Hematology Flashcards
describe the image
hereditary spherocytosis
note the anisocytosis and several hyperchromic spherocytes
Howell-Jolly bodies (small nuclear remnants) are also present in the red cells of this asplenic patient (seen on the right)
describe the type of anemia that is seen in the image
normocytic anemia with predominant extravascular hemolysis
describe the etiology of the condition seen in the image
- etiology = intrinsic/genetic defect in RBC membrane proteins
- ankyrin (AD)
- spectrin (AR)
- band 3.1
describe the pathogenesis of the condition seen in the image
- pathogenesis:
- reduced RBC membrane stability → loss of small fragments during normal shearing stresses in the blood circulation → spherocytosis to accommodate → unable to traverse the splenic sinusoids → phagocytosis and destruction by splenic macrophages → splenomegaly usually seen due to functional hypertrophy
describe the change in SA:V ratio in the condition seen in the image and what it affects
- decreased SA:V ratio (spheres) → pack more Hb → no central pallor → increased MCHC (due to cell becoming more concentrated) & increase in RDW
in the condition seen in the image, ___ can deliver O2 normally but ___ recognizes them as foreign
in the condition seen in the image, spherocytes can deliver O2 normally but the spleen recognizes them as foreign → chronic extravascular hemolysis
describe the presentation of the condition seen in the image
- mild to chronic hemolytic anemia, jaundice, fatigue, dragging sensation in LUQ due to splenomegaly
describe the lab findings in the condition seen in the image
- ↑ reticulocytes (reticulocytosis)
- ↑ LDH
- ↑ MCHC (only condition that has this)
- ↑ RDW
- ↑ unconjugated bilirubin
- ↓ MCH
describe the osmotic fragility test in relation to the condition seen in the image
- osmotic fragility test:
- in 65% of patients with HS, RBCs lyse prematurely compared to normal when exposed to increasingly hypotonic solution
describe the complications of the condition seen in the image
- all anemias → LVH → LHF → RHF → CHF
- rapid production of RBCs uses folate → folate def. anemia → megaloblastic anemia
- increased risk of aplastic crisis due to Parvovirus B19 (infects normoblasts/erythroid precursors) → reticulocytopenia in chronic hemolytic anemia
- bilirubin gallstones → cholecystitis due to supersaturation of bilirubin in bile → increased chance of precipitation
in the condition seen in the image, there is an increased risk of aplastic crisis due to ____
in the condition seen in the image, there is an increased risk of aplastic crisis due to Parvovirus B19 which infects normoblasts/erythroid precursors
describe the treatment for the condition seen in the image
splenectomy & folic acid supplements
will see HJ bodies upon splenectomy
describe the image
G6PD
as the splenic macrophages pluck out the Heinz bodies inclusions, “bite cells” are produced
describe the image
G6PD
red cells with precipitates of denatured globin (Heinz bodies) shown by supravital staining
describe the type of anemia seen in the condition in the image
normocytic anemia with predominant intravascular hemolysis (due to abnormality in HMP shunt)
describe the etiology of the condition seen in the image and name the 2 types of mutations
- etiology = X-linked recessive
- 2 types of mutations (role against falciparum malaria)
- G6PD A (African variant) = mild version → only older RBCs are affected
- G6PD (Mediterranean variant) = more severe → even younger RBCs are affected
describe the pathogenesis of the condition seen in the image
- pathogenesis: abnormal enzymes are misfolded
- ↓ G6PDH → ↓ NADPH → ↓ GSH → oxidative injury by H2O2 → intravascular hemolysis
- oxidative stressors = fava beans, infections/antibiotics, antimalarial & sulfa drugs
- mechanism: oxidation of SH groups on globin chains of Hb → Hb precipitates as Heinz bodies → damage to RBC membrane → intravascular hemolysis (predominantly)
describe lab findings seen in the condition in the image
- blood
- ↑ LDH
- ↑ unconjugated bilirubin
- ↑ free Hb
- ↑ reticulocytes
- ↓ haptoglobin (made by liver to bind free Hb)
- urine
- free hemoglobin → hemoglobinuria & hemosiderin → hemosiderinuria → dark urine
___ is the most accurate test for the condition seen in the image, but the downside is ____
G6PD assay is the most accurate test for the condition seen in the image, but the downside is may have to wait 2 months b/c reticulocytes produced at time of crisis do NOT reflect the enzyme deficiency – only mature RBcs do
list the most common outcome and complications of the condition seen in the image
self-limiting: complete resolution
- usually self-limiting with complete resolution after hemolytic event
- Hb (as is hemosiderin) is toxic to renal tubules → acute tubular necrosis → acute renal failure
describe the presentation of the condition seen in the image
- asymptomatic until exposed to injurious agent
- 2-3 days after oxidant stressor: acute hemolysis, fever, jaundice, fatigue, dark urine (due to free Hb)
- NO splenomegaly (differential from HS due to being intrinsic)
in the condition seen in the image, the most common predisposing factor for episodes is ____
in the condition seen in the image, the most common predisposing factor for episodes are infections
NADPH is needed for resp. burst
describe the type of anemia seen in the image
normocytic anemia with predominant extravascular hemolysis
describe the etiology of the condition seen in the image
- AR point mutation at position 6 of B-globin
- glutamic acid (polar) replaced by valine (neutral/non-polar) → removes biconcavity
- homozygotes (HbS, HbS) = sickle cell anemia
describe the cause of sickling and types of crises in the condition seen in the image
- crisis (increased sickling) caused by: hypoxia, acidosis, infection, dehydration, hypothermia, HbC (glutamic acid is replaced by lysine)
- types of crises: painful vaso-occlusive, hemolytic, splenic sequestration & aplastic crisis
describe the pathogenesis of the condition seen in the image
- pathogenesis: HbS polymerizes when deoxygenated → polymers aggregate into needle-like structures → sickle cells
describe the complications of the condition seen in the image
- prone to small vessel thrombosis → infarct
- sickled cells are “sticky” due to increased expression of adhesion molecules on their surface
- pooling of blood in the spleen aka sequestration crisis → rapid splenic enlargement and entrapment of sickled RBCs → hypovolemia → reticulocytosis present in peripheral blood → infarct → splenic fibrosis → autosplenectomy → HJ bodies
describe what is seen in blood serum levels in the condition seen in the image
- blood:
- ↑ reticulocytes
- ↑ LDH
- ↑ unconjugated bilirubin
- ↑ free Hb (dark urine)
- ↓ haptoglobin
the best screening test for the condition seen in the image is ____
the best screening test for the condition seen in the image is metabisulfite screen which causes cells with HbS to sickle
the test used for definitive diagnosis of the condition seen in the image is ____
the test used for definitive diagnosis of the condition seen in the image is hemoglobin electrophoresis (most accurate)
describe the treatment for the condition seen in the image
- bone marrow transplant
- hydroxyurea (stimulates HbF, increased NO, decreased platelet aggregation)
- vaccines after splenectomy
- folic acid
describe the presentation of the condition seen in the image in children
- children:
- crew-cut appearance & chipmunk face (due to hematopoiesis in skull)
- failure to thrive
- dactylitis (swollen hands and feet due to vaso-occlusive infarcts in bones → aseptic necrosis of metacarpal bones)
- spleen (crisis → splenomegaly → autosplenectomy due to fibrosis → recurrent encapsulated bacterial infxn = most common cause of death in children)
describe the presentation of the condition seen in the image in adults
sickle cell anemia
___ is the most common cause of death in adults with the condition seen in the image
acute chest syndrome: necrotizing pneumonia due to vaso-occlusion of pulm. arteries is the most common cause of death in adults
describe the type of anemia seen in the condition in the image
hypochromic microcytic anemia with extravascular hemolysis
describe 1 α-gene deletion
gene deletions on chr. 16
- 1 gene deleted = asymptomatic
describe the effect of 2 α genes deleted
- 2 genes deleted = miild anemia w/ increased RBC count
- cis deletion = increased risk of severe thalassemia in offspring
describe the effect of 3 α genes deleted
- 3 genes deleted = severe anemia
- B chains form tetramers (HbH) → high affinity for O2 → severe tissue hypoxia
- HbH is prone to oxidation → precipitated inclusions in older RBCs → extravascular hemolysis
- B chains form tetramers (HbH) → high affinity for O2 → severe tissue hypoxia
describe the effect of 4 α genes deleted
-
4 genes deleted = lethal in utero (hydrops fetalis)
- γ chains form tetramers (Hb Barts) → extremely high affinity for O2 → no O2 reaches the tissues
describe the etiology of the major form of the condition seen in the image
- point mutations of chr. 11
- absent B chain (B° caused by mutation in splicing/chain termination)
- diminished B chains (B+ caused by mutation in the promoter region)
describe genetic composition in B-thalassemia minor vs. B thalassemia major
- B-thalassemia minor = (B/B+) = mild asymptomatic anemia
- B-thalassemia major = (B°/B°), (B+/B+), (B+, B°) = severe transfusion-dependenent anemia; abnormal Hb causes occlusions in small blood vessels
describe the pathogenesis and presentation of the major form of the condition seen in the image
- no B chains (no HbA which is α2B2), which leads to an increase in HbF (α2γ2) and HbA2 (α2δ2)
- expansion of hematopoietic marrow in skull → chipmunk face, frontal bossing & crew-cut appearance due to erythroid hyperplasia in flat bones
- intramedullary hemolysis → ineffective erythropoeisis b/c α chains are not paired with B chains → α chains precipitate and form tetramers
- extravascular hemolysis: splenomegaly, fatigue, jaundice, brown discoloration of skin due to iron overload
describe the blood investigations found in the major form of the condition seen in the image
- blood:
- ↑ LDH
- ↑ reticulocytes
- ↑ RDW
- ↑ serum iron & ferritin
- ↓ TIBC
describe the diagnosis of the major form of the condition seen in the image
- diagnostic: Hb electrophoresis → no A band b/c no B chain, prominent F and normal/slightly elevated A2
describe what is seen on peripheral blood smear of the major form of the condition seen in the image
- PB:
- target cells, normoblasts, reticulocytes, anisocytosis, poikilocytosis due to extramedullary hepatopoeisis
the most common cause of death in the major form of the condition seen in the image is ____
the most common cause of death in the major form of the condition seen in the image is heart failure due to 2° hemochromatosis (due to increased blood transfusions)
describe the complications of the condition seen in the image
- aplastic crisis → due to Parvovirus B19
- folic acid deficiency due to chronic hemolytic anemia
- bacterial infections from iron-loving bacteria (Vibrio & Yersinia enterocolytica)
- bilirubin gallstones
- failure to thrive
describe the type of anemia seen in the image and why it is significant
microcytic hypochromic anemia
most common cause of anemia
list the 4 causes of iron deficiency
which is the most common in the Western world?
- dietary deficiency
- impaired absorption
- increased requirements
- chronic blood loss
- commonest cause of iron def. in the Western world
- where iron def. anemia is due to chronic GI blood loss until proven otherwise
- commonest cause of iron def. in the Western world
describe a diet that is at greater risk of acquiring the condition seen in the image
-
nutritional: iron from plants (non-heme) & animal (heme = better absorbed)
- vegan more likely to get IDA than B12 def.
most iron is absorbed in the ____
a small fraction enters the blood, but most remains in ___ and is lost by ____
most iron is absorbed in the duodenum
a small fraction enters the blood, but most remains in intestinal cells and is lost by intestinal exfoliation
___ a peptide synthesized in the ___ in response to high levels of iron stores, inhibits iron uptake from ___ mucosal cells into the bloodstream
hepcidin a peptide synthesized in the liver in response to high levels of iron stores, inhibits iron uptake from duodenal mucosal cells into the bloodstream
describe diseases that cause malabsorption that can lead to the condition seen in the image
-
malabsorption: absorption in duodenum affected by Crohns, tropical sprue, celiac disease and Whipple
- iron balance regulated at the level of absorption by hepcidin (inhibits iron uptake from duodenal mucosal cells into the bloodstream)
describe conditions of chronic blood loss that can lead to the condition seen in the image
- chronic blood loss:
- right-sided colon cancer → occult bleeding
- peptic ulcer by H. pylori → melena
- uterine fibroids → heavy bleeding (menorrhagia)
describe blood level values seen in anemia of chronic disease
- decreased serum iron
- decreased TIBC
- increased serum ferritin
- normal or increased iron stores in BM
- EPO levels inappropriately low
describe the pathogenesis of the condition seen in the image
- ↓ iron → ↓ heme → ↓ Hb → increased cell division → microcytic hypochromic anemia
list the stages of the condition seen in the image
- stages:
- storage iron depleted: ↓ ferritin; increased TIBC
- serum iron depleted: ↓ serum iron; ↓ % transferrin sat.
- normocytic anemia: bone marrow makes FEWER, NORMAL RBCs
- microcytic, hypochromic anemia: bone marrow makes smaller and fewer RBCs
describe the presentation of the condition seen in the image
- presentation:
- asymptomatic
- weakness
- pallor
- koilonychia (spooning of fingernails), ↓ reticulocytes due to no iron, ↓ MCV, ↓ MHC, ↓ MCHC, ↑ RDW
describe how Plummer Vinson syndrome can lead to the condition seen in the image
- PVS triad:
- IDA
- esophageal webs
- atrophic glossitis
describe the blood values in the condition seen in the image
- blood:
- ↓ iron & ferritin
- ↑ TIBC
- ↑ platelets
- ↑ free erythrocyte protoporphyrin
describe what is seen on PB smear of the condition seen in the image
- PB: anisopoikilocytosis (pencil cells), hypochromic microcytic cells and ↑ platelets
describe the most accurate test for diagnosing the condition seen in the image
- most accurate test = BM biopsy w/ Prussian blue (depletion of BM iron stores) → mild erythroid hyperplasia
describe the complications of the condition seen in the image
- complications:
- CHF
- if they have Plummer Vinson → sq. cell carcinoma of esophagus
- Pica syndrome (psychiatric problem w/ eating dirt, ice)
describe causes of anemia in chronic diseases (3 main groups)
- chronic bacterial infections
- lung abscess, endocarditis
- chronic immune disorders
- RA
- malignant tumors
- cancers of lung & breast, lymphoma
describe the impaired iron utilization and decreased RBC production seen in anemia of chronic disease
- decreased transfer of iron from the BM storage pool (macrophages) to RBC precursors, which is caused by hepcidin
- increased hepcidin production in chronic inflammatory states
- decreased erythropoiesis with inappropriately low erythropoietin
describe the lab values seen in ACD and IDA
describe how nutrition can lead to folate deficiency
lack of raw greens (boiling destroys folate)
most common cause of folate deficiency in older patients
name conditions where there is an increased demand for folate
increased demand during pregnancy, cancer, and chronic hemolytic anemia
name causes of malabsorption that can lead to folate deficiency
- malabsorption in the jejunum that can be caused by:
- Crohns
- Tropical sprue
- Celiac disease
- Whipples
name drugs that can lead to folate deficiency
phenytoin, methotrexate (chemotherapy)
describe blood level values seen in folate deficiency
which value is truly diagnostic of folate def.?
- increased homocysteine
- increased in both, folate and B12 def.
-
decreased serum folate
- only truly diagnostic test, as other changes could mean B12 def. too
describe what is seen on PB smear in folate deficiency
- hypersegmented neutrophils (>5 lobes)
- increased MCV
- decreased reticulocytes
- normal ferritin, TIBC
describe how pernicious anemia can lead to B12 deficiency
- pernicious anemia = antibodies destroying intrinsic factor = type II HS
- most common cause in the US
- pernicious anemia → intestinal gastric adenocarcinoma & type I gastric carcinoid
describe nutritional deficiencies that can lead to B12 deficiency
- nutritional: B12 found in dairy products & meat, therefore vegans can develop B12 deficiency
describe how malabsorption can lead to B12 deficiency
- malabsorption in ileum
- absorption in distal ileum affected by:
- Crohns
- Tropical sprue
- Celiac
- Whipples
- absorption in distal ileum affected by:
chronic ___ can lead to B12 deficiency
explain this concept
chronic pancreatitis can lead to B12 deficiency
- pancreatic enzymes are needed to cleave R binder from B12 so intrinsic factor can bind to it
describe the presentation of B12 deficiency
- presentation:
- fatigue
- atrophic glossitis
- cheliosis
-
neurological symptoms
- decreased vibration & proprioception due to subacute combined degeneration of dorsal column due to methylmalonic acid
list the blood levels values seen in B12 deficiency
- increased homocysteine
- increased methylmalonic acid
- low B12 (with normal folate)
describe how the Schilling test can be used to determine B12 malabsorption
- Schilling test = inability to absorb an oral dose of B12, measured by urinary excretion of labeled B12
the ____ response can be used to determine B12 deficiency
explain this
the reticulocyte response can be used to determine B12 deficiency
there would be improvement approx. 5 days after a parenteral B12 injection
PNH is caused by a mutation in ____
PNH is caused by a mutation in PIGA (X-linked)
describe the pathogenesis of PNH
- PIGA forms an enzyme needed to synthesize GPI
- 3 GPI-linked proteins normally inhibit complement activation on blood cells; absence of CD55, CD59 and C8-binding protein causes susceptibility to hemolysis
in PNH there is absence of CD__, CD___ and ____ which causes susceptibility to ____
in PNH there is absence of CD55, CD59 and C8-binding protein which causes susceptibility to hemolysis
list clinical features of PNH
- clinical features:
- intravascular hemolysis: chronic low-grade hemolysis
- thrombosis: platelet dysfunction → prothrombotic state
describe laboratory findings in PNH
- hemoglobinuria, hemosiderinuria
- older lab tests:
- sucrose hemolysis test (screening)
- Ham’s acid hemolysis test
- flow cytometry:
- absence of CD55, CD59 on WBCs
- Flaer test
if the flow cytometry image shown is normal, what is seen in PNH?
____ is the leading cause of death in PNH (40% develop ____)
thrombosis is the leading cause of death in PNH (40% develop DVT)
why is thrombosis seen in PNH?
platelets are also missing GPI (and therefore CD55, CD59) and are susceptible to complement-mediated killing
the destroyed platelets release cytoplasmic contents into circulation, causing thrombosis
there is a common association between PNH and ____
and ___ can also be a problem
there is a common association between PNH and aplastic anemia
and iron deficiency can also be a problem
a small number of PNH patients develop ____ or _____
a small number of PNH patients develop acute myeloid leukemia or myelodysplastic syndrome
list 2 possible treatments of PNH
- immunosuppression
- bone marrow transplantation
___ is the most common form of immunohemolytic anemia, with most antibodies being ____ class
warm antibody IHA is the most common form of immunohemolytic anemia, with most antibodies being IgG class
50% of patients with warm antibody IHA have predisposing factors, such as ___, ___ or ____
50% of patients with warm antibody IHA have predisposing factors, such as autoimmune diseases, lymphoma or drug reactions
cold antibody hemolytic anemia is mainly caused by ___ antibodies at ___ temperatures
cold antibody hemolytic anemia is mainly caused by IgM antibodies at cold temperatures
IgM = pentamer, so able to interact more and don’t need heating up to cause agglutination
list causes of microangiopathic hemolytic anemia (5)
DIC, malignant HTN, SLE, TTP/HUS, disseminated cancer
cardiac ____ can cause hemolysis due to mechanical RBC damage
cardiac prosthetic valves can cause hemolysis due to mechanical RBC damage
describe what is seen and what it is caused by
schistocytes are seen which can be caused by microangiopathic hemolysis
describe the etiology of idiopathic form of the condition seen in the image
- idiopathic = 65% of cases
- immune-mediated (cellular or T cell) destruction of antigenically altered stem cells
- primary intrinsic stem cell defect
- genetic abnormalities detected in some cases
describe the acquired causes of the condition seen in the image (3)
- chemical agents:
- dose-related, predictable
- alkylating agents and antimetabolites (chemotherapeutic agents)
- idiosyncratic
- chloramphenicol, chlorpromazine, phenytoin
- dose-related, predictable
- physical agents:
- whole body irradiation
- viral agents:
- hepatitis D and E, CMV, EBV, herpes zoster
describe the peripheral blood smear in the condition seen in the image
- PB:
- pancytopenia
- normochromic normocytic anemia
- very low reticulocyte count
in the condition seen in the image, ___ is necessary to rule out other causes of pancytopenia
- BM biopsy is necessary to rule out other causes of pancytopenia (acute leukemia, myelodysplastic syndrome)
- BM biopsy
- very hypocellular
- only fat cells, few lymphocytes, plasma cells
- very hypocellular
spontaneous remission of the condition seen in the image is uncommon in adults, but in children a ____ is more likely with a full recovery
spontaneous remission of the condition seen in the image is uncommon in adults, but in children a viral etiology is more likely with a full recovery
for the condition seen in the image,
younger patients can be treated with ____
while
older patients can be treated with ____
younger patients can be treated with bone marrow transplant
while
older patients can be treated with immunosuppression
in myelophthisic anemia, there is BM replacement by ____ that disturb ___ (often with ____)
in myelophthisic anemia, there is BM replacement by abnormal infiltrates that disturb normal architecture (often with fibrosis)
myelophthisic anemia can be caused by ____ & ____ and there is a ____ blood picture
myelophthisic anemia can be caused by metastatic cancer & granulomatous inflammation and there is a leukoerythroblastic blood picture
in diffuse liver disease, there is ___ hypofunction, affecting mainly ____, and the etiology is multifactorial
in diffuse liver disease, there is BM hypofunction, affecting mainly RBCs, and the etiology is multifactorial
in chronic renal failure, there is decreased production of _____
in chronic renal failure, there is decreased production of erythropoietin
list the 2 acquired platelet function abnormalities
- drugs:
- aspirin and NSAIDs
- uremia
- chronic renal failure
list the 4 categories of thrombocytopenia
- decreased platelet production
- decreased platelet survival
- sequestration (splenic)
- dilutional
list causes of decreased production of thrombocytes (thrombocytopenia(
- generalized BM disease
- aplastic anemia
- marrow infiltration
- leukemia, metastatic cancer, granulomatous inflam.
- drug-induced
- ethanol, cytotoxic drugs
- infections
- HIV, measles
- megaloblastic anemia
- myelodysplastic syndromes (MDS)
describe acute primary immune thrombocytopenia (ITP)
- acute:
- children
- post-viral
- abrupt onset
- spontaneous resolution
describe chronic primary immune thrombocytopenia (ITP)
- chronic:
- women 20-40
- insidious onset of skin +/- mucosal bleeding
- rarely resolves spontaneously
list the laboratory findings in chronic ITP
- decreased platelets
- increased bleeding time
- autoantibodies against platelet membrane glycoproteins
a PB smear in chronic ITP may show large ____ which indicates ____
a PB smear in chronic ITP may show large platelets which indicates rapid BM turnover
a BM biopsy in chronic ITP would show increased ____
a BM biopsy in chronic ITP would show increased megakaryocytes
list 2 potential treatments for chronic ITP
- immunosuppression via steroids
- splenectomy
list the 5 features found in thrombotic thrombocytopenic purpura (TTP)
- clinical syndrome of:
- fever
- thrombocytopenia
- microangiopathic hemolytic anemia
- transient neurologic deficits
- renal failure
how is HUS different from TTP?
clinically, HUS is like TTP, except HUS has NO neurologic deficits and instead has prominent acute renal failure
describe type I and type III vs. type II of von Willebrand disease
I and III = reduced quantity of vWF
II = qualitative (functional) abnormality of vWF
describe type I and II von Willebrand disease
- type I = 70% of all cases of vWD, with mild, mostly mucosal bleeding
- type II = 25% of vWD with mild to moderate bleeding
describe type III von Willebrand disease
- type III = severe deficiency/lack of vWF
- affects Factor VIII stability int he plasma so the patient may clinically present like Hemophilia A (increased PTT)
describe the lab findings in hemophilia A
factor VIII deficiency
- normal platelets, BT, PT
- prolonged PTT
list a treatment for hemophilia A and a potential complication
- recombinant FVIII infusions
- 15% develop FVIII antibodies
- also risk of transmission of viral diseases