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
MHC Class II: HLA-D
-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?
-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
WE CAN COLLECT ENOUGH HSC
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