Flashcards in WBC disorders Deck (22):
What is hairy cell leukemia?
A neoplastic proliferation of mature B cells characterized by hairy cytoplasmic processes
How is hairy cell leukemia diagnosed?
These cells show hairy cytoplasmic processes on blood smear and are positive for tartrate-resistant acid phosphatase (TRAP) stain.
What are the clinical features of hairy cell leukemia?
Everything can be summed up as TRAP:
--the cells are TRAP positive
--marrow fibrosis (the cells get "trapped" in the marrow--> pancytopenia)
--(hepato)splenomeglay (accumulation of hairy cells in the red pulp of the spleen--they get "trapped")
--LAD is usually absent
How do you treat hairy cell leukemia?
adenosine deaminase inhibitor; leads to toxic accumulation of adenosine in neoplastic B cells
the Philadelphia chromosome
CML (bcr-abl hybrid)
Burkitt lymphoma (c-myc activation)
14 = Fc heavy chain gene
Mantle cell lymphoma (cyclin D activation)
Follicular lymphomas (bcl-2 activation)
M3 type of AML (responsive to all-trans retinoic acid)
Where does fetal hematopoiesis occur?
Yolk sac 3-8 weeks (3rd week)
Liver 6 weeks to birth (one month)
Spleen 10-28 weeks (2-4 months)
Bone marrow 18 weeks to adult (after 4 months)
What units is fetal hemoglobin composed of? How does its affinity for oxygen compare to adult Hb and why?
Fetal hemoglobin consists of alpha2gamma2
It has a higher affinity for oxygen than HbA (adult Hb) due to less avid binding of 23BPG (recall: 2,3BPG shift the oxygen dissocation curve to the right, promoting oxygen unloading).
This allows fetal Hb to extract oxygen from maternal Hb across the placenta
What are some basic principles of myeloproliferative disorders?
(1) These disorders are a neoplastic proliferation of mature cells of the myeloid linage
(2) diseases of late adulthood (avg. age is 50-60)
(3) sub-categorized based upon which myeloid cell is predominantly produced.
(4) result in hypercellular bone marrow, and increased WBC (due to an increase in the number of granulocytes)
What are the complications of Myeloproliferative Disorders?
(1) Increased risk of hyperuricemia, sue to the high turnover of cells
(2) progession to marrow fibrosis
(3) transformation to Acute Leukemia
What is chronic myeloid leukemia (CML)?
A neoplastic proliferation of mature myeloid cells, especially granulocytes and their precursors.
What cell type is characteristically increased in CML?
What is the cause of CML?
t(9;22) translocation. (Philadelphia chromosome, bcr-abl fusion protein with increased tyrosine kinase activity)
What is the first-line treatment of CML?
Clinical features of CML
enlarging spleen suggests the disease is getting worse, may herald the transformation to to acute leukemia (AML in 2/3 of the cases, ALL in 1/3)
What is a leukemoid reaction?
It is a reactive neutrophilic leukocytosis
ie, an acute inflammatory response to an infection
How can CML be distinguished from a leukemoid reaction?
(1) presence of t(9;22) -- absent in leukemoid reaction
(2) Increased basophils -- absent in leukemoid reaction
(3) Negative leukocyte alkaline phosphatase (LAP) stain --granulocytes in a leukemoid reaction are positive for LAP)
What is polycythemia vera (PV)
A neoplastic proliferation of mature myeloid cells, particularly RBCs