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Flashcards in Zlotnik 2 Deck (18):

Explain the ABO blood groups, how are they derived?

A and B antigens are oligosaccharides present in RBC
-combinations are A+B, A or B, neither A nor B
--A type (anti-B antibodies)
--B type (ant-A antibodies)
--AB type (no Abs present) (universal acceptor)
--O type (both A and B Abs present) (universal donor)


What are the name of the Abs present in the plasma of blood?

Agglutinins, causes A or B expressing erythrocytes to agglutinate


What is Rh factor? How is it related to erythroblastosis fetalis?

-factor Rh can be + or -
-in contrast to ABO groups, Rh- do not develop Abs against Rh unless exposed to cells bearing this antigen
-erythroblastosis fetalis is disease where there is agglutination and phagocytosis of the newborn's RBC
-happens when mother is Rh- and father is Rh+, fetus is then Rh+
-Mother is sensitized to Rh antigen and may start affecting the 2nd and subsequent newborn
-mother's anti-Rh Abs diffuse to fetus through placenta and cause RBC agglutination


How to prevent erythroblastosis fetalis?

-D antigen of Rh group is responsible for sensitization of the mother
-we can treat EF by administering anti-D antigen antibody to mother
-anti-D antibody also administered to prevent sensitization to the D antigen


Why have bone marrow transplant? What is the problem?

Can correct defect in hematopoiesis (such as those who have been treated by chemotherapy)
-problem is Graft vs Host Disease


What is the major histocompatibility complex? (MHC)

Cell surface molecules present in ALL cells of our body
-identify the cells that belong to 'our organism'
-HLA-A, B, and C


What and where is the thymus?

Organ that makes T cells
-sits above the heart
-Active early on but begins to disappear as people hit their early teens


MHC Class I vs Class II

MHC Class I: HLA-A, B, C
-single chain molecules associate with beta2 microglobulin
-expressed in ALL cells
-presents antigen to CD8 T cells to start cytotoxic immune response

-two chain molecules (alpha and beta)
-expressed in macrophages, dendritic cells, and B cells
-presents antigen to CD4 T cells to start immune response


What is lymphopoiesis?

-Lymphoid precursors originate in bone marrow (migrate to thymus)
-in thymus, they mature and exit as CD4 or CD8 T cells (immunocompetent)
-they can now distinguish self from non-self

B cells mature in bone marrow


What is an allogeneic MHC?

non-self MHC molecules 'look' similar to self MHC + antigen
-creates immune response when there is no actual antigen, release of cytokines can be problematic


What happens in graft vs. host disease?

common in bone marrow transplants:
-T cells of grafted cells recognize host as 'foreign' and start to produce cytokines
-this causes systemic symptoms of inflammation...can affect liver, skin, and mucosa


Chronic vs acute leukemia?

Chronic: slow and from differentiated/partially differentiated leukocytes

Acute: rapid and from undifferentiated precursors


How can we correct the problems with bone marrow transplants?

-Chronic lymphomas
-other altered hematopoietic conditions
-autologous bone marrow transplant is best
-limitation is obtaining enough hematopoietic stem cells (HSC) to transplant to patient

-we can take a healthy source of HSC, treat the patient, then reintroduce the HSC


What are chemokines?

small proteins made by: leukocytes, lymphocytes, stromal cells
-they 'guide' cells to destinations
-can also 'keep' cells in certain tissues (ie. CXCR4/CXCL12 keep HSC in bone marrow)
-CCR5 and CXCR4 are 'portals' of entry for HIV


What is unique about CCR7? CXC and CC chemokines?

Needed for cell to enter lymph node (direct T cells)
CXC: recruit neutrophils
CC: recruit monocytes and T cells (ie CCR5 and CCR7)


What is Plerixafor (Mozobil)? Uses?

-Inhibits CXCL12/CXCR4 (CXCR4 antagonist) interaction and results in large release of hematopoietic stem cells into circulation; recovered by leukapheresis
-synergizes with G-CSF
-approved for lymphomas and multiple myeloma
-eliminates concerns of graft vs. host disease caused by allogeneic transplant



Which leukocyte can we remove with the least affect to our system? Why are monoclonal Abs good?

B cells, we can administer Abs manually

Monoclonal Abs are very specific


What are antibody drug conjugates?

Works for Hodgkin lymphoma
-uses Abs combined with cytotoxic drug
-drug is released when Abs internalized
-minimal side effects