Hematology Flashcards
List some extrinsic survival defects that cause anemia.
Examples of extrinsic (acquired) red cell survival defects include autoimmune hemolytic anemia, malaria, DIC, TTP, HUS, HELLP.
Is reticulocytosis increased or decreased for each of these: Production defect? Maturation defect? Survival defect?
Reticulocytosis is decreased in production and maturation defects and increased in survival defects.
When are Howell-Jolly bodies seen?
Howell Jolly bodies are seen in anatomically and functionally asplenic patients.
Characterize the lab values in iron deficiency anemia vs. anemia of chronic disease.
IDA causes a microcytic, hypochromic anemia. The iron level is low in both IDA and anemia of chronic disease. However, in IDA the TIBC is high (low in ACD), transferrin saturation is low (low to normal in ACD), ferritin is low (high to high-normal in ACD), and soluble transferrin receptor is high (normal in ACD).
What are the common causes of iron deficiency anemia?
The common causes of IDA are chronic blood loss, pregnancy, lack of dietary iron, malabsorption, and chronic low-grade intravascular hemolysis.
Characterize the CBC in patients with alpha-thalassemia minor.
Patients with alpha-thalassemia minor are typically asymptomatic with significant microcytosis with little to no anemia.
What is the characteristic hemoglobin electrophoresis finding in patients with beta-thalassemia minor?
In beta-thalassemia there is an increased A2 component on hemoglobin electrophoresis.
How many lobes must a neutrophil have to be considered “hypersegmented”?
Neutrophils are considered hypersegmented if there are 5 lobes in >5% of PMNs or if any PMNs have 6 lobes in their nuclei.
Which megaloblastic anemia is associated with neurologic disease?
B12 deficiency is associated with neurologic disease.
What are the MMA and homocysteine levels in B12 and folate deficiencies?
MMA and homocysteine are both elevated in B12 deficiency. In folate deficiency only the homocysteine level is increased with normal MMA.
Which general lab tests are abnormal in hemolytic states?
Bilirubin and LDH tend to be elevated in hemolytic states. Haptoglobin is low in both intravascular and extravascular hemolysis. Reticulocytes are elevated in hemolysis.
What cells are seen in the peripheral blood of patients with G6PD deficiency?
Bite cells are seen in the peripheral smear of patients with G6PD deficiency.
Which virus is implicated in the development of aplastic crisis or worsening of anemia in patients with sickle cell disease?
Aplastic crisis or worsening anemia in a patient with sickle cell disease may be caused by infection with parvovirus B19.
Which cells are seen on peripheral smear in patients with hereditary spherocytosis?
Spherocytes are seen in the peripheral smear of patients with hereditary spherocytosis. Coombs test is negative.
What is the clinical presentation of PNH?
PNH leads to variable degrees of intravascular hemolysis, which can lead to hemoglobinuria and iron deficiency.
Which tests are used to diagnose PNH?
Diagnosis of PNH is now made with flow cytometry demonstrating loss of CD55 and CD59 from the cell membrane.
Which leukemia/lymphoma is associated with autoimmune hemolytic anemia?
CLL and lymphoma are associated with autoimmune hemolytic anemia.
What is the most common neurologic manifestation of porphyria?
The most common neurologic manifestation of porphyria is neurovisceral abdominal pain.
What is the typical presentation of hereditary hemochromatosis?
Patients with hemochromatosis usually present in middle age with early signs and symptoms of iron overload including fatigue and weakness, abnormal LFTs, bronzing of the skin, diabetes mellitus, joint pain +/- crystalline arthropathy (CPPD), and erectile dysfunction.
Which test is used to diagnose hereditary hemochromatosis?
The most sensitive test to diagnosis hemochromatosis is transferrin saturation. If iron saturation is >45% consider a ferritin and genetic testing.
What disorder(s) cause a high ferritin? A high ferritin with multiple cytopenias and hemophagocytosis in the bone marrow?
Very high ferritin levels are seen in hemochromatosis, hemophagocytic lymphohistiocytosis, and adult Still disease.
Explain how aspirin and NSAIDs work to decrease platelet function.
Aspirin irreversibly acetylates cyclooxygenase and suppresses thromboxane A2. NSAIDs bind reversibly to cyclooxygenase.
At the bedside, how can you tell whether a hemostatic problem is primary or secondary?
Primary hemostatic problems generally involve platelet dysfunction or low platelet counts. They present with multiple, tiny, superficial hemorrhages leading to petechiae, purpura, ecchymoses, and mucocutaneous bleeding. Secondary hemostatic problems involve clotting factors and cause deep tissue bleeding including hematomas and hemarthroses.
What are the 4 tests initially used to evaluate a bleeding disorder? What do they measure?
Four tests to initially assess coagulation and platelet status include PT, (extrinsic and common pathways), PTT (intrinsic pathway), platelet count, and platelet function tests.
What is the usual clinical presentation of ITP in an adult patient?
The typical adult presentation of ITP is bruising, petechiae, and purpura.
What are the 1st and 2nd line treatments for ITP?
The 1st line treatment for ITP is steroids. Second line treatment is IVIg.
TTP is due to problems with which enzyme?
TTP is due to a deficiency of or inhibitor to ADAMTS13, the enzyme responsible for cleavage of ultra-long multimers of von Willebrand factor.
Which 5 clinical manifestations occur with TTP? With aHUS?
The five clinical manifestations of TTP are thrombocytopenia, microangiopathic hemolytic anemia, fever, renal failure, and neurologic changes. Atypical HUS has all of the same manifestations and lab results, except the renal manifestations occur more and neurologic manifestations occur less than in TTP.
What is the treatment of choice for TTP? For aHUS?
The treatment of choice for TTP is plasmapheresis. The treatment of aHUS is eculizumab, a monoclonal antibody that inhibits the terminal complement cascade.
Which bacterial infection is associated with diarrhea-associated HUS?
E. coli O157:H7 is associated with diarrhea-associated HUS.
What do the letters in HELLP syndrome stand for? In which patients doe it occur?
HELLP stands for hemolysis, elevated liver enzymes, and low platelets. This syndrome occurs in 20% of woman with preeclampsia and 10% of patients with eclampsia.
Does HIT type II cause bleeding or thrombosis?
HIT type II causes thrombocytopenia but is associated with thrombosis not bleeding.
What is the treatment for HIT-II?
The treatment of HIT-II is to stop all heparin products first. Then you must treat with direct thrombin inhibitors, lepirudin or argatroban.
When does post-transfusion purpura occur?
Post-transfusion purpura is rare and occurs primarily in women sensitized by pregnancy. It occurs ~1 week after transfusion and can last days to weeks.
What are the 2 most common types of vWD?
The two most common types of vWD are type 1 and type 2. Type 1 is a quantitative defect in von Willebrand factor. Type 2, which has multiple subtypes, is a qualitative defect.
What are Factor 8 activity levels in patients with vWD?
von Willebrand factor is a carrier for factor 8 and protects it from degradation. Therefore, in vWD the factor 8 levels are low.