Immunology Flashcards
(27 cards)
causes of immune deficiency
Physiological immune deficiency
- extremes of ages,
- prematurity
Infection
- HIV, measles
Treatment Interventions
- immunosuppressive therapy,
- anti - cancer agents,
- corticosteroids
Malignancy
- cancers of immune system - lymphoma ect
- metastatic tumours
Biochemical and nutritional disorders - malnutrition - renal insufficiency/dialysis - diabetes mineral deficiencies (iron, zinc)
what is a granuloma
organised collection of activated macrophages and lymphocytes
Differentials of lung granuloma
sarcoidosis TB silicosis hypersensitivity pneumonitis foreign bodies
Formation of a granuloma
- non specific inflam. response triggered by antigenic agents or foreign materials
- leads to T lymphocyte activation and macrophages
- failure of removal of stimulus leads to persistently activated cytokines
- organised collection of persistently activated cells
Presentation of antibody deficiencies
Recurrent bacterial infections - recurrent URTI an LRTI - recurrent GI infections Viral infections (less common) Antibody mediated disease - ITP - Autoimmune haemolytic anaemia
what is complement
proteins that are constantly secreted by the liver to act as a sticky coat for intruders to boost immune defence
C3 splits into a and b, what does each do
C3b - opsonisation - coats bacteria to make it more desirable by phagocytes
C3a - chemotaxis and anaphylatoxin release, calls in the troops
Features of NK cells
lack MHC molecule on cell surface no need to for antigen specificity no long term memory NK cell defect predisposes to (CMV, HPV, HSV) used to eliminate cancer cells
what are toll - like receptors
Receptors expressed on phagocytes and dendrites which act as burglar alarm for microbes
Respond to PAMPs
what does activation of toll like receptors result in
secretion of pro - inflammatory cytokines and type 1 interferon
what is the function of biologic drugs
artificial antibodies that block the body’s own proteins
Adalimumab is a biologic drug, what is its molecular target, main action and its use
Anti TNF
Anti - inflammatory
Rheumatic and inflammatory disease
what are the 4 types of transplant rejection?
Hyperacute rejection
Acute cellular rejection
Acute vascular rejection
Chronic allograft failure
Describe hyperacute transplant rejection
Time: mins - hrs
Pathology: thrombosis and necrosis, type 2 hypersensitivity
Treatment: none
describe acute cellular rejection
Time: 5 - 10 days
Pathology: cellular infiltration, type 4 hypersensitivity
Mechanism: CD4/8 t cells
Treatment: immunosuppression
describe acute vascular rejection
Time:5-30 days
Pathology: vasculitis, type 2 hypersensivity
Treatment: immunosuppression
describe chronic allograft failure
Time: more than 30 days
Pathology: fibrosis, scarring
Mechanism: immune and non - immune
Treatment: minimise drug toxicity, hypertension, hyperlipidaemia
Basic mechanism of immunisation
vaccination produces memory in B and T cells
What is the mechanism of B cells in vaccinations?
Long lived memory B cells are generated in primary immune responses and can survive for years after antigen is eliminated
The cells rapidly re - activate in response to a second encounter of the same antigen:
- clonal expansion
- Differentiation into plasma cells
- Antibody production
what is the mechanism of action of T cells in vaccinations?
Stimulation of rare naïve T cells which induces a strong T cell response in 14 - 21 days, most cells undergo apoptosis but some become memory T cells
Which antibody response time is sped up in a secondary infection?
IgG
what are the 2 types of vaccines
Inactivated vaccines - whole cell vaccines - fractional vaccines Live attenuated vaccines - viruses - bacterial
Give examples of inactivated vaccines
- whole cell - polio, hep A, rabies, cholera, pertussis
- fractional vaccines - Hep B, influenza, HPV
Give examples of live attenuated vaccines
Viruses - MMR, chickenpox, yellow fever, rotavirus, smallpox, polio
Bacterial - BCG, oral typhoid
