RBC Flashcards
characteristics of RBC
biconcave with central pallor
7-8 micrometers in diameter
deformable for capillaries and splenic fenestrations
anemia
reduction in circulating Hb, total number of RBCs, or circulating RBC mass
acute and chronic anemia compensation from bone marrow
acute-3x increase in 7-10 days
chronic-6 to 8x increase
signs of anemia
due to tissue hypoxia easy fatigue dyspnea pallor syncope postural hypotension angina
cardiovascular compensation
heart murmurs
more forceful apical impulse, palpitations
tachycardia
CHF
blood volume
3L plasma and 2L blood cells
MCH
Hb/RBC count
MCHC
(Hb/Hct)x100
RDW
distribution of size (high=anisocytosis)
reticulocyte count
young RBC with residual rRNA
increases in patients with normal renal (epo) and bone marrow functions
microcytic
iron def
thalassemia
normocytic
acute blood loss
chronic disease
macrocytic
vitamin B12
folate def
iron def anemia
most common
babies-excessive milk intake
decrease MCV, MCH, MCHC, increased RDW
iron cycle
transferrin-delivered to duodenum
transferrin receptor
ferritin-storage in cells and circulation (acute phase reactant)
causes of def in iron
nutritional
malabsorptional-GI surgery, enteritis, celiac sprue
blood loss-menstural, occult GI bleeding, hookworm, aspirin, chronic hemolysis, traumatic hemolysis
states requiring increased iron intake
infancy
adolescence
pregnancy
lactation
clinical signs of IDA
pallor
koilonychia
esophageal webs
pagophagia, pica
iron studies for IDA
high TIBC
low serum Fe, low ferritin
anemia of chronic disease
second only to iron def anemia in incidence
most common anemia in hospitalized patients
RBC life span in chronic disease
increased phagocytosis
factors released by damaged tissues
physical damage during passage of red cells through tissues
bone marrow in chronic disease
suppression by TNF, IL1
defective reutilization of iron salvaged from old RBC-sequestered in phagocytes
anemia studies in chronic disease
low serum iron
low transferrin
high ferritin
diseases associated with anemia
chronic renal failure DM inflammation cancer liver disease alcoholism
megablastic anemias
CBC shows pancytopenia
vitamin B12 and folate def
hypersegmented neutrophils
BM-giant bands, nuclear-cytoplasmic asynchrony
symptoms of B12 and folate def
anemia
atrophic glossitis
gastric gland atrophy
neuro (B12 only)-demyelination of dosolateral columns
B12 def causes
pernicious anemia
GI surgery
vegans-dietary insufficiency
states requiring increased B12
pregnancy
disseminated cancer
hyperthyroid
pernicious anemia
absent intrinsic factor
type 1 blocks B12 binding to If
type 2 blocks complex
diagnose with Schilling test
causes of pernicious anemia
autoimmune-Hashimoto, adrenalitis, graves
chronic atrophic gastritis-lost parietal cells
folate def
dietary insufficiency depleted stores (liver) in 3-6 months
diagnosis megablastic anemia
autoantibodies in pernicious anemia
high methylmalonic acid in B12
high homocysteine for both
treatment of megablastic anemia
B12-IM injections (reverse neuro if less than 6 months)
folate-passively absorbed
folate partially corrects for B12 def but not neuro deficits
aplastic anemia
stem cell injury/suppression
pancytopenia with no reticulocytosis
dry tap-no abnormal cells
clinical signs of aplastic anemia
anemia
prone to infections-neutropenia
bleeding-thrombocytopenia
no splenomegaly
acquired aplastic anemia
benzene, alcohol, myelotoxic drugs, chloramphenicol, NSAIS
radiotherapy/irradiation
viral-Hep, EBV, HIV, parvo
SLE
hereditary aplastic anemia
Fanconi anemia autosomal recessive defects in DNA repair mechanism congenital anomalies can progress to AML or CML or MDS
treatment of aplastic anemia
transfusion and antibiotics
immunosuppression-ATG, cyclophosphamide
bone marrow transplantation
pure red cell aplasia
only erythroid cell line affected
severe anemia
no reticulocytes
bone marrow-few to absent erythroid precursors
causes of pure red cell aplasia
autoimmune mediated against T lymphs or IgG antibody
SLE, CLL, lymphomas, thymomas
chloramphenicol
secondary-parvo B19, solid tumors, rheumatic diseases, phenytoin, azathioprine, isoniazid
Diamond-Blackfan snydrome
severe anemia first year of life with congenital anomalies
results in pure red cell aplasia
treatment of pure red cell aplasia
stop offending drugs
thymoma resection
IVIG (parvo)
immunosuppression-ATG and cyclosporine
sideroblastic anemias
failure to incorporate heme into protoporphyrin to form hemoglobin
dimorphic red cells, hypochromia, ineffective erythropoiesis
iron indices for sideroblastic
high serum iron
high ferritin
high transferrin saturation
hereditary sideroblastic
X linked
ALA synthase defect (rate limiting enzyme in heme synthesis)
acquired sideroblastic anemias
myelodysplasia
drugs-alcohol, isoniazid, chloramphenicol
toxins-lead, zinc
nutrional-pyridoxine, copper
treatment of sideroblastic anemias
pyridoxine (B6)
treat underlying condition and remove exposure to toxins
hemolytic anemias lab findings
unconjugated bilirubin
decreased haptoglobin (take up free Hb)
increased LDH
reticulocytosis
extravascular hemolysis
outside bloodstream in reticuloendothelial system
defects in hemoglobins, RBC membrane, RBC enzyme
spherocytes in peripheral blood
intravascular hemolysis
hemoglobinuria, hemsiderinuria
decreased haptoglobin
extrinsic causes-immune, microangiopathic anemias, infection, burns, hypersplenism
HbA
A2B2
HbA2
A2D2
HbF
A2G2
thalassemia
reduced production of one or more globin chains
beta thalassemia
decreased production of HbA
point mutations and partial deletions on chromosome 11
beta0
no beta globin at all (abnormal messenger RNA degraded)
beta+
reduced beta-globin gene
beta thalassemia major
onset 6-9 months after switch from HbF to HbA
anemia
compensation-abnormal bone growth, hepatosplenomegaly, damage to organs
treatment of beta thalassemia major
transfusion dependent for life
see increase in A2 and F on electrophoresis
beta thalassemia minor
one normal and one abnormal
iron makes beta thal worse (but PB looks like IDA)
alpha thalassemia
complete deletion of genes
severity depends on number of genes lost
PB shows basophilic stippling, target cells
loss of all 4 alpha
death in utero from hemoglobin bart
loss of 3 alpha
HbH are bitten off by splenic macrophages
Heinz bodies
loss of 2 alpha genes
alpha thalassemia trait
cis alpha thal 1
Hb bart
HbH inclusions during life
trans alpha thal 2
Hb bart
no HbH in life
sickle cell reversible to irreversible
initially reversible
later irreversible with repeated sickling (spectrin dimers instead of tetramers)
HbS
valine replaces glutamic acid in 6 of beta globin
sickle cell anemia presentation
expanded bone marrow extramedullary hematopoiesis autosplenectormy-salmonella osteomyelitis chronic leg ulcers vaso-occlusive crises dactylitis-swollen fingers avascular necrosis of femoral head
acute chest syndrome
dangerous microvascular occlusive crisis
CVA, fever cough and pulmonary infiltrates
infection from encapsulated-Strep and H. flu
prophylactic ABX
aplastic crises-parvo bone marrow suppression
splenic sequestration-splenomegaly and hypovolemia
priapism
organ infarction
gallstone formation from chronic extravascular hemolysis
peripheral blood sickle cell
crescent shaped sickles, basophilic stippling, Howell-Jolly bodies
diagnosis of sickle
sickling test with metabisulfate
HbA
weak interaction, need severe hypoxia to sickle
HbF
inhibits polymerization, can moderate severity
HbC
lysine substituted for glutamic acid in position 6 of beta globin chain
clinically less severe than SS
forms crystals in PB
tendency to sickle
dehydration
thalassemia
low pH
increased temperature
sickle cell therapy
hydroxyurea to increase HbF transfusions pain management folate ABX
hereditary spherocytosis
AD
RBC lose membrane as they pass thru spleen
mutation in ankyrin-anchor for lipid bilayer
leads to def of spectrin
hereditary spherocytosis presentation
hemolytic anemia jaundice, splenomegaly gallstones anemic crisis fever and infection induced crises
diagnosis hereditary spherocytosis
osmotic fragility test
microcytosis with increased MCHC
negative DAT
osmotic fragility test
put in sodium chloride and see if they lyse
treatment of hereditary spherocytosis
folic acid supplements
splenectomy
G6PD deficiency
may protect from falciparum malaria
episodic hemolysis with oxidant stress
not enough NADPH to maintain GSH
presentation of G6PD def
intravascular hemolysis due to Heinz bodies
fever, chills, hemoglobinemia, hemoglobinuria
G6PD infections
viral hep, typhoid, pneumonia
G6PD drugs
oxidant drugs
antimalarials, sulfonamides, nitrofurantoin, chloramphenicol
G6PD foods
fava beans
immune hemolytic anemias
autoimmune hemolytic anemias
alloimmune hemoltyic anemias
DAT
antiglobulin used to detect RBC coated with antibodies
used to diagnose autoantibodies in autoimmune hemolytic anemias
WAHA
IgG autoantibodies
extravascular hemolysis
drug induced-L-dopa, penicillin, tetracyclines, cephalosporins, tolbutamide
disorders with WAHA
lymphatic malignancies
SLE, RA, UC
treatment of WAHA
corticosteroids
blood transfusions, gammaglobulins, plasmapheresis
splenectomy
CAIHA
monoclonal IgM at low temperatures I-A,B,O i fix complement C3 extravascular hemolysis without splenomegaly
acute CAIHA and chronic CAIHA
acute-mycoplasma pneumo (I) and mono (i)
chronic-lymphoid malignancy
paroxysmal cold hemoglobinuria
IgG autoantibody in biphasic hemolysis
causes of paroxysmal cold hemoglobinuria
mycoplasma pneumo
mono
syphilis
no jaundice or splenomegaly
Donath-Landsteiner
differentiate PCH from CAIHA
hemolytic transfusion reaction
ABO incompatible blood
intravascular hemolysis via complement fixation
hemolytic disease of newborn
hemolysis of newborn RBCs
transplacental transmission of maternal antibodies against Rh positive fetal RBCs
sources of maternal immunization in hemolytic disease of newborn
previous blood transfusion
previous pregnancy, delivery (due to fetal-maternal hemorrhage)
nonimmune hemolytic anemias
microagniopathic HA
infections
acquired-alcoholic liver disease, paroxysmal nocturnal hemoglobinuria
mechanical and physical factors
microangiopathic HA
abnormalities in microcirculation-fibrin deposition DIC HUS TTP preeclampsia
alcoholic liver disease peripheral blood
acanthocytes or spur cells
paroxysmal nocturnal hemoglobinuria
mutation in phosphatidyl inositol glycan class A (PIGA) synthesis of GPI in cell membrane defects in CD59/55
CD55
DAF
CD59
MIRL
tests for paroxysmal nocturnal hemoglobinuria
sucrose lysis test
Ham’s test
flow cytometry
progression of paroxysmal nocturnal hemoglobinuria
aplastic anemia
myelodysplasia
AML
treatment of paroxysmal nocturnal hemoglobinuria
iron supplements
prednisone
bone marrow transplant
prosthetic heart valves
artificial more than porcine valves
mild anemia to hemolytic anemia
march hemoglobinuria
marching, marathon running
hemoglobinuria after exercise
normal PB smear, anemia is rare
burn injury PB
microspherocytes, barbell shapes, rod shapes
