When the immune system goes wrong Flashcards
(21 cards)
what is immediate hypersensitivity and what is it mediated by
allergy
mediated by IgE, mast cells and Th2 responses
What is the immediate hypersensitivity response due to
mast cell degranulation and histamine release. If in skin->wheal and flare
What is the Th2 response to allergenic disease
pollen taken up by APC->processed and presented as peptides to T cell receptors on CD4->activation leads to Th2 response->B cell activated->class switch to IgE and differentiate to plasma cells->when pollen arives, binds to IgE on surface mast cell->potent activation of stimulus for mast cells which degranulates all of inflammatory mediators diffsued out into local areas->symptoms=sneezing, wheal+flare
Common diseases and therapies
Diseases-asthma, perennial rhiniitis, allergic eczema
Therapies-antihistamines, beta 2 adrenoreceptor antagonist, corticossteroids
Rare diseases and therapies
Disease: anaphylaxis
Therapies: desensitisation, monoclonal antibody
Autoimmunity what
loss of immunological tolerance to self components
What are the two types of autoimmune diseases and give examples of it
organ specific-type 1 diabetes, grave’s disease
non organ specific-rheumatoid arthritis, systemic lupus erythematosus
What is autoimmunity
Loss of immunological tolerance to self components
what are serum antibodies used for
diagnostic tool, monitoring disease activity, predicting future disease, may be pathogenic
(usually IgG class)
What is the proof of autoimmunity
Passive transfer of disease by immune effectors (e.g. T cells, antibodies)
Clinical responsiveness to immune suppression or reestablishment of tolerance
How does grave’s disease work
usually thyroxine act as feedback to prevent excess TSH but thyroid gland keep making thyroxine in unregulated way->hyperthyroidism->bulging eyes, fast heart rate, weight loss, hyperactivity
How does myasthenia gravis work
patients develop autoantibodies against ACh receptor->damage receptor->transmission impaired, insufficient engagement with ACh receptor-> no or poor contraction causing muscular weakness and fatigue
How can autoantibodies be passed on from mother to child
if mother has grave’s disease, IgG antibodies against TSH receptor passed onto child. Same with myasthenia gravis
How is type 1 diabetes T cell mediated
B cell autoantigens taken up by APC and presented to CD4->activation of Th2->mediate inflammation
B cell present autoantigen directly to CD8->kills B cell
Failure Treg to suppress
Are primary and secondary immunodeficiencies inherited/acquired and are they rare/common
primary=inherited defect=rare
secondary=acquired defect=common
Are primary and secondary immunodeficiencies inherited/acquired and are they rare/common
primary=inherited defect=rare
secondary=acquired defect=common
give examples of primary immune deficiencies and what are they caused by
Di George-thymus doesn’t form
SCID-Pre B and Pre T cells don’t form, lack of cytokines and surface receptors
CGD-neutrophils are meant to be bacteriocidal by reactive O2 compound but O2 compound doesn’t form due to single gene defect. Surround bacteria cell but not kill
Hypergammaglobulinemia-single gene defect of CD40 ligand on T lymphocyte->absence means can’t communicate with B lymphocyte->productive B lymphocyte response not made->plasma cells not develop
How does AIDS arise from HIV and how can it be treated
virus infects CD4 through CD4 receptor->CD4 no. decline->antiviral CD8 brings CD4 infection under control to extent->HIV infection+antiviral cytotoxic CD8 means that CD4 wiped out->CD8 decline too
Highly Active Antiretroviral Therapy
What is iatrogenic immune deficiency
Immune deficiency caused by medical treatment therapy. Often opportunistic infections caused by monoclonal antibody therapy
What causes cancer
Too much immune surveillance (Treg), immune surveillance to combat cancer cells stop working
How can cancer be treated
PDL1 on cancer cell and PD1 on effector cells can interact if there is antibody to PD1 or PDL1 as the stop signal for immune surveillance can be taken away->cancerous cells removed
