Hematology Flashcards
Diagnosis:
Neonate with
- Persistent jaundice
- Splenomegaly
- Hemolytic anemia
- Positive family history
- Spherocytes on peripheral blood smear
Hereditary Spherocytosis
Diagnosis:
Hereditary Spherocytosis
- Acidified glycerol lysis–> RBC fragility
2. Eosin-5-maleimide binding test
Which pregnant women are administered a dose of anti-D immune globulin at 28 weeks gestation?
Rh-D negative mothers with Rh-D positive fetuses
Standard dose= 300 ug at 28 weeks gestation
What is the Kleihauer-Betke (KB) test used for?
The Kelihauer-Betke test is used to determine if an increased dosage of anti-D immune globulin is needed in pregnant Rh-D negative women who have experienced: (1) placental abruption (2) delivery of a Rh-D positive fetus or (3) any other procedure (eg, amniocentesis, chorionic villus sampling, external cephalic version)
*KB test: Acid is added to a smear of maternal RBC cells. Maternal RBCs are lysed leaving fetal cells behind. Fetal cells are calculated to determine the dosage of anti-D immune globulin.
What is the most common complication seen in patients with sickle cell trait?
(1) Painless hematuria
Note, SCT carriers can also experience: (2) isothenuria-impaired concentrating ability presenting as nocturia and polyuria (3) UTIs-especially during pregnancy.
Treatment:
Patient with a PMHx significant for COPD is found to have a proximal DVT and an active GI bleed
Inferior vena cava (IVC) filter
Patients with a DVT who have contraindications to anticoagulation (recent surgery, acute hemorrhagic stroke, bleeding diathesis, or active bleed) or recurrent DVT after treatment with anticoagulation should be considered for an IVC filter.
What is Virchow’s triad?
- Stasis
- Endothelial injury
- Hyper-coagulability
This triad of findings can result in a deep venous thrombosis (DVT).
What is the most common cause of vitamin B12 deficiency in whites of northern European ancestry?
Pernicious Anemia
Diagnosis:
- Megaloblastic anemia
- Atrophic glossitis (shiny tongue)
- Vitiligo
- Thyroid disease
- Neurologic abnormalities
Pernicious Anemia
Treatment:
What is the acute management for a deep vein thrombosis? What is the long term management?
Acute Tx: Heparin
Long-term Tx: Warfarin for several months
Note, major surgery is a significant risk factor for DVT. Patients should be started on anticoagulation as early as 48-72 hours after surgery.
Diagnosis:
1-year-old boy with a history of multiple episodes of otitis media and 2 hospitalizations for pneumonia is found to have:
- dry, scaly patches on his cheeks and lower extremities
- bruising and purpura on his lower extremities
Wiskott-Aldrich syndrome is an X-linked disorder that presents with a classic triad of:
(1) Hx of bacterial infections
(2) eczema
(3) thrombocytopenia
Pathogenesis:
Thrombocytopenia in patients with Wiskott-Aldrich syndrome
Deceased platelet production
Note, on blood smear the few platelets produced by the patients will appear smaller than normal.
What is the next best step in the management of a 3-year-old African American boy with a PMHx of severe upper extremity pain and hand swelling presenting with signs of stroke (e.g., hand clumsiness, difficulty walking)?
peripheral blood smear and reticulocyte count
This patient has a history of dactylitis and presents with signs of stroke. This is highly suspicious of sickle cell anemia.
How long does it take a person with underlying liver disease to deplete their vitamin K stores?
7-10 days
A normal liver will store a 30 day supply of Vitamin K.
What effect does vitamin K deficiency have on PT and PTT?
Both will be prolonged
Vitamin K deficiency results decreased plasma levels of Factors 2, 7, 9, 10, Protein C and S. First PT will be prolonged then the PTT will follow.
Rh(D) incompatibility vs. ABO incompatibility
Which causes more severe hemolytic disease of the newborn?
Rh(D) incompatibility
Infants affected by ABO incompatibility are typically asymptomatic at birth, have mild anemia, or develop jaundice which can be treated with phototherapy.
Management:
What is a good initial diagnostic step when treating a patient with microcytic, hypochromic anemia
Iron studies
Iron deficiency: low Fe, low ferritin, low transferrin saturation, high TIBC, increased RBDW
Thalassemias: normal to high Fe and ferritin
Anemia of Chronic disease: low TIBC, normal to increased ferritin
Sideroblastic anemia: normal to high serum iron and ferritin
What complication might present after starting a patient on heparin therapy?
Heparin-induced thrombocytopenia (HIT)
Patients develop thrombocytopenia, BUT are highly thrombogenic and must be monitored very closely for arterial and venous clots.
Seven acquired risk factors for venous thromboembolism (VTE)
- Immobilization
- Surgery
- Trauma
- Malignancy
- Pregnancy
- Medication (OCPs)
- Connective tissue disease
How can you differentiate between folic acid and cobalamin deficiencies using: (1) homocysteine and (2) methylmalonic acid?
Both folic acid and vitamin B12 deficiency will lead to INCREASED homocysteine levels, but ONLY vitamin B12 deficiency will cause an INCREASE in methylmalonic acid.
Which viral diseases should all patients presenting with seemingly idiopathic thrombocytopenia purpura be tested for?
- Hepatitis C
2. HIV
Diagnosis:
- Hemolytic anemia
- Cytopenia
- Hypercoagulable state (intrabdominal or venous thrombosis)
Paroxysmal nocturnal hemoglobinuria
Diagnosis:
Paroxysmal nocturnal hemoglobinuria
Flow cytometry to confirm the absence of CD55 and CD59 proteins on the surface of the RBCs.
Diagnosis:
Patient develops an acute hemolysis after ingesting primaquine or a sulfa drug
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Diagnosis:
Negative G6PD activity in a patient who developed an acute hemolysis after ingesting primaquine or a sulfa drug
Most likely Glucose-6-phosphate dehydrogenase (G6PD)
Note, G6PD activity will appear normal during the hemolytic episode as all the G6PD-deficient RBCs have hemolyzed early and the normal reticulocytes are present in high number.
Differential diagnosis:
Top Ddx in a traffic controller who works in an underground parking lot who presents with:
- Headache
- Nausea
- Dizziness
Carbon monoxide poisoning
Note, CBC may show an increased hematocrit due to the bodies increased hematopoesis to compensate for the increase in carboxyhemoglobinemia, a molecule with decreased O2 carrying capacity.
Common ways competitive athletes enhance their athletic performance?
- Exogenous androgens
- Autologous blood transfusions
- Erythropoietin
Clinical manifestation:
Exogenous androgen administration in a competitive male athlete
- Mood disturbance
- Gynecomastia
- Testicular atrophy
- Hepatotoxicity
What happens if you treat a vitamin B12 deficient patient with only folic acid?
Their anemia will be corrected, but neurologic complications will rapidly progress.
Causes of folic acid deficiency:
- Poor nutrition (diet, alcoholism)
2. Drugs (phenytoin, methotrexate, trimethoprim)
Mechanism of Action:
How do phenytoin, methotrexate and trimethoprim cause folic acid deficiency.
Phenytoin: impairs the absorption of folic acid
Methotrexate and Trimethoprim: antagonize the physiologic effects of folic acid
Treatment:
Immune thrombocytopenic purpura (ITP)
Glucocorticoids for severe thrombocytopenia (platelets
Diagnosis:
Immune thrombocytopenic purpura
This is a diagnosis of exclusion. Patients typically present with:
(1) History of viral infection
(2) Asymptomatic petechiae
(3) Ecchymosis
(4) Mucocutaneous bleeding.
Which three (3) vitamins are involved in the metabolism of homocysteine?
- Vitamin B6 (pyridoxine)
- Folate
- Vitamin B12 (cobalamin)
Diagnosis:
Peripheral blood smear of a patient with glucose-6-phosphate dehydrogenase deficiency
Heinz bodies (red cell inclusions after crystal violet stain)
Three potential causes of hemolysis in a glucose-6-phosphate deficient patient:
- Oxidant drugs (antimalarials, sulfas)
- Infection
- Fava beans
What is the most important initial screening test in a non-African descent female seeking preconception counseling.
Complete blood count (CBC)
If the patient had African-descent, you would obtain a hemoglobin electrophoresis along with the initial CBC.
Diagnosis:
- Normocytic anemia
- Splenomegaly
- Reticulocytosis
- Jaundice
- Elevated indirect bilirubin
- Increased serum lactate dehydrogenase
- Decreased serum haptoglobin levels
warm Autoimmune Hemolytic Anemia (AIHA)
?
Treatment:
Autoimmune hemolytic anemia (AIHA)
- High-dose glucocorticoids
2. Splenectomy if patients have severe hemolysis, do not respond or are unable to tolerate glucocorticoids.
Patients with systemic lupus erythematosus (SLE) can have concurrent peripheral immune-mediated destruction of which cell lines?
RBCs, WBCs and platelets
These patients present with pancytopenia. Other hematologic manifestations of lupus include: anemia, leukopenia, thrombocytopenia and antiphospholipid syndrome.
What is the most common adverse reaction that occurs within 1-6 hours of transfusion?
Febrile nonhemolytic transfusion reaction
Clinical manifestation:
Febrile nonhemolytic transfusion reaction
- Fever
- Chills
- Malaise
- No signs of hemolysis
How can you prepare donor blood to decrease the risk of febrile nonhemolytic transfusion reaction?
Leukoreduction can prevent febrile nonhemolytic reaction, reduce the risk of HLA alloimunization and cytomegalovirus transmission.
Leukoreduction involves filtering, saline washing, freezing, deglycerolizing or removing the buffy coat from donor samples to reduce the number of transfused leukocytes.
Treatment:
Coagulopathy in a patient with liver failure
Fresh frozen plasma is the therapeutic agent of choice.
Pathogenesis:
Polycythemia in patients with obstructive sleep apnea (OSA)
Hypoxemia-induced increase in erythropoietin production leads to erythrocytosis
How might a patient experiencing an anaphylactic reaction to transfused blood products present?
Within seconds to minutes of the transfusion.
(1) Rapid onset of respiratory distress
(2) Hypotension
These symptoms may progress to respiratory failure and shock.
Treatment:
Acute management of anaphylactic reaction to transfused blood products
- Epinephrine
- Circulatory support (i.e. vasopressors)
- Respiratory support (i.e. mechanical ventilation)
Patients should also be given histamine blockers and glucocorticoids.
Both autoimmune hemolytic anemia (AIHA) and hereditary spherocytosis (HS) cause extravascular hemolysis and show sphereocytes without central pallor on peripheral blood smear. How are they different?
AIHA is suggested in a patient with a negative family history and a positive Coombs test.
HS is suggested in a patient with a positive family history and a negative Coombs test.
Diagnosis:
51 year old man with:
- Dizziness
- Headache
- Pruritus that is especially bad after showers
- Splenomegaly
Polycythemia vera
dizziness + headache= signs of hyperviscosity
Diagnosis:
Polycythemia vera
- JAK2 mutation (present in >95%)
2. Low erythropoietin levels
What is Trousseau’s syndrome?
Trousseau’s syndrome is a hypercoagulability disorder that presents with recurrent and migratory superficial thrombophlebitis at unusual sites (e.g. the arms and chest area).
In a patient with migratory superficial thrombophlebitis in unusual sites (eg, arms, chest), what associated diseases should you watch for?
Trousseau’s syndrome is usually associated with an occult visceral malignancy (pancreatic, stomach, lung, prostate).
Pancreatic malignancy is most common.
Treatment:
Chronic kidney disease induced anemia
- Erythropoietin
- Iron
Ensure adequate iron stores PRIOR to erythropoietin because the erythropoietin induced surge in RBC production can precipitate an iron deficient state.
Common complication associated with hereditary spherocytosis.
Acute cholecystitis from pigmented gallstones
Clinical manifestation of acute cholecystitis: fever, RUQ pain, + Murphy’s sign (RUQ tenderness exacerbated by inspiration), leukocytosis
What type of anemia are patients with artificial heart valves or severely calcified aortic valves at risk for?
Microcytic anemia caused by macrovascular hemolysis
Mechanism of Action:
Heparin-induced thrombocytopenia
- Heparin therapy exposes a neoantigen on the surface of platelets by causing a conformational change in platelet factor 4.
- HIT antibodies form against the neoantigen.
- HIT antibodies bind the surface of platelets causing thrombocytopenia, platelet aggregation and a prothrombotic state.
Diagnose:
Heparin-induced thrombocytopenia
- Functional assay –> serotonin release assay= gold standard
- Immunoassay (if high titers)
Do NOT wait for diagnostic test. Treat immediately if you suspect HIT! The risk for arterial or venous thrombosis is as high as 50% if left untreated.
What is the most common cause of superior vena cava syndrome?
Malignancy
- Small cell lung cancer
- Non-Hodgkin lymphoma
List all the potential causes of superior vena cava syndrome.
- Small cell lung cancer
- Non-Hodgkin lymphoma
- Fibrosing mediastinitus (2/2 Histoplasmosis or Tuberculosis)
- Thrombosis (2/2 indwelling central venous devices)
When does leukemoid reaction occur?
Leukemoid reaction occurs when a patient has a severe infection. Leukocyte count can be >50,000/mm3
How does leukemoid reaction differ from chronic myeloid leukemia?
Leukemoid reaction involves
- Higher alkaline phosphatase score
- More late precursor neutrophils (eg, metamyelocytes and bands)
- absolute basophilia
What is a common side effect of erythropoietin use in patients with chronic kidney disease?
Hypertension.
Note: Patients who receive a large dose, or experience a rapid rise in their hemoglobin are at the highest risk.
What is the most common cause of inadequate response to ESAs in chronic kidney disease patients on dialysis?
Iron deficiency
What diagnosis should you suspect in an alcoholic smoker presenting with a palpable cervical lymph node?
Squamous cell carcinoma of the mucosa of the head and neck
What is the initial test in a patient with suspected squamous cell carcinoma of the mucosa of the head and neck?
Panendoscopy
Treatment:
Polycythemia vera
- Serial phlebotomy
2. Bone marrow suppressive drugs (eg, methotrexate) if there is a high risk of thrombosis
Laboratory values showing:
- Decreased serum haptoglobin
- Elevated bilirubin
- Elevated lactate dehydrogenase
Hemolytic anemia
What might you seen on the peripheral blood smear of a patient with a mechanical heart valve?
Schistocytes (helmet cells)
These are fragmented erythrocytes.
Diagnosis:
- Hemolytic anemia
- Splenomegaly
- Jaundice
…in a person of Northern European descent
Hereditary Spherocytosis
What genetic inheritance pattern is associated with G6PD?
X-linked recessive
Both sideroblastic anemia and iron deficiency anemia present as microcytic/hypochromic anemias. How can you distinguish the two?
Sideroblastic anemia is associated with:
(1) High serum Fe
(2) Decreased TIBC
Iron deficiency anemia
(1) Low serum Fe
(2) Low ferritin
(3) Low transferrin saturation
(4) Increased RBDW
(5) Increased TIBC
Treatment:
Beta-thalassemia minor
None.
How can you distinguish iron deficiency anemia from beta-thalassemia minor?
beta-thalassemia minor is associated with:
- INCREASED RBC count
- Hemoglobin >10
- Low MCV
Iron-deficiency anemia:
- Low RBC count
- Low MCV
- Microcytosis does not occur until hemoglobin <10
