Transplantation Immunology Flashcards
One of the MOST POLYMORPHIC
gene system known
Human
Leukocyte
Antigen
in human leukocyte antigen, Associated protein is coded in the
______ in the
major histocompatibility complex
short arm of chromosome 6
Can occur in special case in which
immunocompetent tissue is
transplanted into an
immunocompromised host (Bone
Marrow, Thymus, Fresh Whole Blood)
Graft vs
Host
Disease (GvHD)
T cells from the transplant recognize
the host MHC molecules as non
-self
and attack the host
gvhd
Preformed antibodies and complement
that reacts with donor
Hyperacute
“White graft”
Reactivation of sensitized T cells
Pre-sensitized T cells; due to low level of
antibody present in the body in
pretransplant period
Accelerated
Primary activation of T cells
Development of allogenic reaction to
donor Ag
Acute
Causes are unclear , antibodies, immune
complex, slow cellular reaction, recurrence
of disease; side effects of
immunosuppressive drugs
Chronic
HLA Typing in
Laboratory
- DNA sequencing (Polymerase Chain
Reaction) - Serological assay
- Mixed lymphocyte culture / Mixed
lymphocyte reaction (MLC/MLR) - Crossmatching
– Amplification and specific probes to
detect different alleles
– Highly specific / sensitive
– Method of choice
DNA SEQUENCING (POLYMERASE CHAIN
REACTION)
– Cells from the donor and recipient are
reacted with a battery of antibodies,
each one of which is specific for a
different class I and II protein
– Complement is then added, and any
cell bearing an MHC protein
homologous to the known antibody
will lyse
– Satisfactory in most cases
SEROLOGICAL ASSAY
“Stimulator” lymphocytes from a potential donor are first killed
by radiation and then mixed with live “responder” lymphocyte
from the recipient
- MLC/MLR
Result: the greater the amount of DNA synthesis in the
responder cells, the more foreign are the Class I and II MHC
proteins of the donor cell
– The fetus is an allograft that is not rejected
– Trophoblast layer of the placenta does not allow maternal T cells
to enter the fetus
CROSSMATCHING
KINDS OF IMMUNOSUPRESSIVE AGENTS
*Corticosteroids
*Antimetabolic Agents
*Calcineurin Inhibitors
*Monoclonal antibodies
*Polyclonal antibodies
To suppress antigraft immune response in solid-organ and stem cell
transplantation
Increase susceptibility to infection, malignancies , and other
associated toxic side effects
IMMUNOSUPPRESSIVE AGENTS
can cause uninhibited cell division if their
expression is altered or if they are mutated
into oncogenes
- PROTO-ONCOGENES
- TUMOUR SUPPRESSOR GENES
- PROTO-ONCOGENES
are characterized by slow growth restricted
anatomic location and do not cause deatH
BENIGN NEOPLASM
MALIGNANT NEOPLASM OF
– is often referred as cancer or tumor.
They are
characterized by:
a. Anaplasia in which cells lose their differentiating features
b. Invasion of the body
c. Metastatic spread which can result in death
Often named by adding the suffix –oma (lipoma) to the cell
type but there are exceptions such as lymphomas,
melanomas, hepatoma
BENIGN TUMOR