RBC part 2 Flashcards
what are the two most common causes of megaloblastic anemias
B12 and folate deficiencies
CBC in megaloblastic anemia shows what
pancytopenia- decreased RBC counts, WBC counts and platelet counts
the bone marrow in megaloblastic anemia shows what
giant bands
nuclear-cytoplasmic asynchrony
the peripheral blood in megaloblastic anemia shows what
macrocytic anemia
macro-ovalocytes
anisopoikilocytosis
hypersegmented neutrophils
neurological defects are associated with what cause of megaloblastic anemia
B12 deficiency
signs and symptoms of B12 and folate deficiencies
anemia
atrophic glossitis
gastric gland atrophy
neurologic (B12 only)
neurologic effects of B12 are due to what
demyelination of white matter of brain and dorsolateral columns of spinal chord
methylmalonic acid does this
in anemias of chronic disease where are iron levels increased
bone marrow- mostly macrophages
pernicious anemia is due to what
absent intrinsic factor (IF) which binds vitamin B12
pernicious anemia is likely what kind of disease
autoimmune
the autoantibodies in pernicious anemia are divided up how
Type I- (blocking)- block binding of B12 to IF Type II (binding)- bind B12-IF complex
pernicious anemia is associated with what
autoimmune disease:
hashimotos thyroiditis
adrenalitis
Grave’s disease
the shilling test is used to measure what
absorption of B12
folate deficiency is usually due to what
dietary insufficiency
folate can be stored for how long and where
3-6 months in liver
stage 1 of shilling test is done how
give radio labeled oral B12 and inject unlabeled B12 in bone
collect urine after 24 hours
Normal if a lot of of radio labeled B12 excreted
if abnormal proceed to stage II
stage 2 of shilling test is done how
oral radiolabled B12 + IF
Inject IM unlabeled B12
if results are normal there is a IF deficiency (pernicious anemia)
if abnormal results small bowel malabsorption (celiac)
If shilling test results yields abnormal stage I but normal stage II what does this mean
the stomach cannot make intrinsic factor/IF as in pernicious anemia
If shilling test results yields abnormal stage I and stage II what does this mean
malabsorption of vitamin B12 and IF in the small intestine as in biliary disease, celiac disease, hypothyroidism, liver disease
macrocytic anemia causes other than folate and B12
chemo
alcoholism
hypothyroidism
liver disease
Diamond-Blackfan syndrome is the primary form of what
Pure Red Cell aplasia
what is seen the peripheral blood of aplastic anemia
no reticulocytosis
pancytopenia
normocytic, normochromic anemia
a dry tap is seen in what anemia
aplastic anemia
what is seen clinically in aplastic anemia
anemia
neutropenia (infections)
thrombocytopenia (bleeding)
how is aplastic anemia acquired
chemical, toxins, drugs, radiotherapy/irradiation, viral infections, SLE
what is the most common acquired cause of aplastic anemia
autoimmune suppression by a T-cell mediated cell mechanism
half of acquired aplastic anemias are due to what
idiopathic
heridary aplastic anemia is also known as what
Fanconi’s anemia
hereditary aplastic anemia is due to defects in what
DNA repair mechanism
what congenital anomalies are seen with Fanconi’s anemia
hypoplastic radii
thumbs
organs
Pure Red Cell Aplasia is what
only erythroid (RBC) cell line affected myeloid and platelet lines normal
Pure Red Cell Aplasia what is seen in bone marrow
few to absent erythroid (RBC) precursors (erythroblasts)
Pure Red Cell Aplasia is what type of disease and what mediates it
autoimmune disease mediated by T-lymphs or IgG antibody vs red cell precursors
what viruses can cause aplastic anemia
Hepatitis, EBV, HIV, parvovirus
pure red cell aplasia is associated with what
SLE
CLL
thymomas
chloramphicol
what is diamond-blackfan syndrome
severe anemia in first year of life, with congenital anomalies
secondary form of pure red cell aplasia is due to what most of the time
infections especially parvovirus B19
sideroblastic anemia is characterized by what histologically
ringed sideroblasts (cells with iron granules around the nucleus)
sideroblastic anemia is due to what
failure to incorporate heme into protoporphyrin to form hemoglobin
(adequate iron stores but defective utilization of red blood cells
in sideroblastic anemia what are serum iron, transferrin saturation, and ferritin levels
all high
hereditary sideroblastic anemia is transmitted via what pattern
X-linked recessive
hereditary sideroblastic anemia is due to what
ALA synthase defect (rate limiting step in heme synthesis)
how can sideroblastic anemia be acquired
myelodysplasia
drugs (alcohol, isoniazid)
LEAD
nutritional deficiency
how do you treat sideroblastic anemias
pyridoxine (vit b6)
