Immunology Flashcards
Broad causes of secondary immune deficiency?
Physiological (extremes of age) Infection Treatment interventions Malignancy Biochemical and nutritional disorders
Examples of infections causing secondary immune deficiency?
HIV
Measles
Examples of treatment interventions causing secondary immune deficiency?
Immunosuppressives
Anti-cancer
Corticosteroids
Examples of malignancies causing secondary immune deficiency?
Lymphoma, leukaemia, myeloma
Metastatic cancer
Examples of biochemical and nutritional disorders causing secondary immune deficiency?
Malnutrition
Renal insufficiency
Diabetes (T1+2)
Mineral deficiencies
Definition of granuloma?
An organised collection of activated macrophages and lymphocytes
Why do granulomas form?
non-specific inflammatory response triggered by diverse antigens or foreign bodies- stimulus not removes- persistent
Differential of lung granulomas?
Sarcoidosis TB Leprosy Silicosis (other dust diseases) Chronic hypersensitivity pneumonitis Foreign bodies
2 presentations of antibody deficiencies?
Recurrent bacterial infection
Antibody mediated autoimmune disease (e.g. ITP, haemolytic anaemia)
Function of natural killer cells?
Kill cells that lack MHC (molecules on surface)- no antigen specificity
Primary causes of recurrent infections and low immunoglobulins?
CVID- common variable immune deficiency
Specific antibody deficiency (IgA very common!)
Secondary causes of recurrent infections and low immunoglobulins?
Protein loss- nephrotic syndrome
Low protein production- CLL, myeloma, NHL
What is complement?
Proteins secreted by liver that interact with pathogens to mark them for destruction by phagocytes
(promotes inflammation)
Examples of live attenuated vaccines?
MMR Chickenpox Yellow fever Rotavirus BCG
Examples of inactivated whole cell vaccines?
Polio
Hep A
Rabies
Cholera
Examples of inactivated fractional vaccines?
Hep B Influenza HPV Anthrax Diphtheria Tetanus Haemophilus influenza type B
How do vaccinations produce memory?
Generate long-lived memory B cells (last years) and effector T cells/memory T cells
What does immune memory cause during secondary infection?
Ability to clear infection during incubation period, before the onset of clinical features, by rapidly producing IgG
Pros of inactivated vaccines?
Quick and easy and safe
Cons of inactivated vaccines?
Not very potent- don’t stimulate good immune response
Pros of live attenuated vaccines?
Strong, localised response
One dose
Cons of live attenuated vaccines?
May cause infection
Must be handled carefully
What type of hypersensitivity is a hyperacute rejection of transplant and why does it occur?
Type II hypersensitivity
Due to preformed antibodies
2 types of acute transplant rejection?
Acute cellular rejection (type IV hypersensitivity)
Acute vascular rejection (type II hypersensitivity)
What does chronic allograft failure lead to?
Fibrosis and scarring
What are “toll-like receptors” and what do they respond to?
Allow innate recognition of invaders, respond to PAMPS (pathogen-associated molecular patterns), then allow cytokine/IF1 release
Where are “toll-like receptors” expressed?
Phagocytes + dendrites
Function of TNF-alpha?
Immediate-early “alarm” signal in response to stressors (microbes, stress, chemicals etc.)
How do TNF-inhibitors work?
By blocking pro-inflammatory cytokines
How do biologic drugs work?
Artificial antibodies that block the body’s own proteins
passive immunisation
Examples of biologics?
Adalimumab
Pembrolizumab
Secukinumab
How are biologics metabolised?
THEY AREN’T
natural proteins so not metabolised by body
Safe in renal/liver disease
Do biologics act as immunosuppressants?
NO
Autoantibody for coeliac?
Tissue transglutaminase IgA antibody
Autoantibody for myasthenia gravis?
Anti-acetylcholine receptor antibody
Autoantibody for rheumatoid arthritis?
Anti-CCP
Autoantibodies for SLE?
Anti-dsDNA, anti-Sm, ANA
Autoantibodies for Sjogren’s?
Anti-Ro, anti-La
Is methotrexate an immunosuppressant?
NO (anti-inflammatory)
Safe in cancers/TB
When is methotrexate contraindicated?
Liver disease
Pregnancy
Autoantibody for myositis?
Anti-Jo
Autoantibody for MCTD?
Anti-RNP
Autoantibody for limited systemic sclerosis?
Anti-centromere
Autoantibody for diffuse systemic sclerosis?
Anti-Scl-70
Autoantibodies for APS?
Anti-cardiolipin and lupus anti-coagulant
Autoantibody for small vessel vasculitis?
ANCA