Inflammation Flashcards
3 types of inflammation and key differences
acute: neutrophil-mediated, regeneration of normal tissue architecture
chronic: mononuclear cell-mediated, tissue cell death and architecture destruction, repair includes new blood vessels/connective tissue (scars)
granulomatous: mediated by specialized macrophages, circumscribed chronic inflammation, when causative agent can’t be removed so it is sequestered instead
granulomatous inflammation
mediated by specialized macrophages, circumscribed chronic inflammation, when causative agent can’t be removed so it is sequestered instead
describe what occurs during acute inflammation
macrophages release histamine, serotonin —> vascular dilation, plasma leakage to interstitium
later - neutrophil emigration (diapedesis) and phagocytosis, recruitment of macrophages which clean up neutrophil lysis
resolution: macrophages transition to anti-inflammatory (IL-10, TGF-b) and leave the field
what occurs during “red hepatization” of the lung?
due to inflammation of the lung from lobar pneumonia
lung has heavy and dark red appearance - neutrophils have filled in the alveolar spaces
what typically occurs in viral pneumonia presenting with pulmonary inflammation?
mononuclear inflammatory infiltrate, characteristically seen in interstitium
upon activation, mast cells release effector molecules in a time-dependent fashion. describe this (and what is released)
within second: degranulation - histamines, TNF-a, amines
within minutes: eicosanoids - luekotrienes and prostaglandins
within hours: cytokines, chemokines, growth factors
result: vasodilation, vascular leakage, inflammatory cel activation
contrast histamine release from mast cells to cytokines and eicosanoiods release
histamine: already present in granules, released in response to injury/immune reaction/C3a and C5a complement (anaphylatoxins)
cytokines and eicosanoids: synthesized de novo, secreted in response to viruses/bacterial LPS/TLR activation/immune reaction
_____ cytokine mediates an increase in endothelial transcytosis during microvascular leakage in inflammation
VEGF: vascular endothelial growth factor
T/F: histamine- mediated vascular leakage follows a stereotypic time course
TRUE: histamine mediated leakage is gated
what is the major mechanism of inter-endothelial leakage during inflammation, induced by histamine
endothelial shape change, induced by histamine
results in opening of inter-endothelial junctions, allowing for leakage
how is inflammatory edema different than general edema
inflammatory edema has fluid that is localized and has a high protein concentration (exudate)
general edema occurs form imbalance of hydrostatic and osmotic pressures
stasis
as fluid leaves vascular use, blood in microcirculation has increased hematocrit (ratio of RBC volume to total blood volume)
as a result, blood flow slows down (stasis)
what are the roles of each of these endothelial molecules in leukocyte infiltration?
a. P-selectin
b. E-selectin
c. GlyCam-1, CD34
d. ICAM-1
e. VCAM
a. P-selectin: rolling
b. E-selectin: rolling/adhesion
c. GlyCam-1, CD34: rolling (CAM = cell adhesion molecule)
d. ICAM-1: adhesion
e. VCAM: adhesion
two main groups of opsonization factors
- IgG (heat stable): recognized by Fc receptors
- C3b complement proteins (heat labile): recognized by complement receptors (CR)
how do cells produce more energy for phagocytosis, an energy-requiring process accompanied by a burst of metabolic activity and oxygen consumption?
What is the outcome of this process?
glucose metabolized via the hexose monophosphate shunt (HMS): converts glucose phosphate to ribulose 5-phosphate and oxygen
—> generates NADH, NADPH
NADH oxidase converts oxygen to hydrogen peroxidase (required for bacterial killing)
NADPH oxidase generates superoxidase
chronic granulomatous disease
X-linked or AR, affects males mostly - recurrent infections with granulomas
lack of NADPH oxidase activity —> leukocytes do not show burst of metabolic activity that occurs with phagocytosis
remember that NADPH oxidase generates superoxide
Chediak-Higashi syndrome
decreased leukocyte functions because of mutations affecting proteins involved in lysosomal membrane traffic
causes increased CNS infections
pt presents with recurrent CNS infections. PMH includes genetic testing that showed mutation in a protein involved in lysosomal memrbane trafficking. FHx includes a grand-parent who suffered similar recurrent infections
what is your diagnosis
Chediak-Higashi syndrome (AR): decreased leukocyte function due to mutations affecting proteins involved in lysosomal membrane trafficking