Heme/Onc Flashcards
Define anisocytosis
Varying sizes of RBCs
Define poikilocytosis
Varying shapes of RBCs
Define reticulocyte
immature RBC
What is contained within the dense granules of platelets?
ADP and Ca
What is contained within the alpha granules of platelets?
vWF and fibrinogen
What is the vWF receptor on platelets?
GpIb
What is the fibrinogen receptor on platelets?
GpIIb/IIIa
What is the WBC differential from highest to lowest amount?
Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils (“Neutrophils Like Making Everything Better”)
Hypersegmented PMNs are seen in what?
B12/folate deficiency
Which cell type is the precursor for a macrophage?
Monocyte
What activates a macrophage?
gamma-IF
Eosinophils defend against which type of infection?
Helminth
What are the causes of eosinophilia?
Neoplasia, Asthma, Allergic processes, CT diseases, Parasites (invasive) (“NAACP”)
Basophils mediate what?
Allergic reactions
What three things do basophils contain?
Histamine, heparin, and leukotrienes
What three things do mast cells contain?
Histamine, heparin, and eosinophil chemotactic factors
What is the MOA of Cromolyn sodium?
Prevents mast cell degranulation - used for asthma prophylaxis
Which two receptors do dendritic cells express?
MHC Class II and Fc receptors
Dendritic cells in the skin are called what?
Langerhans cells
B cells differentiate into what?
Plasma cells
Plasma cells release what?
Antibodies and memory cells
Cytotoxic T cells express which CD type and recognize which MHC?
CD8, MHC I
Helper T cells express which CD type and recognize which MHC?
CD4, MHC II
What is Hemophilia A?
Deficiency of factor VIII
What is Hemophilia B?
Deficiency of factor IX
Which form of VitK acts as a cofactor for the coagulation cascade: oxidized or reduced?
Reduced
VitK is a cofactor for what?
Precursors of factors II, VII, IX, X, and proteins C and S
What carries and protects factor VIII?
vWF
Antithrombin inhibits activated forms of which factors?
II, VII, IX, X, XI, XII
What is the MOA of warfarin?
Inhibits the enzyme VitK epoxide reductase which reduces VitK
What is the MOA of heparin?
Enhances the activity of antithrombin
What are the principal targets of antithrombin?
Thrombin and factor Xa
Protein C does what?
Cleaves and inactivates Va and VIIIa
What is the very first step of primary hemostasis?
Transient vasoconstriction via neural reflex and endothelin release from endothelial cells
WP inside endothelial cells holds what?
vWF and P-selectin
TxA2 is a derivative of what?
COX
What is the MOA of aspirin?
Inhibits COX and TXA2 synthesis
What is the MOA of ticlopidine and clopidogrel?
Inhibit ADP-induced expression of GpIIb/IIIa
What is the MOA of abciximab?
Inhibits GpIIb/IIIa directly
What is the MOA of ristocetin?
Activates vWF to bind to GpIb
Does infection cause a high or low ESR?
high
Does pregnancy cause a high or low ESR?
high
Does CHF cause a high or low ESR?
low
Does autoimmune disease cause a high or low ESR?
high
Do malignant neoplasms cause a high or low ESR?
high
Does HbSS cause a high or low ESR?
low
Does microcytosis cause a high or low ESR?
low
Does polycythemia cause a high or low ESR?
low
Does GI disease cause a high or low ESR?
high
Does hypofibrinogenemia cause a high or low ESR?
low
Is petechiae usually indicative or a qualitative or quantitative disorder of platelets?
Quantitative (thrombocytopenia)
What is the most common cause of thrombocytopenia in children?
Immune thrombocytopenia (ITP)
What is the most common cause of thrombocytopenia in adults?
Immune thrombocytopenia (ITP)
What is the pathophysiology of ITP?
Auto-IgG against GpIIb/IIIa
What lab finding is associated with ITP?
More megakaryocytes on bone marrow biopsy. Low platelet count. Normal PT/PTT.
What is the common presentation of acute ITP?
Children, weeks after a viral illness. Self-limited.
What is the common presentation of chronic ITP?
Females of child-bearing age. May be primary or secondary (SLE). IgG can cross placenta.
What are the treatment options for ITP?
- Corticosteroids - adults with chronic form usually relapse
- IVIG - in acute setting with symptomatic bleeding
- Splenectomy - remove source of Abs and site of destruction - performed in refractory cases
What is the pathogenesis of microangiopathic hemolytic anemia?
Pathologic formation of platelet microthrombi in small vessels causes shearing stress of RBCs passing through (schistocytes) which causes hemolysis.
What are the lab findings of microangiopathic hemolytic anemia?
Anemia, low platelet count
What are a few underlying causes of microangiopathic hemolytic anemia?
TTP and HUS
What is the cause of thrombotic thrombocytopenic purpura (TTP)?
Inhibition or deficiency of ADAMTS 13 (usu an auto-Ab) which is necessary to degrade multimers of vWF into monomers. This causes increased platelet aggregation and thrombosis. Causes a form of angiopathic hemolytic anemia.
What are the lab findings of TTP?
Schistocytes and increased LDH
What are the symptoms of TTP?
Pentad of neurologic and renal symptoms, fever, thrombocytopenia, and microangiopathic hemolytic anemia.
What is the treatment of TTP?
Exchange transfusion and steroids
The hematopoietic stem cells expresses which CD?
CD34
What is Bernard-Soulier syndrome?
Deficiency of GpIb receptors
What can an acanthocyte (spur cell) indicate?
Liver disease, abetalipoproteinemia
What can basophilic stippling indicate?
Anemia of chronic disease, alcohol abuse, lead poisoning, thalassemias
What can a bite cell indicate?
G6PD deficiency
What can a ringed sideroblast indicate?
Sideroblastic anemia
What can a schistocyte indicate?
DIC, TTP/HUS, traumatic hemolysis, micropathic hemolytic anemia
What can a teardrop cell indicate?
Bone marrow infiltration
What can a target cell indicate?
HbC disease, asplenia, liver disease, thalassemia
Where is iron absorbed?
Duodenum - enterocyte
What is Plummer-Vinson syndrome?
Triad of iron deficiency anemia, esophageal webs, and atrophic glossitis.
Sideroblastic anemia is due to what?
Defect in heme synthesis (usually due to X linked defect of ALAS)
Lead leads to anemia by denaturing what?
ALAD and ferrochelatase
In sideroblastic anemia, where is the Fe accumulating?
In the mitochondria
What is the treatment of sideroblastic anemia?
B6
Alpha thalassemia is due to what?
alpha globin gene deletions (chromosome 16)
Beta thalassemia is due to what?
point mutations in splice sites and promoter sequences leading to less beta globin synthesis on chromosome 11