Pathology and inflammation Flashcards
1
Q
hyperplasia
A
increase in number of cells in response to increased stimulation or stress; may be pathological (menopausal endometrial hyperplasia, skin warts) or physiological (breast hyperplasia during puberty and pregnancy, wound healing); reversible, but may increase cancer risk
2
Q
hypertrophy
A
increase in size of existing cells in response to increased stimulation or stress, particularly trophic or mechanical triggers; includes enlarged nuclei and an increase in proteins and organelles in the cells; often leads to an increase in the size of the corresponding organ; may be pathological (hypertensive cardiac hypertrophy) or physiological (increased muscle mass in response to exercise)
3
Q
atrophy
A
decrease in size of existing cells; includes decreased protein synthesis, increased degradation, decreased cell function (NOT cell death); may be pathological (muscle atrophy due to peripheral nerve damage) or physiological (menopausal endometrial atrophy)
4
Q
metaplasia
A
change in cell/tissue type via reprogramming of stem cells in response to increased stimulation or stress; may increase cancer risk
5
Q
ischemia
A
reduced or absent blood flow to a particular tissue
6
Q
necrosis
A
form of cell death due to irreversible cell injury; features include increased eosinophilia, nuclear shrinkage/fragmentation/disappearance, breakdown of plasma membrane
7
Q
hydropic change/vacuolar degeneration
A
form of reversible cell injury; cells swell and exhibit membrane blebs, as well as vacuoles corresponding to distended endoplasmic reticulum; results from failure of membrane pumps to maintain homeostasis; example: acute tubular necrosis due to reperfusion injury
8
Q
fatty change
A
form of reversible cell injury due to toxic or hypoxic stress; appearance of lipid vacuoles in cell cytoplasm; primarily in cells dependent on fat metabolism, when fatty acid transport systems are intact but degradative enzymes are damaged/deficient; example: fatty liver disease due to alcohol use or obesity
9
Q
liquefactive necrosis
A
necrotic pattern caused by bacterial/fungal infection or brain infarct; features include complete tissue digestion/semi-liquid consistency, presence of PMNs, pus/abscesses, no residual tissue architecture
10
Q
coagulative necrosis
A
necrotic pattern caused by hypoxic or anoxic injury due to ischemia; features include persistence of dead cells, intact outlines/tissue architecture, loss of cellular details; common in solid organs (except the brain); generally presents as wedge shape that points to the infarct
11
Q
caseous necrosis
A
necrotic pattern characteristic of tuberculosis infection; features include cheese-like appearance, fragmented/coagulated cells with loss of tissue architecture/cell outlines, surrounded by granuloma
12
Q
gangrenous necrosis
A
necrotic pattern describing ischemic coagulative necrosis of extremities or GI organs; “dry” when strictly ischemic, “wet” when also infected (shows liquefactive characteristics); features similar to coagulative necrosis, include black discoloration of tissue
13
Q
fat necrosis
A
necrotic pattern caused by injury/trauma to fatty tissue, which causes lipase release, liberation of fatty acids, and subsequent calcium saponification; features include chalky white appearance of tissue; typical of acute pancreatitis or trauma to the breast
14
Q
fibrinoid necrosis
A
necrotic pattern caused by deposition of immune complexes along vascular walls; features include fibrin-like, bright pink, amorphous appearance; typical of vasculitis
15
Q
antigen
A
a molecule that stimulates an adaptive immune response
16
Q
epitope
A
specific region of a macromolecular antigen to which lymphocyte receptors bind
17
Q
immunogen
A
a molecule that induces an immune response (may or may not include a lymphocyte response)
18
Q
labile cells
A
continuously-dividing cells (examples: hematopoietic cells, surface epithelia)
19
Q
stable/quiescent cells
A
tissues that normally have minimal/no replicative activity, but are capable of proliferation in response to injury (examples: solid organ parenchyma, endothelial cells, fibroblasts, smooth muscle cells)
20
Q
permanent cells
A
non-proliferative tissues, even in the presence of cell stress/injury (examples: neurons, cardiac muscle cells)
21
Q
reperfusion injury
A
tissue damage caused by sudden rapid increase of ROS production due to reperfusion following ischemia, as well as accompanying inflammation induced by ROS injury
22
Q
lipofuscin
A
indigestible material resulting from lipid peroxidation; “wear and tear” pigment, increases with aging; visible in heart, liver, and brain
23
Q
anthracosis
A
carbon pigment that accumulates in lung tissue/lymph nodes; inhaled in air, then phagocytosed by alveolar macrophages and carried to lymph nodes; common in city-dwellers, coal miners, and smokers
24
Q
hemosiderin
A
hemoglobin-derived pigment containing iron (yellow to golden brown), present in tissue where there has been hemorrhage, systemic deposition present with increased iron absorption, some anemias, transfusions, and some hereditary conditions
25
dystrophic calcification
calcification of non-viable, damaged, or dying tissues in the presence of normal serum calcium levels; tissue is basophilic on H&E; examples include atheromas, aortic valves in the elderly, lymph nodes with long-standing TB
26
metastatic calcification
calcification of normal tissues due to increased serum calcium levels (i.e. elevated parathyroid hormone, destruction of bone, vitamin D intoxication, renal failure); common in interstitial tissues of lung, kidney, and gastric mucosa
27
Barrett's esophogus
metaplasia of the distal esophagus in which esophageal squamous epithelium (normal) changes into glandular epithelium similar to that of the gastric mucosa in response to chronic acid reflux; protects the esophagus from damage by stomach acid, but predisposes for glandular carcinoma
28
myositis ossificans
ossification of muscle due to trauma or injury
29
type I diabetes
Type IV autoimmune disease caused by production of pathogenic T-cells against pancreatic islet antigens; characterized by impaired glucose metabolism and vascular disease
30
IPEX
immune dysregulation, polyendocrinopathy, enteropathy, X-linked; autoimmune disease caused by mutations in Foxp3/loss of T-regs, affects infant boys; characterized by inflammatory bowel disease, severe eczema, food allergies, T1DM, thyroiditis, autoimmune hemolytic anemia, thrombocytopenia, hypergammaglobulinemia, very high IgE levels; lethal if not treated aggressively
31
celiac disease
gluten enteropathy in which gladden in food is altered upon binding to tissue-transglutaminase to become immunogenic; possible molecular mimicry between tissue-transglutaminase and intestinal wall mediates Ab response
32
CH50
total complement activity; used to test for complement defects; if result is low, then individual component testing should be ordered
33
dihydrorhodamine test
diagnostic test for chronic granulomatous disease; DHR is oxidized by PMNs when stimulated with forbid myristate acetate, oxidized form is fluorescent, absence of fluorescence = positive for CGD
34
chronic granulomatous disease
usually presents by age 2; caused by functional absence of respiratory burst in neutrophils and monocytes (mutation in any of four subunits in NADPH oxidase), though hypomorphic protein may be able to handle most microbes; may be X-linked; pts present with pneumonia, adenopathy/abscesses (hepatic abscess common), sepsis, osteomyelitis, infection with catalase (+) bacteria; Dx req's DHR or NBT (DHR preferred)
35
leukocyte adhesion deficiency
caused by mutation in LAD-1/Mac-1 (common integrin beta chain for CD18), LAD-2 (only in middle east), or other integrins, which leads to impaired leucocyte chemotaxis, phagocytosis, and margination; pts present with recurrent pyogenic infections, delayed umbilical cord detachment, leucocytosis, inability to form pus; infections require aggressive Abx treatment, bone marrow transplant in severe cases
36
CBC with differential
complete blood count that includes specific counts of neutrophils, lymphocytes, monocytes, basophils, and eosinophils
37
ANC
absolute neutrophil count - important to diagnose neutrophil defects, including chronic granulomatous disease, congenital/cyclic neutropenia, and leukocyte adhesion deficiency
38
delayed-type hypersensitivity
Type IV hypersensitivity reaction, T-cell mediated, leads to macrophage activation, cytokine-mediated inflammation, cell lysis
39
DiGeorge syndrome
AKA 22q11.2 deletion syndrome; caused by a micro deletion in chromosome 22q11.2 on the TBX1 gene (homeobox); clinical syndrome characterized by CATCH22 (cardiac defects, abnormal facies, thymic hypoplasia, cleft palate, hypocalcemia, 22nd chromosome); also commonly exhibit immunodeficiency/autoimmunity; Dx req's FISH, chromosomal microarray/DNA duplication test
40
common variable immunodeficiency
most common clinically-significant Ab deficiency; onset at any age (>2 y.o.), no known monogenic cause; characterized by low IgG and low IgA or IgM, lymphocyte levels generally normal; pts present with frequent URI/GI infections and bronchiectasis/interstitial lung disease, often die of pulmonary disease, cancer, autoimmune complications, liver disease, or infection; Dx based on Ig count, absent isohemagglutinins, poor vaccine response (pneumavax)
41
agammaglobulinemia
presents within first year of life, often X-linked (XLA); X-linked form caused by mutation in Btk gene (part of surrogate light chain signaling pathway), leading to lack of B cells (failure to differentiate) and panhypoglobulinemia; pts present with recurrent otitis, sinusitis, pneumonia, untreated may lead to bronchiectasis and infection with encapsulated bacteria or mycoplasma spp.; also have severe enteroviral infections (vaccine-related polio); Dx req's quantitative Ig (IgG, IgA, IgM), flow cytometry; Tx with IV globulin
42
complement deficiency
may present at any age; early complement (C2, C4) defects present with sinopulmonary infections, increased susceptibility to S. pneumoniae and H. influenzae, autoimmune disease (such as SLE or glomerulonephritis); late complement (C5-C9) defects present with increased susceptibility to Neisserial infections (generally present with first infection at ~17 y.o.); C3 defects are very rare and present with severe pyogenic infections; diagnostic testing includes CH50 (only complement deficiency if CH50 = 0 - if it's low, then it's a consumption issue, like lupus)
43
systemic lupus erythematosus
Type III autoimmune disease caused by antibody production against sDNA, histones, and other nuclear proteins, which leads to immune complex deposition; characterized by anti-nuclear antibody (ANA) production, nephritis, rash (malaria, discoid), and vasculitis; complement defects lead to early onset
44
TREC (T-cell receptor excision circles)
nonreplicating circular pieces of DNA in naive T-cells generated in the process of making a T-cell receptor; measured via real-time qPCR; low levels diagnostic of SCID
45
rheumatoid arthritis
Type IV autoimmune disease caused by T-cell-mediated (likely B-cell also) inflammation of the joints/reactivity to joint antigens; pathology includes pants formation, aggregates of mononuclear cells; oligoclonal T-cells release IL-1, IL-6, and TNF, which activate macrophages/inflammation; B-cells aggregate in synovium
46
multiple sclerosis
Type IV autoimmune disease caused by production of pathogenic T cells agains myelin proteins; characterized by demyelination of neurons in the central nervous system by T-cells and macrophages, sensory and motor dysfunction
47
X-linked SCID
severe combined immunodeficiency; most common etiology of SCID, caused by a mutation in the gamma-chain of the IL-2 receptor, which prevents both T-cell survival and B-cell activation by T-cells (gamma chain is also a shared component for other IL receptors); presents within first year of life, usually around 3 m.o.; pts lack T cells and NK cells (though they may possess mom's T-cells if they crossed the placenta during birth), B cells are present but nonfunctional; characterized by pneumocystis pneumonia, otitis media, thrush, intractable diarrhea, FTT; 100% mortality w/o bone marrow transplant; Dx req's CBC, lymphocyte enumeration (should lack naive T-cells)
48
APECED
autoimmune polyendocrinopathy candidiasis ectodermal dystrophy - an autoimmune adrenal and parathyroid disease caused by a defect in the AIRE gene (transcription factor directing expression of self antigens in the thymus); features include hypothyroidism, hypogonadism, vitiligo, pernicious anemia, fungal infections
49
autoimmune lymphoproliferative syndrome (ALPS)
autoimmune disease caused by mutations in Fas or Fas-L, leads to failed central tolerance; characterized by lymphadenopathy, splenomegaly, autoimmune cytopenias, elevated IgG, IgA, and IgM, elevated double-negative T-cells
50
T-regulatory cells
express transcription factor Foxp3, generated by self antigens in thymus, activated by IL-2, inhibit mature T-cells via contact-dependent (CTLA-4, surface-bound TGF-beta, perforin and granzyme) and contact-independent (secreted TGF-beta and IL-10) mechanisms
51
JONES criteria (O=heart)
mnemonic describing major diagnostic criteria for acute rheumatic fever: joints, heart, nodules, erthema marginatum, sydenham's chorea; diagnosis requires two major criteria or one major and two minor criteria (minor: fever, arthralgia, elevated acute phase reactants, prolonged PR interval)
52
rheumatic fever
diagnosed by the JONES criteria (req's two major or one major and two minor), complication of S. pyogenes infection expressing M proteins that are structurally similar to heart muscle; type II hypersensitivity reaction, caused by production of antibodies to myosin
53
IgA deficiency
most common Ab deficiency; characterized by extremely low IgA, normal IgG and IgM, normal T-cell function; vast majority of pts are asymptomatic, may have more frequent sinopulmonary/GI infections, atopic disease, celiac disease, autoimmune disease; may be associated with production of heterophiles Abs (causes false neg/pos diagnostic tests)
54
specific antibody deficiency
pts have normal IgG, IgA, IgM, and T-cell function, but exhibit abnormal specific antibody responses to immunization (esp. polysaccharide antigens); may be a developmental delay in Ab response (kids often only need IV IgG for one year)
55
acute inflammation
short-term (minutes to hours) inflammatory response characterized by neutrophil infiltrate; generally mild/self-limiting, though may have prominent systemic signs (incl. fever, leukocytosis, etc.); stimulated by infection, physical trauma, chemical agents, tissue necrosis, foreign bodies, and hypersensitivity reactions
56
chronic inflammation
long-term (days) inflammatory response characterized by monocyte/macrophage and lymphocyte infiltrate; often severe and progressive, though signs and symptoms may be subtle; often involves active inflammation, tissue injury, and healing occurring at the same time, as well as angiogenesis and fibrosis; stimulated by persistent infections, prolonged exposure to toxic agents, and immune-related inflammatory diseases
57
cardinal signs of inflammation
calor (heat), rubor (redness), tumor (swelling), dolor (pain), functio lasea (loss of function)
58
diapedesis
movement of leukocytes through vessel wall
59
chemotaxis
movement of a cell toward an injury site (or other stimulus) due to a concentration gradient of soluble chemotactic factors
60
transudate
extracellular fluid that accumulates due to increased intravascular hydrostatic pressure or decreased colloid osmotic pressure; low protein content, low specific gravity
61
exudate
extracellular fluid that accumulates due to vasodilation and increased vascular permeability under inflammatory conditions; high protein content, high specific gravity; when rich in leukocytes (particularly neutrophils), is termed "pus"
62
abscess
central area of necrotic tissue surrounded by preserved neutrophils, dilated vessels, and fibroblastic proliferation
63
ulcer
local defect on the surface of an organ or tissue characterized by sloughing of surface covering and necrotic inflammatory tissue
64
granuloma
locus of granulomatous inflammation characterized by prominent activated macrophages with epithelioid appearance, multinucleated giant cells (stimulated by IFN-gamma), collar of lymphocytes and plasma cells, surrounding fibrosis; develops in due to specific infections, inert foreign bodies, and autoimmune reactions
65
pyrogen
a molecule that induces a fever; includes LPS, IL-1, TNF; these mediators ultimately stimulate prostaglandin (esp. PGE2) production, which resets the hypothalamus
66
acute phase reaction
AKA systemic inflammatory response syndrome (SIRS), characterized by fever, elevated acute-phase proteins (c-reactive protein, fibrinogen, serum amyloid A protein; synthesized by the liver, stimulated by IL-6), and leukocytosis
67
allergen vs. irritant
allergens elicit IgE-mediated immune reactions that require prior sensitization to develop and are not dose-dependent; irritants stimulate an adverse inflammatory response in all individuals that is not mediated by IgE and is dose-dependent
68
tryptase
enzyme released by mast cells from pre-formed stores; exists in two forms, alpha is constitutively released, beta is only released with mast cell activation, remains identifiable in the serum for up to 4 hours after release, causes remodeling of connective tissue matrix; mast cells are only source
69
IL-5
produced by Th2 cells (differentiate due to presence of IL-4), mediates allergic response, esp. eosinophil activation/conversion to hypodense phenotype, augments beta2 integrin-mediated adhesion and transendothelial migration
70
IL-4
stimulates differentiation of Th2 cells via expression of GATA-3 transcription factor; also produced by Th2 cells, mediates allergic response, esp. IgE class switching
71
IL-13
produced by Th2 cells, induces IgE class switching
72
eotaxin
CCL11; found at sites of allergic inflammation
73
leukotrienes
lead to eosinophil migration, smooth muscle contraction, vascular permeability, and mucus hypersecretion
74
MBP
major basic protein, secreted by eosinophils, causes mast cell activation, helminthotoxic
75
hypersensitivity
immune response against an otherwise inert environmental stimulus
76
eosinophils
prominent in type I hypersensitivity/allergic reactions; elevated by NAACP (neoplasia, asthma, allergy, connective tissue disease, parasitic disease); possess CCR3, the only known receptor for eotaxin; possess crystalloid granules that contain very basic proteins; secretes IL-5, GM-CSF (promotes own survival), ROS, leukotrienes, PAF, and charcot-leyden crystal protein (sign of degranulation)
77
immediate vs. late-phase reactions
immediate reaction occurs immediately (within 15-30 minutes) after second exposure to an antigen and involves mast cell release of histamine, tryptase, LTC4, PGD2, IL-4, and other cytokines; late-phase reaction occurs 4-6 hours after exposure and involves recruitment of eosinophils, Th2 cells, and basophils, as well as release of prostaglandins (PGD2, PGE2, PGF2a), kinins, histamine, MBP (major basic protein), ECP (eosinophil cationic protein), EDN (eosinophil-derived neurotoxin), and leukotrienes (LTB4, LTC4)
78
histamine
released from mast cells, basophils, and platelets in connective tissue near vessels in response to IL-1, trauma, complement, etc.; induces vasodilation and increased vascular permeability via endothelial cell contraction (leads to erythema, warmth, and edema/swelling); released immediately from pre-formed stores
79
allergic rhinitis
nasal congestion, rhinorrhea, rhinitis, nasal and ocular pruritis, and conjunctivitis due to type I hypersensitivity reaction (cross-linking of IgE in nasal mucosa and ocular conjunctiva with specific antigen exposure)
80
asthma
wheezing, shortness of breath (difficulty exhaling), increased mucus secretion and plugging of the airways due to IgE-mediated disease in the lower airways; inflammatory cell infiltrate includes eosinophils and lymphocytes; long-term effects include denudation of airway epithelium, mucus gland hyperplasia/hypersecretion, smooth muscle cell hyperplasia, submucosal edema, vascular dilation, and fibrin deposition/airway remodeling
81
anaphylaxis
type I hypersensitivity reaction characterized by warmth, itchy palms/soles, racing heart, wheezing/difficulty breathing, fainting; mediated by histamine, leukotrienes, and nitric oxide
82
serum sickness
systemic reaction from injection of large quantities of foreign proteins; occurs 7-10 days after exposure to antigen (to allow class switching from IgM to IgG), characterized by flu-like symptoms with urticarial rash, arthritis, and glomerulonephritis; repeat exposures require much shorter time until onset of symptoms
83
Goodpasture syndrome
type II hypersensitivity reaction in which Abs are made against type IV collagen in basement membranes of glomeruli and lung alveoli; characterized by nephritis and lung hemorrhages
84
contact dermatitis
type IV hypersensitivity reaction in which chemical compounds exposure to the skin causes binding of compounds with self proteins; generates immune response; macrophage-mediated inflammation
85
antihistamine
lowers the threshold of mast cell release
86
corticosteroids
induce rapid apoptosis of eosinophils, inhibit IL-5 production, inhibit AP-1 and NF-kB
87
epinephrine
temporarily alleviates type I hypersensitivity reaction/anaphylactic shock
88
bradykinin
plasma protein produced in response to endothelial injury; induces vasodilation, increased vascular permeability, and sensitization to pain
89
TNF
pro-inflammatory cytokine released by innate immune cells in response to activation of TLRs by extracellular microbes, activates endothelium and leads to adhesion molecule expression; only cytokine that exists as a preformed mediator
90
IL-1
pro-inflammatory cytokine released by innate immune cells due to activation of the inflammasome by products of dead cells and some microbes; promotes recruitment of leukocytes and secretion of more cytokines
91
selectins
adhesion molecules located on endothelial cells, platelets, and leukocytes; only expressed upon stimulation by mediators (histamine, thrombin, etc.); aid in loose attachments
92
integrins
adhesion molecules located on leukocytes; expressed upon stimulation by chemokines secreted by endothelial cells; ligands on endothelial cells expressed upon stimulation by TNF and IL-1 from macrophages; aid in stable attachment of leukocytes to endothelium
93
platelet activating factor
attracts eosinophils and other leukocytes; activates eosinophils, neutrophils, and platelets
94
regeneration
growth of cells and tissues to replace lost structures; usual response of skin, liver, intestine to injury; no scar remains
95
healing (and repair)
occurs when complete restitution is not possible (severe damage, persistent/chronic damage, permanent tissue); requires remnants of injured tissue, endothelial cells, and fibroblasts; parenchyma also requires supporting stroma; generally involves collagen deposition; steps include angiogenesis --> fibroblast migration/proliferation --> extracellular matrix deposition --> maturation/remodeling of fibrous tissue; driven by TGF-beta, PDGF, and FGF
96
angiogenesis
branching/generation of new blood vessels from preexisting blood vessels using angioblasts (endothelial precursor cells) from bone marrow; driven by NO, VEGF, and FGF
97
granulation tissue
specialized tissue seen in tissue healing/scar formation; present by 3-5 days post-injury, contains new vessels, inflammatory cells, and fibroblasts; high in collagen, appears purple on H&E (indicative of ongoing healing/repair); precedes mature scar formation
98
extracellular matrix
made up of interstitial matrix (3D amorphous gel, made by fibroblasts) and basement membrane (made by mesenchyme and epithelium), synthesized largely of collagen and elastin; provides mechanical support, regulates cell proliferation, provides scaffold for healing, stores growth factors, and creates "microenvironment"
99
healing by primary intention
when a wound closes by approximation of clean-cut wound margins (i.e. placement of a graft, surgical incision with stitches/staples); applies to acute wounds within 24 hours of injury (before granulation tissue); may result in scar formation beneath wound site; wound clots --> neutrophils/re-epithelialization --> macrophages/granulation tissue --> increased granulation tissue/collagen deposition --> scar formation (total process: weeks)
100
healing by secondary intention
when a wound is left open, often due to having large opening or irregular edges, and allowed to close by epithelialization, granulation tissue, and wound contraction; commonly used in management of infected wounds; characterized by more intense inflammatory response, large fibrin clot, more necrotic material, larger amount of granulation tissue, substantial scar formation and thinned epidermis
101
embryonic stem cells
totipotent/pluripotent stem cells in an embryo that can differentiate into all tissues
102
adult stem cells
lineage-specific stem cells present in labile and stable tissues; some tissues contain multipotent progenitor cells that retain broad differentiation capabilities (i.e. bone marrow)
103
acute retroviral syndrome
sickness that presents 1-4 weeks post-HIV exposure, usually lasts less than 2 weeks; symptoms include fever, lymphadenopathy, sore throat, rash, joint pain, etc.; usually occurs during acute infection/window period, in which HIV virions are detectable in the blood but no antibodies are yet present
104
anti-retroviral therapy
anti-HIV drugs that target various stages in the viral replication cycle: CCR5 antagonists, fusion inhibitors, NNRTI/NRTIs, integrase inhibitors, protease inhibitors
105
vascular endothelial growth factor (VEGF)
secreted by mesenchymal cells; induces angiogenesis in injury and in tumors
106
fibroblast growth factor (FGF)
secreted by macrophages, mast cells, endothelial cells, fibroblasts, and others; induces angiogenesis, promotes migration of fibroblasts, epithelial cells, and macrophages
107
platelet-derived growth factor
secreted by platelets, macrophages, endothelial cells, smooth muscle cells, and epithelial cells; induces fibroblast, smooth muscle cell, and endothelial cell proliferation and migration; stimulates production of extracellular matrix
108
transforming growth factor beta
secreted by platelets, endothelium, epithelium, lymphocytes, macrophages, smooth muscle cells, and fibroblasts; suppresses endothelial proliferation/migration and acute inflammation; stimulates production of extracellular matrix proteins
109
graft vs. host disease
inflammatory process in context of a bone marrow transplant in which pre-transplant conditioning causes tissue damage/inflammation and upregulation of cytokines, which activates host APCs; upon graft completion, ACPs activate donor T-cells, which recognize host tissue as foreign and attack it (CD8+, macrophages, NK cells); commonly-affected tissues include skin, GI tract, and liver
110
Ehlers-Danlos syndrome
genetic defect in collagen synthesis or structure; may be caused by one of several collagen mutations (classic is deficient production of type V collagen); symptoms include hyperextensible/fragile skin, hypermobile joints, rupture of internal organs and large arteries, and poor wound healing
111
Marfan syndrome
genetic mutation affecting fibrillin; symptoms include degeneration of aorta (aneurysm and dilation), dislocated lens, abnormalities of aortic and mitral valves, long legs/arms/fingers, and hyperextensible joints
112
matrix metalloproteinase
zinc-containing enzymes that participate in scar remodeling/maturation; degrade collagen and other extracellular matrix proteins, ultimately assist in contraction of the scar; synthesized/secreted by fibroblasts, macrophages, neutrophils, and others; regulated by growth factors and cytokines
113
allograft
implantation of a tissue from a genetically distinct individual of the same species
114
human immunodeficiency virus
virus specific for human CD4+ cells; enters body via blood or mucous membranes via infected blood, semen, vaginal secretions, breast milk, CSF, synovial/pleural/pericardial/peritoneal fluid, or amniotic fluid; infects CD4+ cells, gets carried to lymph nodes to establish reservoir; diagnosed via antibody testing (not accurate in acute infections), RNA testing, or p24 antigen testing; fourth-generation EIA testing tests for both Abs and p24 Ag
115
acquired immunodeficiency syndrome
syndrome characterized by HIV infection and a CD4+ count of 250 or less
116
alloantigens
allogenic MHC molecules (major) and other allogenic proteins possessing genetic polymorphisms (minor); allogenic MHC often resembles peptide-loaded self MHC molecules; immune system also reacts to allogenic MHC directly
117
hyperacute rejection
rejection of a xenogeneic graft due to presence of pre-formed Abs; occurs within minutes of transplantation
118
acute cellular rejection
rejection of an allogeneic graft due to activation of recipient cell-mediated immune responses against alloantigens (can also occur as acute humoral rejection, in which humoral systems are activated); in immunocompetent individuals, occurs within days to weeks; in immunocompromised individuals, occurs within months to years
119
chronic rejection
rejection of an allogeneic graft that involves a chronic inflammatory response against the graft; occurs within months to years, is the major cause of graft failure; involves vascular changes, interstitial fibrosis, loss of parenchyma, ischemia, atrophy, etc.
120
fibrillin
protein component of the extracellular matrix that, together with elastin, forms elastic fibers that allow for recoil properties; abundant in aorta, lens, and ligaments
121
fibronectin
adhesive glycoprotein, major component of interstitial ECM
122
laminin
major protein component of basement membranes
123
keloid
raised epithelialized scar due to excess collagen deposition, possibly due to increased activity of TGF-beta and IL-1
124
fibrosis
wound healing that occurs in response to chronic/persistent injury or inflammation, involves destruction and regeneration of ECM, collagen deposition, nodule formation; examples include liver cirrhosis, interstitial lung disease, rheumatoid arthritis, chronic pancreatitis
