Immunology Flashcards by John Nathanson

Why don’t anti-hep C envelope antibodies confer lasting immunity?

Because there is a huge amount of antigenic variation amongst hep c envelope proteins. They are prone to mutation and there is no 3-5 exonuclease activity. Also multiple subspecies can infect at once. This is why there is no vaccine for hep c

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Why do we give Rh- mothers Anti RhD IgG antibodies if their baby is Rh positive?

Because they will cross the placenta and neutralize a number of rh+ RBCs. This will prevent a maternal immune response. This doesn’t kill the baby because the amount of IgG adminstered is so much less than if there were an actual immune response.

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How is MHC I presented?

Antigen loaded in RAR, taken to membrane via TAP

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How is MHC II presented?

Antigen is loaded following the release of the invariant chain in acidified lysosome

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Interferon alpha and beta?

Produced as a defense against viral infections. Released by virally infected cells to prime cells around them should they become infected. Primed cells respond to viral dna by degrading viral mRNA and inhibiting protein synthesis. Then apoptosis occurs

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What cells produce interferon gamma?

NK cells and macrophages to increase MHC class II, increase TH1 cells, and cause killing of viral cells

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What is secreted by TH1 Cells?

IFN gamma, Il2

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What is secreted by TH2 cells?

IL4 (ige and igg), Il5 (iga and eosinophil activation), Il10 (stops TH1)

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Tryptase

Released by mast cells in addition ot histamine during anaphylaxis

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CD19+ Cells

Only B cells that remain in Brutons X-linked agammaglobulinemia.

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Marker of NK cells?

CD16 and CD56

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How to tell if a patient has combined immunodeficiency?

They have bacterial, viral and fungal infections

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Cells involved in type IV HSR

Macrophages, CD4, CD8, NK cells

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How does fas cause apoptosis

FAS binds FASL and creates FADD binding site. Which activates caspases

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How to toddlers present with hepatitis A

Usually an anicteric viral illness

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Hemolytic disease of the newborn

If mom has O blood, and baby as A, B, AB, mom has anti a anti B IgG. Cross placenta and cause hemolysis. If mom has a or b, she has IgM antibodies which do not cross

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What do sarcoid granulomas produce?

1,25 OH D and ACE

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Lysozyme

Oxygen independent killing in neutrophils. Hydrolyzes peptidoglycan cell walls. Found in tears and saliva.

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Why can neisseria infections recur?

Have high degree of antigenic variation.

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CD14

Is a marker of monocytes and macrophages

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Leukocyte adhesion deficiency

Decrease in CD18+, which is a neutrophil integrin. No pus, delayed separation of the umbilical cord, poor wound healing.

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Acute hemolytic transfusion reaction

Causes fever, chills, chest pain, back pain, hemoglobinuria. Is a type II HSR against Blood cells.

Acute nonhemolytic transfusion reaction has fever and chills. Due to type II HSR against foreign proteins.

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Vaccines conjugated to toxoid

Pneumo, neisseria, haemophilis

GVHD Symptoms

DIARRHEA, rash, hepatosplenomegaly (usually after bone marrow or liver transplant). T cell mediated

Chronic granulomatous disease

Infection with catalase positive organisms, recurrent bacterial infections with lymphadenitis. Negative nitrozolium blue test

How to prevent neonatal tetanus

Vaccinate the mom with toxoid

What causes ataxia in ATM?

Cerebellar atrophy All due to NHEJ

Chronic allograft rejection

Happens months to years after transplant, causes bronchiolitis obliterans in lungs, atherosclerosis in heart, obliterative vascular thickening and tubular atrophy in kidney.

Acute kidney allograft rejection

Marked by vascular fibrinoid necrosis with neutrophils

IgA deficiency anaphylaxis?

Because often have IgG anti IgA! Transfusion with anything with IgA products will cause anaphylaxis

What do eosinophils do

They are produced in response to IL5. Bind to IgE, release major basic protein and ROS to destroy helminths. they are antibody dependent cell mediated killing

ABPA occurs where and causes what

Occurs in steroid dependent asthmatics. Can cause bronchiectasis

Varices come from..

Left gastric artery (portal) -> esophageal (systemic Hemorrhoids - superior rectal ->middle and inferior rectals (systemic) Caput medusae -- paraumbilical veins --> superficial epigastric veins (systemic)

Isolated SYSTOLIC ONLY hypertension

Comes from reduced compliance in aorta and its branches.

Where do ureters gain access to pelvis

At bifurcation of common iliac. Ureters sit anterolateral to internal iliac.

First line for gout?

Indomethacin/colchicine GLucocorticoids if renal failure and can't tolerate NSAIDS or colchicine.

Most toxic effect of amphotericin?

Nephrotoxicity. Can also cause hypokalemia and hypomagnesemia

Omalizumab

Anti IgE MAB for asthma that won't respond to treatment

Disseminated gonorrhea symptoms?

Arthritis, dermatitis, tenosynovitis

Which immune cells are responsible for cutaneous candidiasis? Which are responsible for preventing dissemination?

Cutaneous candidiasis prevented by t-cells (thrush, cutaneous, vulvovaginitis) Dissemination prevented by neutrophils

What are the abnormal cells in EBV?

They are reactive T-lymphocytes,

Antiphospholipid syndrome

Anticardiolipin/b2glycoprotein. PTT is increased but coagulation occurs in vivo

Acute serum sickness

Type III HSR that develops 5-10 days after infusion of a drug. Causes fever, pruritic rash, fibrinoid necrosis

Urushiol

The oil in poison ivy/poison oak/sumac that causes a type IV HSR. CD8 cells destroy keratinocytes expressing hapenated proteins

IL2

T-cell maturation, but also activation of NK cells and B cell growth

Where does isotype switching occur?

In the follicle of lymph nodes (germinal centers)

VDJ vs VJ recomination Where does it occur?

VDJ- heavy chains VJ-light chains Occurs in the bone marrow for B cells.

NK cells killing technique

Secretes perforins and granzymes which induce apoptosis.

NK Cells advantage over cell-mediated immunity

Don't require a thymus, don't require MHC class I (so can kill tumor cells that downregulate it), activated by interferon gamma and il2. Aren't antigen specific

E. coli antigens that cause neonatal sepsis uti septic shock

Neonatal sepsis caused by capsule UTI caused by p-fimbriae septic shock caused by lipid a (activation of IL1, IL6, and TNF alpha)

Henoch-schonlein purpura symptoms

After viral infeciton in kids, causes proteinuria/hematuria, abdominal pain, palpable purpura.

sIGA

Iga dimer linked by J chain, found in tears, saliva, breast milk (colostrum)

What type of receptor is the interferon gamma receptor

JAK-STAT receptor

Acute heart rejection

Weeks to months, caused by T-cells. Causes vasculitis of graft vessels with dense interstitial lymphocytic infiltrate.

How does flu vaccine cause protection

Creates antibodies against hemagglutinin