What part of the lymph node do T cells mature? B cells?
- T cells in the cortex
- B cells in the follicles (undergo somatic hypermutation)
What zone lets T cells and B cells escape into lymph node?
HEV zones (high endothelial venules)
What enzyme assists with somatic hypermutation?
AID (activation induced deaminase)
What are the 2 OTC antihistamines that cause sedation and drying secretions?
- Diphenhydramine
- Chlorpheniramine
What are the 3 OTC antihistamines that don’t cause drowsiness?
- Cetirizine
- fexofenadine
- Loratadine
What are zileuton, zafirlukast, and montelukast?
leukotriene modifiers
What enzyme converts histidine to histamine? what type of cells have it?
- L-histidine decarboxylase
- mast cells and basophils
Where are H3 and H4 receptors found?
-H3: histaminergic nerve terminals
-H4: eosinophils, DCs, T cells, neutrophils
No clinically useful agents yet available
What enzyme releases Arachidonic Acid from phospholipid cell membrane?
phospholipase A2
What is the pathway to causing a fever?
inflammation activates IL-1 which activates PGE2
- goes to hypothalamus and causes fever
- enhanced cytokine production: IL-1, IL-6, IFN, TNF
What is the mechanism of hypersensitivity like reaction to aspirin?
-blockage of COX shifts AA utilization to lipoxygenase pathway resulting in increased leukotriene production
What enzyme converts Leukotriene A4 to LTB4? to LTC4/D4/E4?
- to LTB4 by LTA hydrolase
- to LTC4/D4/E4 by glutathione S-transferase
Which leukotriene is mostly made by PMNs? mast cells and basophils?
- PMNs= LTB4
- mast cells and basophils= peptido-leukotrienes
What are leukotriene inhibitors/ modifiers used to treat?
- bronchial asthma (chronic > acute)
- Zileuton (inhibits 5-lipoxygenase to prevent LTB4)
- Zafirlukast and Montelukast (antagonist to LTD4 receptor and Cys LTR1)
What are the 2 classes of steroids produced by the adrenal cortex?
- corticosteroids (glucocorticoids and mineralocorticoids)
- androgens
What can result from abrupt cessation of prolonged, high dose glucocorticoid therapy?
-adrenal insufficiency (can be fatal)
What enzyme does Sirolimus inhibit?
- FKBP; blocks progression from G1 to S phase
- used in combination therapy for organ transplant rejection
- blocks mTOR pathway
What enzyme does Mycophenolate Mofetil block?
- inosine monophosphate dehydrogenase (IMPDH)
- important enzyme in de novo pathway of guanine nucleotide synthesis (B and T cells are highly dependent on this pathway for cell proliferation)
What is anti-thymocyte globulin (ATG) used for?
- binds to thymocytes in circulation resulting in lymphopenia and impaired T cell immune responses
- toxicity: serum sickness and nephritis
What is muromonab-CD3 used for?
- prevent acute rejection of kidney, liver, and heart transplants
- causes T cell receptor to be internalized to prevent further antigen recognition
What type of drugs are Daclizumab and Basiliximab? Use?
- anti- IL2 receptor (anti CD25) antibodies
- used in organ transplantation
Where are palisading macrophages found?
rheumatoid nodules (around central fibrinoid necrosis)
Patients with Sjogren syndrome are more likely to develop which malignancy?
-marginal zone lymphoma
What is normal value of CD4? below what increases risk for opportunistic infections? below what number considered advanced HIV?
- normally 500-1200
- below 500 at risk for opportunistic infections
- below 200 considered advanced HIV disease
