Hypersensitivity Flashcards
How to determine if B cell monoclonal proliferation?
including flow cytometry, serum protein electrophoresis with immunofixation electrophoresis (e.g. monoclonal spike in myeloma), kappa and lambda immunostaining, and kappa and lambda in situ hybridization study, B lymphocyte immunoglobulin gene arrangement analysis
How to determine if T cell monoclonal?
TCR gene rearrangement analysis
flow cytometry studies, or by analysis of immunostains for T lymphocyte markers on paraffin embedded tissue.
Flow cytometry performed on what
fresh, unfixed tissue
5 pillars of cancer treatment
Surgery Chemotherapy Radiation Targeted therapies Immunotherapy
Protein serum electrophoresis - what do you see in cirrhosis, myeloma, waldenstrom’s macroglobulinemia
In cirrhosis, see elevated gamma fraction but with kappa and lambda.
In myeloma, see only kappa and peak in gamma.
In Waldenstrom’s macroglobulinemia - kappa light chain restriction, M speak monoclonal
Define hypersensitivity reactions
Individuals previously exposed to an antigen are said to be sensitized; upon repeat exposure(s), some individuals will develop an excessive, injurious pathologic immune reaction to the antigen. These pathologic immune reactions are called hypersensitivity reactions, and are the basis of the pathology associated with immune diseases.
type 1 hs
immediate
type 2 hs
antibody-mediated
type 3 hs
immune complex-mediated
type 4 hs
cell-mediated
type 1 hs prototypic disorder
anaphylaxis, allergies, bronchial asthma
type 2 hs prototypic disorder
autoimmune hemolytic anemia, goodpastures
type 3 hs prototypic disorder
SLE, serum sickness, arthus
type 4 hs prototypic disorder
contact dermatitis, MS, DM 1, RA, IBD, tb
Type 1 hs definition
rapid immunologic reaction occurring within minutes after an antigen combines with antibody bound to mast cells in individuals previously sensitized to the antigen (allergic reaction).
Type 1 hs mediated by
is typically mediated by IgE antibody-dependant activation of mast cells, with degranulation and release of mast cell contents.
Type 1 hs steps
Sensitization (initial exposure to antigen – activation of B cells w/ production of IgE attaching to mast cells)
Repeat exposure causing mast cell degranulation
Late phase reaction
What do mast cells release
release of chemical mediators, causing vasodilation, vascular leakage, smooth muscle spasm, and recruitment of leukocytes, particularly eosinophils.
What do eosinophils release
secrete major basic protein and eosinophil cationic protein, which are toxic to epithelial cells.
what is late phase reaction
Activated eosinophils and neutrophils also activate mast cells to release mediators, amplifying and sustaining the inflammatory response without additional exposure to the triggering antigen (late phase reaction).
atopy
predisposition to develop immediate hypersensitivity reacti
Antigens that elicit allergic reactions
allergens
hygiene hypothesis
Incidence of allergic diseases is increasing. As this seems to be related to decreasing infections in early life, some have postulated that improved hygiene has diminished exposure to microbial antigens in early life which “educate” the immune system, setting the stage for subsequent pathologic allergic responses later in life