Heme Onc Flashcards
What is the main difference in effect between unfractioned heparin and LMWH?
Both of them can bid to AT3 to increase its activity against factor Xa.
Only unfractionated heparin is able to bind to both AT3 and thrombin, thereby allowing antithrombin to inactivate thrombin.
What is the most common viral cause for aplastic crisis for sickle cell patients?
Parvovirus B19
What effect might fibrinolytics have on heart rhythm?
They may cause a repurfusion arrhythmia on arterial reopening. These arrhytmias are usually benign.
What is the presentation for Hemolytic Uremic Syndrome? (3) What is the etiology?
- Microangiopathic hemolytic anemia
- Thrombocytopenia
- Renal insufficiency
Result of 0157:H7 E.coli, usually in undercooked ground beef
Hepcidin
- What is it/ what does it do?
- When is it released?
- Hepcidin is an acute phase reactant synthesized by the liver that acts as the central regulator of iron homeostasis. It prevents release of iron bound by ferritin
- High iron levels/ inflammatory conditions increase hepcidin synthesis. Hypoxia and increased EPO lower hepcidin levels
What is the effect of low hepcidin levels?
Low hepcidin levels increase intestinal iron absorptin and stimulate iron release by macrophages
Hairy Cell Leukemia
- What type of neoplasm?
- Presentation?
- Indolent B-cell neoplasm
- MIddle-aged men w/ bone marrow /fibrosis (leading to dry tap) + massive splenomegaly (due to red pulp infilitration) + cytoplasmic projections on lymphocytes
What is the specific deficiency in patients with Glanzmann thrombasthenia?
(GP) IIb/IIIa, needed for platelet aggregation
Abciximab MOA
It blocks the GP IIb/IIIa receptor, which normally promots platelet binding to fibrinogen
Paroxysmal nocurnal hemoglobinuria is result of an acquired mutation in what gene? What inhibitor proteins is absent and/or deficient as a result?
Mutation in the PIGA gene. This leads to absence of the GPI anchor that normally protects the RBC from complement, and associated deficiency of CD55/CD59 complement inhibitor proteins.
Dactylitis
(What is it and what is it a common presentation of?)
Painful swelling of the hands and feet
It is a common presentation of sickle cell in young children.
What effect does sickling (in SCD) have on labs?
Leads to
- Increased indirect bilirubin
- Increased lactate dehydrogenase
- Decreased haptoglobin (binds free hemoglobin and is then removed by the spleen)
What drugs do you give to reverse heparin effects? Warfarin effects?
Heparin: protamine sulfate
Warfarin: Vitamin K and Fresh Frozen Plasma (FFP)
X-linked (Bruton) agammaglobulinemia
- Caused by what?
- Effect on germinal center formation
- Presentation?
- Caused by a defect in B cell maturation, resulting in the absence of mature B cells with severe defiency of all Ig types. T cells remain fxnal and intact!
- No B cells = no germinal center formation
- Recurrent infxn in setting of intact T Lymphocyte function
Distinguish Precursor B-ALL from precursor T-ALL
This can only be done via immunophenotyping
B-ALL: TdT+, CD10+ and CD19+
T-ALL: TdT+, CD1a+, and + for T-cell markers (CD2 , 3, 4, 5, 7, and 8)