Immunology Flashcards
Granulocytes Mnemonic
Never Let Mom Eat Beans Neutrophils - 60% Lymphocytes - 30% Monocytes - 8% Eosinophils - 2% Basophils - 1 %
What produces IL-3 and what does it do?
- Produced by activated T cells
- It stimulates growth and differentiation of stem cells in the bone marrow
What produces IL-4 and what does it do?
- Produced by TH2- Helper T cells
- It stimulates growth of B cells and increases the number of TH2-Helper T cells at the site of inflammation
What produces IL-10 and what does it do?
- Produced by macrophages and TH2-Helper T cells
- It is an anti-inflammatory cytokine
- Limits the production of Pro-inflammatory cytokines such as Interferon Gamma, IL-2, IL-3 and TNF-alpha
What produces INF-gamma and what does it do?
- Produced by activated T cells
- Recruits leukocytes and activates phagocytosis
What does Leukotriene B4 do?
- A metabolite of arachidonic acid, it stimulates neutrophil migration to the site of inflammation
Clinical features of Antiphospholipid Antibody Syndrome?
Venous or Arterial Thromboembolic Disease
- Deep venous thrombosis
- Pulmonary Embolism
- Ischemic Stroke/Transient Ischemic Attack
What can happen during pregnancy in a patient Antiphospholipid Antibody Syndrome?
- Unexplained embryonic or fetal loss
- Premature birth due to placental insufficiency or preeclampsia
What are the lab findings in Antiphospholipid Antibody Syndrome?
Lupus Anticoagulant Effect - aPTT prolongation, producing hyper coagulable state due to activation of phospholipid-dependent coagulation pathways. Antiphospholipid antibodies - Anticardiolipin antibody - Anti-beta2-glycoprotein-I antibody
What is Antiphospholipid Antibody Syndrome?
- May be primary or secondary to other autoimmune diseases such as lupus
- Characterized by present of antiphospholipid antibodies in the setting of venous or arterial thromboembolism and/or recurrent pregnancy loss
- Antibodies are present in 10-30% of patients with Lupus but not all exhibit the syndrome
What produces IL-12 and what is its effect?
- Produced by macrophages
- Stimulates differentiation of T-cells into TH1- subset
Hapten
- Less than 6000 D
- Too small to set off an immune response
- 90% of viruses are haptens
Why is it that 95% of the population has CMV and 70% of the population has EMV but they dont get mononucleosis?
- Because the virus is a hapten and it is too small to set up an immune response
- It also lacks variability to set off the immune response
What is the most important factor that determines immunogenicity?
Variability
- It means how different a virus looks to the immune system
- Ex Influenza virus, H1N1 is the variable factor
- With time the virus mutates and gains variability setting off the immune system
Immunogen
- More than 6000 D
- Large enough to set off the immune system
What is an antigen?
- Anything that can be defined, whether it sets off the immune response or not.
- 90% are proteins
- Some are carbs
- The least are lipids (cardiolipin)
Describe the carrier effect and how macrophages process any antigen?
- Phagocytosis
- They ingest the antigen - Phagosome formation
- Lysosomes wrap around the object and release digestive enzymes (acid hydrolases) - Digestion of the antigen
- Presentation
- MHC 2 complexes present foreign antigens to T cells and B cells
- Beta region is used to present the antigeb - Displacement
- Invariant chain is displaced - IL-1 is released
- Macrophages release IL-1 causing fever
What is innate immunity?
- You are born with it
- Consists of neutrophils, macrophages, monocytes, dendritic cells, NK cells and complement
- Resistance occurs through generations
- Response to pathogens is nonscpecific, occurs rapidly and has no memory
- Physical barriers are the skin, epithelial tight junctions, mucus
- Proteins secreted are lysozyme (saliva), the complement, C-reactive protein, defensins
- Toll-like receptors recognize pathogen-associated molecular patterns (PAMPS) such as LPS (gram - bacteria), flagellin (bacteria) and nucleic acids (viruses)
What is acquired immunity?
- You acquire it
- Either via infection or via vaccination
- Consists of T cells, B cells, circulating antibodies
- Can have variation due to V(D)J recombination during lymphocyte development
- Highly specific, refined over time, develops over long periods of time, memory response is faster and more robust
- No physical barriers
- Proteins secreted are immunoglobulins
- Consists of memory cells: activated B and T cells subsequent exposure to a previously encountered antigen leads to a stronger and quicker immune response
Live attenuated vaccine
- Vaccine is denatured so that virus can not produce infection
- You keep the variability in order to get an antibody response
- 1-3 % chance of people get infection
- 10% of immunocompromised get infection
- Do not give to immunotcompromised
Killed inactive vaccine
- Virus is killed so it does not cause infection
- Used for deadly viruses which you might die from
- Rabies, polio, influenza
Conjugated vacccine
- For bacteria
- Means a piece of the bacteria (hapten) is attached to a immunogen
- That way the immune system responds to the immunogen without producing infection
- Vaccine may fail if hapten falls off immunogen or if the patient has anergy (already sick)
- This is why vaccines are given on the same day
- DPT (Diphtheria, Pertussis, Tetanus)
How do you know if a vaccine is working?
Check the IgG levels (memory)
Toxoid vaccine
- For bacteria that produce a toxin
- The toxin is what will kill the patient, not the bacteria
- Tetanus toxin, botulinum toxin