Immunology Flashcards
Immune response against giardia
IgA and Th cells. Eosinophils more responsible for helminths vs the trophozoite giardia
Sirolimus MOA
Inhibits mTOR pathway, disupting IL-2 signal transduction, preventing G1 to S progression and lymphcyte proliferation
Rituximab MOA
Chimeric antibody that targets CD20, depleting B cells.
Function of Th2 cells
Promote humoral immune response by secreting IL-4 and IL-5, which activate B cells.
IL-1
produced by macrophages. Activates Th0 cells, promoting them to differentiate into Th1 and Th2. Endogenous pyrogen
IL-2
Produced by Th1 cells. Stimulates development of CD4+, CD8+, and B cells.
IL-3
Produced by Th cells. Stimulates growth and differentiation of bone marrow stem cells
IL-10
Produced by Th2 cells. helps regulate balance between Th1 and Th2 populations. Inhibits synthesis of interferon gamma, leading to decrease in Th1s.
IL-12
Synthesized by macrophages. Stimulates Th1 growth and evelopemnt.
IL-4
Produced by Th2 cells. Facilitates growth of B cells and Th2 cells. Stimulates antibody isotype switching.
Type I interferons
Interferon alpha and beta. Made by most cells when infected by virus. Signal infected and neighboring cells to ahlt protein synthesis if the cell is infected with dsRNA.
Type II interferons
Interferon gamma. Produced by T cells and NK cells. Promotes Th1 differentiation, increases MHC class II expression, increases intracellular killing by macrophages.
Hyper-IgM syndrome
Inability of B cells to isotype switch. Presents with lymphod hyperplasia and recurrent sinopulmonary infections.
Transplant rejection types
Hyperacute: occurs in minutes to hours due to preformed antibodies against graft in patient’s blood. Results in gross mottling and cyanosis and thrombotic occlusion
Acute: occurs in first 6 mos due to induction of humoral/cellular activation of naive immune cells against donor antigens. Hmoral rejection results in CD4 deposition, nuetrophils, and neccrotizing vasculitis. Cellular response results in lymphocytic infiltratates and endotheliitis
Chronic: occurs in months to years due to chronic low grade immune response refractory to immunosuppressants; results in vascular wall thickeining/luminal narrowing and interstitial fibrosis and parenchyma atrophy
Langhans giant cell
T-cell activated macrophages with multiple nuclei organized peripherally in a horseshoe shape. Nonspecific finding in granulomatous conditions.
IL-8
Released by macrophages. Chemotactic for neutrophils. Induces phagocytosis in neutrophils once they have arrived
C3a
Anaphylotoxic (triggers histamine release from mast cells). Recruits and activates eosinophils and basophils, not neutrophils.
C4a
Anaphylotoxic (tirggers histamine release from mast cells)
C5a
Anaphyotoxic (triggers histamine release from mast cells). Recruits and activates neutrophils, monocytes, eosinophils, basophils
Natural killer cells
Destroy cells with decreased or absent MHC class I on surface, such as in virus-infected cells and tumor cells.
CD14
marker of monocyte-macrophage cell lineage
IL-5
Produced by Th2 and mast cells. Stimulates eosinophil prolferation and activation during parasitic infection
Immune defense against parasites
- parasite invades mucosa or blood
- IgG and IgE coat parasite and bind eosinophil via Fc receptor
- eosinophil degranulates and releases major basic protein that damages the parasite (antibody-dependent cell-mediated cytotoxicity)
T cell maturation
- subcapsular zone: double negative precursor
- cortex: double positive. Undergo positive selection to ensure have affinity for self MHC
- medulla: single positive for either CD4 or CD8. Undergo negative selection to ensure don’t have excess affinity for self antigens and MHC
Features of sarcoidosis: epi, clinical, imaging, labs, path
Epi: young african americans
Clinical: cough, dysphea, chest pain
Imaging: bilateral hilar adenopathy and pulmonary reticular infiltrates
Labs: high calcium, high ACE
Pathology: noncaseating granulomas
HBeAg and anti-HBeAg
HBeAg in serum is a marker of viral replication and high infectivity. Anti-HBeAg in the srum indicates cessation of active viral replication and low infectivity.
leukocyte adhesion deficiency
Pathophys: failure to express CD18 integrin, leading to disordered leukocyte migration. Defects in several proteins including LFA-1.
Presentation:: delayed separation of umbilical cord stump. Omphalitis. Recurrent bacterial infections and impaired wound healing. Perirectal abscess a common finding.
Labs: Elevated white count.
chronic granulomatous disease
Pathophys: phagocytes can’t make ROS
Presentation: opportunistic infections
Labs: Neutropenia
Diagnosis: neg nitroblue tetrazolium dye reduction test
Thymoma presentation
Associated with paraneoplastic syndromes: myasthenia gravis, pure RBC aplasia, hypogammaglobulinemia
Endotoxin of N meningitidis
Lipooligosaccharide - analagous to LPS found in most gram negs
Endogenous pyrogens
IL-1, IL-6, TNF-alpha
Treatment of Guillan Barre
plasmapheresis and immunoglobulin
hapten
molecule that an’t elicit immune response on own because can’t activate Th cells, but can elicit response when binds to a protein
Henoch-Schonlein purpora
vasculitis. Presents with palpable pruritic lesions of butt and legs, arthralgias, fever, malaise, episodic abdominal pain. Can cause renal failure with mesangial IgA deposition. C3 normal.
Complication of juvenile arthritis
Uveitis that can lead to blindness
Job syndrome
failure of Th cells to make interferon gamma. Presents with recurrent staph infections, eczema, high IgE.
Presentation of Kaposi’s sarcoma
Cutaneous lesions. Can also affect lungs, GI tract, biliary tree. If GI involvement, can get hematochezia, hematemesis, melena
