA)
extrinsic hemolytic anemia.
Ab-mediated destruction of RBCs.
many are idiopathic.
Coombs positive.
present w/ erythroblastosis fetalis.
erythroblastosis fetalis
seen in newborns due to Rh or other bld Ag incompatibility - mom’s Abs attack fetal RBCs.
direct Coombs test
asks: are there RBCs already bound by Ig?
add anti-Ig to pt’s RBCs. agglutination occurs if RBCs are already coated with Ig.
indirect Coombs test
asks: is there Ig in the pt’s serum?
add anti-Ig with test RBCs to pt serum. agglutination occurs if serum Ig is present.
AIHA: warm agglutinin
IgG
chronic anemia seen in SLE, CLL, certain drugs (alpha methyldopa)
AIHA: cold agglutinin
IgM (Cold ice cream, Mmmm)
acute anemia triggered by cold.
seen in CLL, mycoplasma pneumonia infxs, infectious mononucleosis.
microangiopathic anemia
extrinsic hemolytic anemia.
intravasc hemolysis.
RBCs are damaged when passing through obstructed or narrowed vessel lumen.
diseases assoc. with microangiopathic anemia
DIC TTP HUS SLE malignant HTN
RBCs in microangiopathic anemia
SCHISTOCYTES (helmet cells) due to mechanical destruction
macroangiopathic anemia
extrinsic hemolytic anemia.
secondary to mech destruction with prosthetic heart valves and aortic stenosis.
SCHISTOCYTES.
anemia in infections
extrinsic hemolytic anemia.
increased destruction of RBCs.
ex: malaria, Babesia
porphyrias
defective heme synthesis leading to accumulation of heme precursors
*most common: PCT
lead poisoning
enz: ALA dehydratase, ferrochelatase
accumulated substrate: protoporphyrin (in bld)
sx: microcytic anemia, GI/kidney dz. abd pain, blue pigment (gingiva).
kids: mental deterioration.
adults: HA, memory loss, demyelination.
source of lead poisoning
kids: exposure to lead paint
adults: environmental exposure (battery, ammunition, radiator factory)
acute intermittent porphyria
enz: porphobilinogen deaminase
accumulated substrate: porphobilinogen, ALA, uroporphyrin (porphobilinogen in urine)
AIP SX
Painful abd Pink urine (red wine) - darkens upon standing Polyneuropathy Psychological disturbances Precipitated by drugs
AIP TX
glucose and heme, which inhibit ALA synthase upstream
porphyria cutanea tarda
enz: uroporphyrinogen decarboxylase
accumulated substrate: uroporphyrin - tea colored urine
other sx: blistering cutaneous photosensitivity.
*most common porphyria
