Heme/Onc Flashcards
Manifestations of CO poisoning
CO displaces oxygen on hemoglobin
treat with 100% oxygen, possibly in a hyperbaric chamber
AMS
Cherry-red lips
Pulse-ox normal
microcytic anemias
IDA lead poisoning chronic disease sideroblastic thalassemia
normocytic anemias
hemolytic anemia
chronic disease
hypovolemia
macrocytic anemia
folate deficiency
B12 deficiency
liver disease
alcohol abuse
Mean RBC lifespan
120 days
hemolysis
intrinsic- defect intrinsic to cell
extrinsic
H and P:
pale, jaundice, hepatosplenomegaly, brown urine
Labs: decreased H/H increased retic count increased indirect bilirubin increased LDH normal MCV decreased serum haptoglobun
Coombs test for autoimmune abs
Peripheral blood smear:
schistocytes
spherocytes
Burr cells
Types of hemolytic anemia Drug- induced immune mechanical G6PD deficiency
COOMBs test
coomb’s reagent is rabit IgM against human IgG or complement, so that red cells that are bound by auto-immune factors will agglutinate in presence of reagent
direct test looks at patient red cells (reagent mixed with patient RBCs, agglutination- RBCs coated with IgG and complement)
antibodies on the RBCs may be due to warm or cold agglutinins
Warm= IgG (agglutinate at body temp)
Cold= IgM (mycoplasma, EBV), only agglutinate in cold environment
indirect test looks at patient plasmsa: mix serum with type O RBCs, and then with Coombs’ reagent. Agglutination if anti-RBC antibodies in serum
Drug- induced (coombs positive) hemolytic anemia
- PCN
- methyldopa
- quinidine (and quinine)
- cephalosporins
- NSAIDs
Immune hemylotic anemia
warm agglutinins or cold agglutinins
Associations:
EBV, mycoplasma pneumoniae, HIV
Treatment:
avoid cold exposure
steroids
splenectomy
Mechanical hemolytic anemia
turbulent blood flow
prosthetic heart valve
schistocytes
Hereditary spherocytosis
Genetic defect of red cell membranes, resulting in spherical red cells
characteristic findings:
- jaundice and gallstones
- splenomegaly
- anemia with reticulocytosis and increased MCHC (mean corpuscular hemoglobin concentration)
- high incidence of pseudohyperkalemia as RBCs lyse after blood draw and intracellular potassium leaks
- peripheral smear reveals spherocytes
- positive osmotic fragility test
What is the treatment?
- folic acid 1mg daily
- red cell transfucions in cases of extreme anemia
- splenectomy in moderate to severe disease
G6PD deficiency
Spleen Purges Nasty Inclusions From Damaged Cells
G6PD repairs oxidative damage to RBCs. Without it the body is prone to hemolysis
Spleen Purges Nasty Inclusions From Damaged Cells
Sulfonamides Primaquine Nitrofurantoin ING Fava beans Dapsone Chloroquine
PBS:
bite cells
Heinz bodies
Diagnosis:
decreased G6PD activity
fatigue begins within days of ingesting oxidants
Treatment:
antioxidants
transfusions
severer form affects mediterranean patients
milder affects blacks
Why is serum haptoglobin decreased in hemolytic anemia
Why is LDH increased
Haptoglobin binds free hemoglobin in the blood
Haptoglobin-hemoglobin complex is removed from circulation by the spleen
LDH is found inside RBCs
When RBCs lyse, LDH is released into circulation
G6PD
enzyme involved in pentose phosphate pathway
maintains glutathione in RBCs, which is neded to protect RBCs from oxidative damage
deficiency is x- linked recessive non-immune hemolytic anemia
stressors include infection, drugs, fava beans
Iron deficiency anemia
most common anemia
blood loss
poor iron intake
poor iron absorption
acutely, after blood loss the H/H will be normal. H/H won’t drop until after dilution
The new red cells have less iron, so they’re smaller than normal (hypochromic and microcytic with central pallor)
pregnancy
kids can have iron- fortified cereal after 6 months of age due to inadequate intake
history: fatigue, weakness, dyspnea, pica, restelss legs
exam: pallor, tachycardia, tachypnea. angular chelitis, spooning of the nails (concave)
Treatment: iron supplements
determine cause of iron loss
elderly, suspect colon cancer and pursue colonoscopy
Labs:
low serum iron
low serum ferritin
increased TIBC (directly proportional to transferrin), which is the iron transport protein
iron:TIBC ratio is decreased (
ferritin
storage form of iron, low in IDA
elevated in hemochromatosis
increased or elevated in anemia of chronic disease
normal in lead poisoning
increased in sideroblastic anemia
normal in thalassemia
transferrin
protein that transports iron in the blood
high in iron deficiency anemia, when your body wants to bind up iron and transport it where it needs to go
decreased in anemia of chronic disease
normal in lead poisoning
decreased in sideroblastic anemia
normal in thalassemia
Anemia of chronic disease
decreased serum iron
increased or normal ferritin
decreased TIBC
iron:TIBC ratio is normal or high (>18%)
Lead poisoning
serum iron is normal or increased
ferritin and TIBC are normal
Sideroblastic anemia
increased serum iron
increased serum ferritin
decreased TIBC
ringed sideroblasts build up in erythroblast, RBC precursors
seen in the bone marrow
Thalassemia
increased serum iron
normal ferritin
normal transferrin and TIBC
lead poisoning anemia
fatigue, weakness crampy abdominal pain joint pain HA short-term memory loss lead lines on gums peripheral neuropathy
Labs:
decreased MCV
peripheral blood smear: basophilic stippling (basophilic dots, granules of denatured RNA all over the cell) -lead poisoning -thalassemia -alcohol use
no central pallor
Treatment:
adults- EDTA, succimer
children- EDTA, succimer, dimercaprol if severe
Megaloblastic anemia
impaired DNA synthesis B12 deficiency folate deficiency (suspect in elderly with poor nutrition, and alcoholism, drug induced- phenytoin) hypersegmented PMN (more than 6 lobes)
H and P: poor nutrition inflammation of the tongue (glossitis) no neurologic symptoms How do we diagnose folate deficiency anemia?
Just give PO folate supplements anyway
To look at folate levels over time, check RBC folate level
What test gives a measure of RBC folate level over time
RBC folate level
B12 deficiency anemia
pernicious anemia- autoantibodies attack gastric parietal cells in the stomach
so that the body can’t make IF
inadequate B12 intake (vegetarian)
Note: folate insufficiency develops a lot more quickly than B12 deficiency
Resection of the ileum
Bacterial overgrowth
Diphyllobothrium latum infection (fish tapeworm)
H and P peripheral neuropathy paresthesias ataxia loss of vibration sense dementia
labs:
megaloblastic anemia
decreased B12 levels
high serum MMA and homocysteine (intermediate byproducts that build up with B12 is insufficient)
Schilling test (out-dated)
Treatment:
- IM B12
- dietary B12 supplements
- Intranasal B12
Anemia of chronic disease
Anemia in patients with chronic inflammatory states
DM
defect in iron mobilization and utilization
total body iron content is normal
serum iron levels may be low
Treatment:
treat the underlying disorder
supplemental erythropoietin to hgb 11 or 12
Aplastic anemia
pancytopenia from bone marrow failure (leuopenia and thrombocytopenia as well)
Causes: radiation drugs toxins viral infection (EBV, HIV, parvovirus) SCD- parvo B19 aplastic crisis idiopathic congenital
H and P
anemia (weakness, pallor, fatigue)
leukopenia (persistent infections)
thrombocytopenia (poor clotting, easy bruising, petechiae)
Labs: pancytopenia
hypocellularity
IH: fatty infiltration, with aplastic anemia
Treatment:
address underlying cause
bone marrow transplant
worse the older you get
What conditions are associated with schistocytes (fragmented RBCs)
hemolytic anemia
DIC, TTP, HUS
Acanthocytes (spur cells)
abetalipoproteinemia
Echinocytes (burr cells)
uremia, hemolysis
Bite cells
G6PD deficiency
it’s macrophages that bite the Heinz bodies
Basophilic stippling of RBCs
lead poisoning
peripheral neuropathy + ringed sideroblasts
lead poisoning
hypersegmented PMNs
megaloblastic anemia
Heinz bodies (denatured hgb in RBC)
G6PD deficiency
Sideroblastic anemia
anemia due to defects in the heme synthesis pathway
May be inherited (genetic) or acquired (alcohol abuse, INH, lead poison, zinc tox, copperdeficiency)
High RDW
MCV low, hypochromic
sideroblasts are normal nucleated RBC precursors with visible iron granules in their cytoplasm, found in the bone marrow
Ringed sideroblasts, which have iron granules surrounding the nucleus, are NOT normal.
Treatment: Supplement vitamin B6 (pyridoxine) Address underlying cause, stop alcohol Transfusions Erythropoietin Deferoxamine or phlebotomy if patient is iron-overloaded
myelodysplasia with ringed sideroblasts also exists and can progress to acute leukemia
Alpha Thalessemia
alpha thalessemia- defect in alpha globin
more prevalent in patients of African and Asian descent
alpha thalessemia minima: 1 mutated allele, asymptomatic
alpha thal minor or trait: 2 mutated alleles, asymptomatic
HbH disease: 3 mutated alleles a ton of beta globin made of 4 beta globin molecules microcytosis chronic hemolysis
Hemoglobin Bart’s: 4 mutated alleles, incompatible with life
made of 4 gamma globins
hydrops fetalis (leads to death)