ICL 10.1 & 10.2: Leukemia Flashcards
(116 cards)
which cell types are in the myeloid cell line?
platelets
RBCs
granulocytes: neutrophils, basophils, eosinophils
monocyte
macrophages
which cell types are in the lymphoid cell line?
NK cells
B cells –> plasma cells
T cells
What differentiates leukemia from lymphoma?
leukemia arises from lymphoid or myeloid cells, starts in the bone marrow, and then spreads to the blood stream
lymphoma arises from lymphocytes, and starts in lymph nodes then spreads to blood stream
but both are malignant diseases of hematopoietic cells
what are the two major groups of leukemias?
- acute leukemia vs. chronic leukemia
2. myeloid vs. lymphoid leukemias
what are the main characteristics of acute leukemias?
- appear suddenly
- have a devastating clinical course if untreated
- composed of very immature hematopoietic cells
what are the main characteristics of chronic leukemias?
- much more indolent
- may persist for years even without treatment
- composed of cells at a more mature stage of development
what is the marker for lymphoid vs. myeloid leukemia?
Tdt is a marker for lymphoid leukemia
MPO is a marker for myeloid leukemias
what does ALL stand for?
Acute Lymphoblastic Leukemia
what is ALL?
a malignant entity in which very early lymphocyte precursors called lymphoblasts proliferate in the bone marrow and blood
these malignant lymphoblasts divide very quickly, filling up the bone marrow and crowding out normal hematopoietic precursor cells, leading to serious consequences for the patient if not treated immediately
so eventually the amount of mature functioning cells decreases a lot - so you have less RBCs, platelets, everything!
what are the three main types of lymphocytes?
- B cells (adaptive immune system)
- T cells (adaptive immune system)
- NK cells
(innate immune system)
what are B cells?
make antibodies
in charge of the humoral arm of the adaptive immune response
what are T cells?
they use cytokines and other cell surface molecules to mediate the cellular arm of the adaptive immune response
what cells are malignant in ALL?
acute lymphoblastic leukemia comes from either malignant B cell or T cell precursors
NK cells and their precursors have their own malignancies that are separate from ALL
what’s the clinical presentation of ALL?
- neutropenia = bacterial infections, fever
- anemia = fatigue, no energy
- thrombocytopenia = bleeding, petechiae, epistaxis, gum bleeding
- hepatosplenomegaly
- lymphadenopathy
- testicle enlargement (esp. ALL)
- bone pain
- possibly asymptomatic
what population is ALL more common in?
MUCH more common in children
also associated with Down’s Syndrome
T cell vs. B cell ALL
B cell ALL – typically bone marrow involvement first
T cell ALL – Lymph node involvement first
what does the bone marrow of an ALL patient look like?
diffuse, massive proliferation of lymphoblasts
the lymphoblasts are medium-sized cells with a super high nuclear/cytoplasmic ratio and fine chromatin
basically there’s just a ton of big plain purple cells with like no cytoplasm (go look at slide 24)
nucleoli can also be seen which is typically not visible in more mature cells
what does the CBC of an ALL patient look like?
severely increased WBC count because you’re making all these immature lymphoblasts (like 70,000/mmˆ3!!!)
normal blood cells like RBCs, normal WBCs, and platelets are usually decreased in number
what is flow cytometry allow us to do?
it enables us to determine immunophenotype
this test is looking for specific cell surface antigens
these surface markers sometimes change as the cell matures
flow cytometry helps us determine what kind of leukemia and lymphoma it is!
also it’s not invasive…
what are the surface proteins found on T cells?
CD3 and CD5
flow cytometry will show you which surface markers on which molecules to help you identify them!
which are the surface proteins found on helper T cells?
CD4
flow cytometry will show you which surface markers on which molecules to help you identify them!
which are the surface proteins found on cytotoxic T cells?
CD8
flow cytometry will show you which surface markers on which molecules to help you identify them!
which are the surface proteins found on B cells?
Ig, CD10, CD23, CD19, CD20, CD21
flow cytometry will show you which surface markers on which molecules to help you identify them!
which cell marker is specific to lymphoblasts and therefore important in ALL diagnosis?
TdT
all lymphoblasts express TdT!! (terminal deoxynucleotidal transferase)
this is supposed to disappear as cell matures
so if there’s a lot of TdT it tells you that there’s lots of immature cells
then you can do flow cytometry to determine if it’s B cell ALL (CD10, 19, 21, 23) or T cell ALL (CD2, 3, 4, 8)