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
Fever
- One degree above normal body temperature
- Due to IL-1 production
- Raises HR by about 10 BPM for every 1 degree increase
- Allows immune cells to circulate faster
- Causes secretion of IgA in mucosal surfaces
- Causes discomfort after about 101 degrees, treat if above
- Fever by itself cannot tell you cause of infection
Macrophages in the brain
Microglia
Macrophages in the lungs
Alveolar macrophages
- Phagocytose foreign materials, release cytokines and alveolar proteases
Macrophages in the liver
Kupffer cells
Macrophages in the spleen
Reticuloendothelial cells
Macrophages in the lymph nodes
Dendritic cells
Macrophages in the bone
Osteoclasts
Macrophages in the kidneys
Mesangial cells
Macrophages in the intestines
M-cells in peyers patches
Macrophages in the skin
Langherhans cells
Macrophages in the blood
Monocytes
- Emerge put of the bone marrow with CD-4 marker
- When they enter tissue, graduate to CD-14 marker
- Transformation allowed via interferon gamma produced by T-cells
Macrophages in connective tissue
- Epitheloid cells
- Giant cells
- Histiocytes
Name the 8 most common T-cell immunodeficiencies
- DiGeorge Syndrome (Thymic Aplasia)
- Chronic mucocutaneous candidiasis
- Steroids
- Cyclosporine
- Hairy cell leukemia
- SCID
- Wiscott-Aldridge syndrome
- HIV
What is DiGeorge Syndrome?
- Third pharyngeal pouch is missing
- Missing thymus and imferior thyroids
- Hypoparathyroidism
- Has hypocalcemia, morelikely to depolarize
- Associated with chromosome 22
- Same chromosome as CML, Neurofibromatosis and Ewing Sarcoma
What 4 syndromes are associated with chromosome 22?
- Digeorge
- CML 9-22
- Neurofibromatosis 17-22
- Ewing sarcoma 11-22
What is Chronic Mucocutaneous Candidiasis?
- T cell defect at sub-molecular level
- T- cells can fight everything except candida
- Candida infections on skin and mucous membranes
- Chronic fatigue syndrome
- Feel warned down, spit, pee and bowel had curdy white dischrage
- Treat with miconazole
What are the anti-inflammatory actions and the physiologic actions of steroids?
Anti-inflammatory actions - Kills T cells and eosinophils - Inhibit macrophage migration - Stabilize mast cell membranes - Stabilize endothelium - Inhibit phospholipase A Physiologic actions - Proteolysis - Gluconeogenesis - Upregulates all receptors during stress
Prednisone
- Main oral steroid
Hydrocortisone
- Main topical or injectable form
Methylprednisolone
- Main IV form
Betamethasone and Beclomethasone
- Enhances surfactant production in the fetus
Triamcinolone
- Main inhaled form
- For asthma maintenance
Fluticasone and Mometasone
- Main spray form for nasal allergies
Fludrocortisone
- Main replacement for aldosterone in patients with adrenal insufficiency
Danazole
- Main treatment for endometriosis
- Most adrogenic
- Creates imbalance between androgens and estrogens
- Causes endometrial tissue atrophy
Cypropterone
- Blocks DHT receptors
- For prostate cancer
Megesterol
- Used to increase appetite in cancer patients
Dexamethasone
- Best CNS penetration
- Now the DOC for increased surfactant production in premature newborns
- Crosses the placenta faster
What is cyclosporine, what are its side effects and what is used now instead?
- Prolongs longevity of transplanted organs
- Inhibits calcineurin
- Calcinuerin is needed for interleukin production
- Side effects are gingival hyperplasia, hirsutism and renal failure at PCT
- Tacrolimus is used now with less side effects
Hairy cell leukemia
- Most common B cell leukemia
- Cell have hairy cell membranes projections or fried egg appearance
- Tartrate resistant acid phosphatase (TRAP) is the marker
What is more common, B or T lymphocytes?
Which is more likely?
You have 98 B lymphocytes for every 2 T lymphocytes
Therefore it is more common to be a B cell leukemia
Hoever the incidence of hairy Cell leukemia in T form is 25% of the general population, so its is more likely
How do T cell lymphomas present cutaneously and in the blood?
- Mycosis fungoides in the skin, looks like fungus
- Sezary syndrome in the blood
- T cells have characteristic indented cell membrane
SCID
- Autosomal recessive, 25% chance of getting
- Adenosine deaminase deficiency
- DNA synthesis is disrupted
- Affects all rapidly dividing cells
- Affects T-cells and B-cells
- Diagnosed in fetus via chorionic villous sampling at 12 weeks
- Bone marrow transplant done in newborn
Wiscott-Aldridge Syndrome
- Involves T cell interaction with B cells
- X-linked recessive
- Carried by females, males get it
- Fair skinned, eczema, thrombocytopenia
- Increased incidence of lymphoma (10-12%)
- Normal IgA and IgE
- Problem with isotype switching back to IgM