Flashcards in Ch. 5 - Normocytic with Extravascular Hemolysis Deck (99):
What lab value helps you determine if a normocytic anemia is from over destruction or underproduction?
WHat is a normal RETC
A properly functioning bone marrow responds to anemia by increasing the RETC to (blank)
T/F: RETC is falsely elevated in anemia
How is RETC falsely elevated in anemia?
percentage of total RBCs, so if the total count of RBCs decreases, then the RETC looks higher than it should be
How do you calculate the corrected RETC?
(Hct/45) x RETC
A corrected RETC >3% tells you what?
good marrow response and suggests PERIPHERAL DESTRUCTION
A corrected RETC
bad marrow response and suggests UNDERPRODUCTION
T/F: intravascular and extravascular hemolysis both present as an anemia with a good marrow response
What are the following components of RBCs broken down into?1. globin2. heme3. protoporphyrin
1. amino acids2. iron and protoporphyrin; iron is recycled3. unconjugated bilirubin, bound ot serum albumin and delivered to the liver for conjugation and excretion into the bile
Peripheral RBC destruction will result in (splenomegaly/HSM)
splenomegaly only, but jaundice!
What painful dietary complication are pts at risk of developing with increased levels of bilirubin?
T/F: peripheral blood cell destruction results in marrow hyperplasia
Is this intravascular or extravascular?HemoglobinemiaHemoglobinuriaHemosiderinuria
Why do pts with intravascular hemolysis present with hemosiderinuria? When does this develop?
renal tubular cells pick up some of the hemoglobin that is filtered into the urine and break it down into iron, which accumulates as hemosiderin; tubular cells are eventually shed resulting in hemosiderinura.
Is serum haptoglobin increased or decreased in intravascular hemolysis?
decreased; hapto is a scavenger molecule that will try to take up the free Hgb in the blood
What range of increased LDH would we see for extravascular hemolysis?
What is the first organ to sense hypoxia and what hormone becomes elevated in extra. hemolysis?
kidney; increased EPO
In a chronic extravascular hemolysis, what characteristics of the anemia are added that complicate the DDx?
increased folate requirements and iron deficiency which could make you think it was a folate def or simple iron def. anemia
What are the five things you think of when you see a macrocytic anemia?
Folate def.Vit. B12 def.AlcoholismMDSLiver disease
What are the two things that increase the RETC count>?
bleeding or hemolysis
If spherocytes are present on the peripheral smear, what are the only two things on your DDx?
1. autoimmune hemolytic anemia2. Hereditary spherocytosis
What other clues can we get from a CBC that lets us know that the cause of the anemia is from an underproduction in the bone marrow
you will likely see that other cell lines are low too
What is the molecular cause of Hereditary spherocytosis? (HS)
RBC cytoskeleton-membrane tethering proteins
What three proteins are most commonly affected in HS>?
ankyrin, spectrin, or band 3, protein 4.2
WHat causes RBCs to become spherocytes in HS?
formation and loss of membrane blebs
How does HS cause anemia?
spherocytes cannot pass through splenic sinusoids and are consumed by the splenic macrophages
Spheroctyes have a (loss/increase) in central pallor
What changes would happen to these labs in HS?RDWMCHC
increased RDWincreased MCHC
What complication of increased bilirubin presents in HS?
T/F: pts with HS are normally jaundiced but have normal liver function
Pts with HS are at an increased risk of (blank) post parvovirus B19 infection
How do you Dx HS?
osmotic fragility test; increased fragility
What is the Tx for HS?
What two cellular abnormalities persist on the peripheral smear after splenectomy in HS?
spheroctyes and howell-jolly bodies
Sickle cell anemia (SCA) is caused by a single amino acid mutation in the beta chain from (blank to blank)
glu to val
SCA is protective against which strain of malaria?
When does SCA become sickle cell disease?
mutation in both beta genes
what percent of Hgb is Hbs in sickle cell disease?
What happens to HbS when it is deoxygenated?
polymerizes into needle like structures and causes sickling
T/F: HbS molecules covalently bind to each other to form a tetramer upon deoxygenation
false; they POLYMERIZE
An increased risk of (blank) occurs with hypoxemia, dehydration, and acidosis when you have a fucked up beta gene
What type of Hb is protective against sickling?
Do we see SCA in newborns?
nope, HbF is protective for the first few months of life
Tx with (blank) increases levels of HbF and is used in SCA
T/F: In SCA, cells continuously sickle and de-sickle
What is the result of dynamic sickling in SCA?
extravascular hemolysis b/c of damaged membranes
T/F: SCA leads to elevated bilirubin and risk for bilirubin gallstones
T/F: SCA presents with both intra and extravascular hemolysis
What are the lab changes associated with intravascular hemolysis in SCA?
decreased serum haptoglobulin
What cell type is seen on peripheral smear as a result of intravascular hemolysis in SCA?
cErythroid hyperplasia due to SCA results in extramedullary hematopoiesis with what three characteristic findings?
crew cut skull xraychipmunk faciesHSM
T/F: pts with SCA are risk of aplastic crisis
true, post parvovirus B19 infx
Extensive sickling leads to complications of vaso-occlusion inluding (blank)
Dactylitis is the vaso-occlusive event of swelling of the hands and feet from infarcts in the (bone/soft tissue)
(blank) is a shrunken, fibrotic spleen in response to SCA
Autosplenectomy results in an increased risk to (encapsulated/naked) pathogens
Which encapsulated pathogens pose a significant risk to pts who have autosplenectomy?
S. pneumoniae and H. flu
Pts with autosplenectomy have an increased risk of osteomyelitis caused by what bug>?
What abnormality can be seen on peripheral smear in patients with autosplenectomy?
howell jolly bodies
(blank) is a complication of SCA that is a vaso-occlusion in pulmonary micro-circulation
acute chest syndrome
Acute chest pain presents with pain, SOB, and lung (blank)
What precipitates acute chest syndrome in pts with SCA
What is the most common cause of death of adult SCA pts?
acute chest syndrome
what is the most common cause of death of children with sCA?
H. flu infection
The increased transit time of sickled RBCs through pulmonary circulation leads to increased acidemia, hypoxia, and dehydration which all promote further (blank)
Renal papillary necrosis in SCA results in gross (blank and blank)
hematuria and proteinuria
Sickle cell trait produces what percent of HbS?
T/F: pts with sickle cell trait are normally anemic
false; RBCs with less than fifty percent HbS do not sickle in vivo unless in extreme circumstances
T/F: pts with sickle cell trait have a hard time concentrating urine
What screening test is used to test for HbS in both the trait and disease?
metabisulfite; will cause sickling
What percent HbS and HbF is present in sickle cell disease?
90% HbS, 8%HbF
What percent of HbS is present in sickle cell trait?
What is the amino acid substitution that results in HbC?
glu to LYSINE
What causes the anemia in HbC?
What is the characteristic finding on peripheral smear of HbC?
What is the most common protein to be altered in hereditary spherocytosis?
Hereditary elliptocytosis is due to a defect in what two proteins?
spectrin tetramers or 4.1
T/F: hereditary elliptocytosis presents with mild anemia and splenomegaly
What disease presents this way?Strokegallstonespriapismaseptic necrosis of femoral headaplastic crisis post ParvoB19 infx
sickle cell anemia
What vitamin should pts with sCA take?
folic acid supplementation
Pts with G6PD def. have a susceptibilty to infections because they have an impaired (MPO/NADPH) oxidase system
In what type of IHA is Raynaud's common?
IgG mediated cold agglutinin
What are the alloimmune causes of IHA?
Rh hemolytic disease of the newbornABO mismatchHemolytic transfusion rxn
Drug induced IHA is (direct/indirect) coomb's positive
IgG normally does (intra/extra)vascular hemolysis
IgG is extraIgM is intra
What gene is involved in PNH?
T/F: PNH will present with pancyotpenia
T/F: PNH will present with decreased haptoglobulin
RBCs are damaged by (blank) buildup in DIC
A long distance runner may suffer what type of hemolysis?
Snake venoms, malaria, babesia, burns, and clostridium perfringens cause what type of anemia?
non-immune hemolytic anemia
Describe the following lab values in regard to hemolytic disease of the newborn:DATTotal and indirect biliLDHHCT and Hgb
1. pos DAT2. increased total and indirect bili3. increased LDH4. INITIALLY HCT and Hgb WNL
At what level of BUN does uremia present with anemia?
when BUN is twice normal
What type of cells are seen on peripheral smear in uremia?
Burr cells (echinocytes) spiny projections
T/F: traumatic hemolysis can form burr cells
Describe the size and color of uremic anemia
norchromic normocytic with MILD anisocytosis
Anemia with neoplasia will be normocrhomic normocytic anemia unless...(three things)
1. blood loss2. hemorrhage3. myelophthistic process