Path 3 Flashcards
Toll-like receptors
MO & dendritic cells Recognize patterns (PAMPs) - CD14 on MO recognizes LPS --> upregulates NK-kB --> production of mutliple immune mediators
PGI, D, E2
Vasodilation at arteriole and inc permeability at post-capillary venule
PGE2
Fever & pain
LTB4
Attracts and activates neutrophils (IL-8, and C3b also)
LTC, D, E4
Vasoconstriction, bronchospasm, inc vascular permeability - contract smooth muscle
Second phase of mast cell response
LEUKOTRIENES
Classical complement pathway
GM makes classic cars - IgG or IgM bound to Ag –> C1 binds and activates
Alternative complement pathway
Microbial products directly activate complement
Mannose-binding Lectin pathway
MBL binds to mannose on microorganisms –> activation
C5a
Neutrophil chemotaxis
C3b
Opsonization for phagocytosis
Hageman Factor (XII)
Important role in DIC
- coagulation, fibrinolytic systems, complement, kinin
Factors mediating vasodilation/redness
Histamine
PGs
Bradykinin
Fever mechanism
LPS –> MO –> IL-1 & TNF –> COX in hypothalamus –> PGE2 –> inc temp set point
Neutrophil arrival
Margination –> Rolling –> Adhesion –> Transmigration & Chemotaxis –> Phagocytosis –> Destruction
Margination
vasodilation slows BF in post-capillary venule –> periphery of BV
Rolling
P-selectin - Weibel-Palade bodies (Histamine)
E-selectin - TNF & IL-1
Bind sialyl Lewis X on leukocytes
Adhesion
Endothelium - ICAM & VCAM via TNF, IL-1
Leukocytes - integrins via C5a, LTB4
Leukocyte adhesion deficiency
AR defect in integrins (CD18)
- delayed umbilical cord separation
- recurrent bacterial infection W/O pus
- Inc circulating neutrophils
Neutrophil phagocytosis mech
Enhanced by opsonins - IgG & C3b
Chediak-Higashi
AR defect in microtubules –> impaired phagolysosome formation
- inc pyogenic infections
- neutropenia
- GIANT GRANULES IN LEUKOCYTES
- ALBINISM
MPO deficiency
Defective conversion from H2O2 –> HOCl
NBT normal
Inc CANDIDA infections
MO fxns
Resolution/Healing - IL-10, TGF-B
Continued acute inflammation - IL-8 = more neutrophils
Abscess - wall of acute inflammation w/ fibrosis
Chronic inflammation - present Ag to CD4 –> chronic inflammation
CD4+ activation
EXTRAcellular Ag - phagocytosed –> MHC II
B7 on APC binds CD28 (28/7 = 4)
TH1 –> IL-2 (CD8) & IFN-y (MO)
TH2 –> IL-4 (B-cells from IgG –> IgE) & IL-5 (eosinophils & IgA) & IL-10 (inhibits TH1)
CD8+
INTRAcellular Ag - ALL nucleated cells
IL-2 from CD4 TH1
Perforin & granzymes –> APOPTOSIS
FasL binds Fas –> APOPTOSIS
B-cell activation
- Ag bind to IgM or IgD –> plasma cells
2. B-cell Ag to CD4 on MHC II + CD40/CD40L on Th cells –> IL-4, 5 –> class switch and maturation
Key characteristic of granuloma
Epithelioid histiocytes
Can see giants cells and rim of lymphocytes
MO present Ag on MHC II –> IL-12 –> TH1 –> IFN-y –> converts MO to epithelioid histiocytes
Non-caseating granuloma
LACK central necrosis
- Foreign material - breast implant
- Sarcoid
- Beryllium
- Crohn
- Cat scratch - “stellate shaped”
Caseating granuloma
Central necrosis
- TB - AFB stain
- Fungal infections - GMS stain
DiGeorge
Failure of 3rd & 4th pouch
22q11 deletion
No thymus, no T-cells, HypOCa –> tetany, cardiac & facial anomalies
SCID
- cytokine receptor defects - no B or T cell maturation
- ADA - buildup of de-oxyadenosine os toxic to lymphocytes
- MHC II deficiency - CD4 not activated = defective B & T cells
Fungal, viral, bacterial, protozoal, opportunisitc
X-linked Agammaglobulinemia
TK deficiency –> B-cells can’t mature to plasma cells = no Ig
- Bacterial - no opsonin (IgG)
- Enterovirus - mucosal GI (IgA)
- Giardia
Most common Ig deficiency
IgA deficiency
Celiac Disease
Hyper IgM syndrome
Mutated CD40 (B cells) or CD40L (T cells)
Low IgA - mucosal
Low IgG - pus infections d/t poor opsonization
Low IgE
Wiskott-Aldrich
- Thrombocytopenia
- Ezcema
- Recurrent Infection
Most common injury/cause of death in SLE
Diffuse proliferative glomerulonephritis
Libman-Sacks endocarditis
SLE - sterile deposits in BOTH sides of heart valve, esp mitral
Drug-Induced lupus
Anti-Histone Abs
- Hydralazine
- Procainamide
- Isoniazid
Anti-phospholipid syndrome
Subset of SLE
- Cardiolipin - False + syphilis test
- Lupus anti-coagulant - falsel elevated PTT = hypercoagulable state –> DVT, recurrent miscarriages, Budd-chiari
Sjogren Syndrome
Type IV HS
Dry eyes, mouth, dental carries
Anti-Ribonucleoprotein abs
Assoc w/ RA
Disease assoc w/ inc risk of B-cell (mantle zone) lymphoma
Sjorgen syndrome
- U/L enlargement of parotid
Can’t chew a cracker, dirt in my eyes
Sjogren syndrome
Anti-DNA topoisomerase I Abs
Diffuse scleroderma
Anti-Centromere Abs
Localized scleroderma (CREST)
Anti-U1 Ribonucleoprotein Abs
Mixed CT disease
Granulation tissue
1st phase of repair
Fibroblasts - type III collagen
Capillaries - nutrients
Myofibroblasts - contract wound
Scar formation
Type III collagen replaced w/ type I
- collagenase requires ZINC
Keloid
Type III collagen
Hypertrophic scar collagen type
Type I