[1] Inflammation Flashcards
Neutrophils are attracted to these chemical attractants
IL8
C5a
LTB4
Bacterial components
Where do neutrophils migrate to exert their action?
Post-capillary Venule
Disease characterized by impairment in protein trafficking
Chediak-Higashi Syndrome
Clinical Features of Chediak-Higashi Syndrome
- Increased risk of pyogenic infections
- Neutropenia
- Giant granules in leukocytes
- Defective primary hemostasis
- Albinism
- Peripheral Neuropathy
Most effective mechanism of killing phagocytosed materials?
O2-Dependent Killing Mechanism
What converts Oxygen to Superoxide
NADPH
Also called oxidative burst
What converts Superoxide to Hydrogen Peroxide?
Superoxide Dismutase
What converts Hydrogen Peroxide to HOCl (Bleach)?
Myeloperoxidase
What is defective in Chronic Granulomatous Disease
NAPDH Oxidase Defect
Patients with CGD have granuloma formation with these kinds of organisms
How come only these organisms can cause infections?
Catalase-positive
Most bacteria produce hydrogen peroxide, which can be converted to HOCl, but those that produce catalase breakdown H2O2, therefore disrupting the pathway
Test used to screen for CGD
How?
Nitroblue Tetrazolium Test
Turns blue if NADPH oxidase can convert O2 to O2-
Patients with MPO deficiency are usually asymptomatic but do have an increased risk for these infections
Candida Infections
Neutrophils disappear after how many hours via what mechanism?
24 hours via apoptosis
What leukocyte predominates after the neutrophil phase?
Macrophage
Macrophages manage the next step of the acute inflammatory process of resolution and healing by secreting?
Resolution and Healing: IL-10 and TGF-B (Anti-inflammatory)
How do macrophages recruit additional neutrophils?
Secrete IL-8
4 Possible Endpoints of the Acute Inflammatory Process
- Resolution and Healing
- Continued Acute Inflammation
- Abscess Formation
- Chronic Inflammation
Chronic inflammation is characterized by?
Lymphocytes and plasma cells in tissue
T Cells are produced in?
Bone Marrow
TCR Complexes can only recognize antigen when presented by?
MHC
CD4 and CD8 T-Cells recognize which MHC Class
CD4 :: MHC II
CD8 :: MHC I
Immature B Cells are produced in?
Bone Marrow
Function of IL-4
Class Switching of IgG -> IgE
Function of IL-5
- Eosinophil chemotaxis and activation
- Maturation of B cells to plasma cells
- Class switching to IgA
Function of IL-10
Inhibits TH1 Phenotype
How are CD8 TCells Activated?
- Intracellular antigen is presented to MHC I
- IL-2 from CD4 TH1 Cells provide a 2nd activation signal
- Cytotoxic T-Cells activated for killing
Key enzyme that mediates apoptosis?
Caspases
How are B-Cells Activated?
- Antigen binding by surface IgM or IgD
- Becomes an IgM or IgD secreting Plasma Cell
or
- Antigen presentation to CD4 Helper T Cell via MHC II
- CD40 receptor on B-Cells bind CD40L on Helper T Cell providing 2nd activation signal (Secretes IL-4,IL-5)
What is the defining characteristic of a granuloma?
Epithelioid histiocytes (macrophages with abundant pink cytoplasm)
How can you differentiate caseating from non-caseating granulomas?
Central Necrosis
Caseating granulomas are characteristic of these diseases
TB and Fungal Infections
Steps involved in Granuloma Formation
- Macrophages present antigen via MHC II to CD4 Helper T Cells
- Macrophages secrete IL-12, inducing CD4 to differentiate into TH1 Subtype
- TH1 Cells secrete IFN-Y which converts macrophages to epitheliod histiocytes
Function: IL-12
Induce CD4 to differentiate into TH1
What do helper T Cells secrete to convert macrophages to granulomas?
IFN-Y
DiGeorge Syndrome is a developmental failure of?
This is due to a deletion of which chromosome?
3rd and 4th Pharyngeal Pouch
22q11 microdeletion
Presentation of DiGeorge Syndrome
- T-Cell Deficiency (Lack of Thymus)
- Hypocalcemia (Lack of Parathyroids)
- Abnormalities of heart, great vessels, and face
Etiologies of SCID
- Cytokine Receptor Defects
- Adenosine deaminase deficiency (Adenosine and Adenosine oxide are toxic to lymphocytes)
- MHC Class II Deficiency
Treatment for SCID
- Sterile Isolation
2. Stem Cell Transplant
X-Linked Agammaglobulinemia is a defect in?
Complete lack of immunoglobulin
Due to disordered B-cell maturation
X-Linked Agammaglobulinemia is caused by which mutated gene?
Mutated Tyrosine Kinase
These infections are common in patients with X-Linked Agammaglobulinemia
Bacterial
Enterovirus
Giardia infections
(Mucosal infections: IgA deficiency)
How come patients with X-linked Agammaglobulinemia only present with symptoms after 6 months of life?
They have their mother’s immunoglobulins (IgA) through breast milk
What is the most common Ig deficiency?
IgA
Which GI disease is commonly associated with IgA deficiency?
Celiac Disease
What is the cause of Hyper IgM Syndrome?
Mutation of the CD40L or CD40 Receptor (Cannot use the alternate pathway of B-Cell Activation)
Which Immunoglobulins would be low in patients with HyperIgM Syndrome?
IgA
IgG
IgE
Triad of Wiskott-Aldrich Syndrome
- Thrombocytopenia
- Eczema
- Recurrent infections
C5-C9 deficiencies would have an increased risk for what kind of infections?
Neisseria
Autoimmune diseases are caused by a loss of this defense mechanism
Self-tolerance
SLE causes systemic damage via which Hypersensitivity Reactions?
Type II (Cytotoxic) Type III (Antigen-Antibody Complexes)
This is the most common type of renal damage in patients with SLE
Diffuse proliferative glomerulonephritis
What is unique about Libman-Sacks endocarditis?
Presence of vegetation on both sides of the heart valves
What is characteristic of drug-induced SLE?
Antihistone Antibody
These drugs are common causes of drug-induced SLE?
Hydralazine
Procainamide
Isoniazid
Which antibodies are associated with Antiphospholipid Syndrome?
Anticardiolipin
Lupus Anticoagulant
Anticardiolipin interferes with this test
Leads to a false-positive syphilis test
Lupus Anticoagulant interferes with this diagnostic test
Elevated PT/PTT
Treatment for APAS
Lifelong anticoagulation
Sjogren Syndrome is associated with destruction of these glands
Lacrimal
Salivary
Classic antibody test for Sjogren Syndrome
ANA
Anti-ribonucleoprotein Antibodies (Anti-SS-A and Anti-SS-B)
Patients with Sjogren syndrome usually present with bilateral parotid gland enlargement. What is the significance of a unilateral enlargement of a parotid gland late in the disease course?
The patient has possibly developed a B-cell Lymphoma
Scleroderma is characterized by these antibodies
Anti-DNA Topoisomerase I Antibody (Scl-70)
Classic Presentation of Crest Syndrome
Calcinosis/Anti-Centromere Antibody Raynaud Phenonemon Esophageal Dysmotility Sclerodactyly Telangectasias of Skin
Where are the stem cells located in the small and large bowels?
Mucosal Crypts
Where are the stem cells located in the skin?
Basal Layer
Where are the stem cells located in the bone marrow?
Hematopoietic Stem Cells
Where are the stem cells located in the lung?
Type II Pneumocytes
What is the marker for hematopoietic stem cells?
CD34
Which tissues in the body have poor/no regenerative potential?
Skeletal Muscle
Neurons
Cardiac Muscle
What are the components of granulation tissue?
- Fibroblasts
- Capillaries
- Myofibroblasts
What do fibroblasts do in the initial phase of repair?
Deposit Type III Collagen
When granulation tissue scars, this type of collagen is replaced with what type of collagen?
Type III -> Type I Collagen
Type I Collagen is commonly seen in?
Bone
[b-ONE]
Type II Collagen is commonly seen in?
Cartilage
[Car-TWO-lage]
Type III Collagen is commonly seen in?
Blood vessels, granulation tissue, embryonic tissue
[Seen in tissues that are able to stretch. s-THREE-tch]
Type IV Collagen is commonly seen in?
Basement Membrane
During repair, collagenase removes Type III collagen, but requires what as a co-factor?
Zinc
[Function]
FGF
Angiogenesis
Skeletal Development
[Function]
VEGF
Angiogenesis
[Function]
TGF-A
Epithelial and Fibroblast Growth Factor
[Function]
TGF-B
Inhibits Inflammation
Fibroblast Growth Factor
[Function]
PDGF
Endothelium, Smooth Muscle, Fibroblast Growth Factor
Differentiate healing via primary versus secondary intention
Primary: Wound edges brought together; minimizes scar formation
Secondary: Edges are not approximated, granulation tissue fills in the defect