Exam 4 Flashcards
Osteoarthritis
degeneration of articular cartilage with hypertrophy of bone, joint space loss, subchondral cysts, sclerosis and osteophytes
what joints are involved in OA?
DIPs, PIPs, 1st CMC, weight bearing - hips and knees, Spine - cerivical and lumbar, 1st MTP
Heberden’s
DIPs
Bouchard’s
PIPs
Predisposing factors to OA
Age, obesity, occupational risks, trauma, or secondary OA due to inflammatory disorders like RA, spondylo, or metabolic disorders
sports and OA
no increased risk, exercise may be protective
Cartilage components
avascular and no nerves 1) collage II 2) proteoglycans 3) matrix proteins 4) chondrocyes 5) 70% water
Proteoglycans
in cartilage - chondroitin and keratin sulfate linked to hyaluronic acid - hydrophilic
Matrix proteins in cartilage
Metalloproteinases - like collagenases, gelatinases, stromeylsins and Tissue inhibitors of metalloproteinases TIMPS
Chondrocytes
main cell of cartilage that produces the proteins in cartilage
aggrecans
chondroitin and keratin sulfates bound to collagen. Forms a weave that acts like a sponge to hold onto water
changes to cartilage in OA
increase chondrocytes, increase MMPs, decrease TIMP, proteglycans, Increase water. This is due to a mechanical injury, inflammation, metabolic hit of cartilage. Looses the weave and forms a dish rag instead of a sponge.
Does OA have systemic feaures?
NO - lacks them
Synovial fluid in OA
non-inflammaotry, type I fluid with 200-2000 WMC
Pathophysiology of OA
chondrocytes and synovium produce inflammatory mediators for cartilage destruction - IL1, NO, protsaglandins; they also activate complement and adipokines.
IL-1 release in OA
stimulates MMPs, PGE2, NO, IL6 produciton
NO release in OA
increases MMPs, inhibits protoglycan, induces chondrocyte apoptosis.
Prostaglands in OA
increase production and activation of MMPs
what other cytokines are produces in OA?
TNF, IL6, IL17, IL18
Adipokines
are our own fact cells that make IL6 that go into the liver to make acute phase reactants like CRP. - metabolic aspect of OA.
Radiological findings in OA
Joint space loss, sclerosis, subchondral cysts, osteophytes
Patient will tell about OA
localized pain, worse with use. Stiffness for less than 30 minutes.
Rheumatoid Arthritis - basic
systemic, inflammatory, autoimmune disorder that results in peripheral, symmetric, *synovitis with cartilage and bone destrcution.
Joint involvement in RA
Bilateral and symmetric small joints of hands and feet (sparing DIPs), medium and large too.
X-rays of RA
marginal joint erosions and deformities
Etiology of RA
arthritogenic peptide in host genetically suseptible due to a HLA-DR4 and HLA-DR1 mutation.
HLA-DR4
mutation in 3rd hypervariable region of the MHC II binding cleft that increases the susceptibility and severity of the RA.
RF
antibody that detects Fc profession of IgG. usually composed of IgM, but can be IgG and IgA. Not a very sensitive marker of RA (85%). Produced in synovial tissue by plasma cells. RF-IgG immune complexes are pathogenic and form rheumatoid nodules over extensor system and lungs
Anti CCP
anti cyclic citrullinated peptide antiboides that react with synthetic peptides contains citrulline.
Cirulline
modified arginine residue that is commonly seen in RA patients
Sensitivty vs. Specificity of anti-CCP
90% senstivie and 90% specific
RF sensitivity and specificy
80% sensitive, 80% specific
RF and anti-CCP sensitivity and specificity
rare only 40% sensitive and 100% specific
how often do anti_CCP occur
most frequently in those with HLA-DR4 epitope, due to enhanced binding of peptides to cirullination.
Pannus
characteristic of RA, containing major T lymphocytes, macrophages, and some fibroblasts, plasma cells, DCs. Located adjacent to bone and cartilage that chews away the erosions at margins of the joint.
Basic one liner of RA
disease of synovium
basic one liner for OA
disease of cartilage
cell types in synovial fluid of RA
PMNs
where are PMNs in RA?
in synovial fluid, but NOT synovium tissue.
Synovium tissue in RA contains…
contains CD4 lymphocytes and Th17; more often than B-cells and plasma cells; IL2 and IFNgamma are sparse. no PMNs
Role of cells in RA synovium
CD4 memory cells modify and amplify local immune response through nation recognition.
Extra-articular manifestations of RA
RF-IgG compelx caues induced vasculitis; rhematoid nocules, eye lung, pericardium, peripheral nerves.
Pathophy of RA
unknown antigen is consumed by immune system at diagnosis, but altered proteoglycans, collagen, cirulinated peptides propogate the disease (not the antigen)
what patient experiences in RA
morning stiffness, fatigue, pain that improves with activity, rest makes worse
Lab values in RA
elevated RF, ESR, CRP, anti-CCP antibodies
Imaging of RA
loss of joint space, erosion of marginal distribution, soft tissue swelling, osteopenia
Risk factors of RA
female, any age, smoking
Gout - definition
Tissue deposition of Monosodium urate crystals due to hyeruricemia (MSU supersaturation of extracellular fluid)
Joints in Gout
1st MTP (podagra), Cool peripheral joins of lower and upper extremities.
Hyperuricemia
over production or under excretion of uric acid. (90% are under excretors)
Uric Acid
produce of purine metabolism, but humans lack the Uricase enzyme to oxidize uric acid into allegation form.
X-linked conditions for overproduction or uric acid
PRPP synthtase overactivity, and HGPRT deficiency.
Diagnosis of Gout
arthrocentesis - needle biopsy with needle shaped crystals, negatively birefringement.
Increased PRPP synthetase
incrases production of PRPP-glutamine to cause the pathway to form uric acid
decreased HGPRT
inhibits the reaction from going backward to promote more uric acid instead of guanlyic acid or inosinic acid.
Xanthione oxidase
inhibited by allopurinol and febuxosat that covers Xanthine into uric acid.
Inflammation induced Gout
Endogenous MUS crystals trigger TLR2/4 of inflammatory response. These are on monocytes, macrophages, synovial cells and activate NFkB to pour out inflammaotry cytokiesn and attract PMNs. 2) MSU crystals are internalized to activate NLRP3 inflammation via activation of Caspase 1 to results in IL-1 cleavage and release.
Self limiting nature of Gout
Cellular response due to protein coatings: gig coating promotes phagocytosis by PMNs. As time goes on you switch to ApoB coating that inhibits phagocytosis and the immune response.
2) phagocytosis decreases crystal concentrations
3) heat of inflammation, increases solubility
4) ACTH secretion supresses inflammation
5) IL1 and TNF anti antibodies are produced to modulate the inflammation
Calcium Pyrophosphate Dihydrate deposition
Abnormal pyrophosphate metabolism (PPi) - metabolism of NTPs from chondrocytes., PPi contacts calcium to form crystals.
PPi generation on chondrocytes
NTP pyrophosphohydrolase NTPPPH hydrolyzes phosphodiester1 bond to make NMP and PPI.
2) mutations in ank gene (ANKH) case transmembrane PPi transporter to all egression of excess PPi.
Visualization of Ca Pyrophospahte dehydrate deposition
PPi precipitates with Ca to form crystals in midzonal cartilage layers - shedding, strip mining. Rhomboid shape with positive birefringement
Predisposition to Gout
Men over 30, shelfish, alcohol
Underexcretion of uric acid
activation of URAT1 to decrease excretion
Lesch-Nyhan
complete deficiency in HGPRT
Seronegative spondylarthropaties
Axial arthritis of spine, sacroilitis, periphery (small and large), characterized by *enthesitis, mucocutaneous lesions, Uveitis
Enthesitis
characterisitc of seronegative spondylarthropaties. - inflammation where ligament, tendon, and fibrossseous junction meet bone.
Systemic effects of Ankylosing Spondylitis
osteoporosis, uveitis, microscopic colitis
lab values of Ankylosing spondylitis
High ESR, negative RF, negative ANA
Genetic predisposition to Spondylarthropaties
HLA-B27 - associated with negative RF and ANA (sero negative).
what is in the synovium of Spondylarthropaties
increased expression of TNFalpha
HLA-B27
Increased prevalence in Caucasians (6-9%), but relative low incidence of sponylarthropaties (0.1-0.2%. Thus there is low chance of having Spondyloarthropaties, and a 20% if you have the mutation and first degree relative. Only accounts for 40% of genetic risk -
Concordance of spondyloarthropties
60%
Reative Arthritis
due to infectious diarrhea or urethritis. Asymmetric, oligoarticular of the lower extremities, dactylitis, hips spared
Triggers of Reactive arhritis
transporttion of bacteria inside by monocytes (chlamydia) via molecular mimicry, arthritogenic peptide, Heavy chain theory, Unfolded protein hypothesis, TH2 response.
systemic effects of Reactive arthritis
inflammatory eye, musculocutaneous lesions, aortas, cardiac conduction defects
Arthritogenic peptide hypothesis
unique presentation of process peptide by HLA-B27
HLA-B27 heavy chain theory
causes NK cell activation
Reiter’s syndrome
conjunctivitis, urthritis, arthritis
HLA-B27 ER stress response
misfolded HLA-B27 initiates stress response to cuase IL23, IL17 to response to IL-6.
ERAp1
helps trim proteins as they feed into the ER
Systmic Lupus Erythromatses
chronic, autoimmune disease that affects multiple organs - skin, joints, serial, luns, kidneys, CNS
What causes SLE?
disdirectied recognition of self as foreign; requires both the T and B cell lectures; misdirected recognition of self as foreign.Antibody response requires antigen driven CD4 cells.
loss of t and b cells can happen
Pathophysiology of SLE
1) auto reactive B and T cells; Nucleic acids stimualte TLR receptors on DC cells to pump out IFN-alpha to represent to auto reactive Tcells. This leads to B cell stimulation and autoantibody creation. 2) NETOSIS - when apoptosis occurs of PMNs, they spew their nucleus out and trap bacterial pathogens. They trap, but the trap is made of DNA —> more autoAb.
Genetics of SLE
Increased risk among relatives, 35% concordance rate, associated with HLA_DR3 and C4A null allel (greatest risk)
Popualtions of SLE
AA, asians, hispanic americans
Environmental factors of SLE
female is 9x more likely, increased risk in childbearing age, sun exposure exacerabates systemic disease
Antinulcear Antiboides
hallmark of abnormala b in SLE, >95% of SLE have ANA. Ab directed to multiple nuclear antignes
ANA -dsDNA
renal disease
ANA anti-histone
SLE and drug induced lupus
Ab to Non-DNA, non Histone
SSA, SSB, Smith, RNP
SLE diagnostic criterai
4/11: Malar rash, discoid rash, photo sensitivity, oral ulcer, Arthritis, serositis, renal invomvement, CNS - seizures, psychosis, hematologic disease, immunologic disorders, ANA
SLE pathophysiolgy
1) Type III specific antibodies mediated to cause HM, neurophenia, thrombopenia, anti phospholipid ab to block prothrombin activation of clotting. Immune complex form with anti-dsDNA and DNA immune complex that can cause the lump and bumpy IF.
Vasculitis - basic definition
inflammation of vessel
Pathology of vasculitis
varying degress of lymphs, monocytes, histiocytes, eosinophils, PMNs. Granulmonas or giant cells form in some types
large vessels: disruption of elastic lamina + intimal thickening
small vessels: fibroid necrosis (leukocutclastic vasulitis)
large artery vasculitis
Takayasus (claudication of upper extremities + CNS), Giant Cell (temporal artery + headache)
Medium Artey vasculitis
Classic polyartheritis nodes (skin + joint + peripheral nerves); Kawasaki (acute fever in infants, rash, coronary vasculitis)
small artery vasculitis
Wegener’s granulomatosis (ANCA+, respiratory), microscopic pohylangitis (pulmonary hemorrahge + glomerulonephritis), churg-strauss syndrome (asthma+eos)
Arteriole/capillary venule vasculitis
Cryoglobinemia (RF ab and Hep C ab), Cutaneous leukoclastic vasculitis (palpablr purpuric lesions + althralgia), Henoch-schonlein purpura (palpable purpra + abdominal pian + IgA)
Major pathophysiology of Vasculitis - one word
immune complexes
detailed pathophys of vasculitis
inflammation —> platelet activating factors —> increased vascular permeability —> IC deposition; papable purpura.
ANCAS. anti-endothelial ab; T cell mediated endothelial injury,
T cell dependent mediated endothelial cell injury
HLA-DR4 in giant cell arthritis, suggests antigen driven vascular inflammation
Source of immune complexes in vasculitis
Drugs, bugs, CT disease, malignancy
ANCA
antinuetrophil cytoplasmic antibodies in vasculitis; amplifies inflammatory response - not the cause.
c-ANCA
cytoplasmic ANCA, acts on proteinase-3 in primary granules of PMNs; associated with GPA
p-ANCA
perinuclear, acts on MPO in primary granules of PMNs associated with MPA
treatment of vasculitis
remove inciting agent, steroids, plasmapheresis, rituximab
Polymyositis and Dermatomyositis
Inflammatory myopathies with muscle weakness, low endurance, idiopathic, but may overlap with CTDs or neoplastic disease. DM has skin rashes - Guttron’s papules, heliotrope rash, V sign, shawl-sign, mechanics hands, periungual changes/erythema
Systemic effects of PM and DM
GI dysphagia, pulmonary fibrosis, mycocarditis, Ranaud’s phenomenon, Anti-synthetase
Anti-synthetase syndrome
PM or DM presenting with **instertitial lung disease, Fever, arthritis, mechanics hands, raynaud’s phenomenon.
Anti-synthetase antibodies
anti-aminoacyl-tRNA synthetase in cyto,, Anti-Jo-1 = anti histadyl-tRNA synthetase; not pathologic of myotoxic
PM - lab finding
distribution of inflammatory CD8 cells surrounding and invading muscle fibers
DM
Perivascular and perifascicular inflammation of CD4 cells; complement mediated, vasulopathy
pathophysiology of DM/PM
CTL directly attacks muscles
Immune complex damage skin
MHC class I overexertion on myocytes —> ER stress response and NFkB production
Viral infections
Etiology of PM and DM
Virus! Flu and HIV —> viral particles are detected, but not live virus.; DM microarray of mRNA shows interferon responsive pathways
Juvenile DM
increase ab to coxackie B
Seasonal DM
Anti-Jo1 ab in the spring
Treatment of DM and PM
Corticosteroids, immunosuppressives, PT
Musculocutaneous bleeds are a sign of…
primary hemostasis - disorder of platelet of vWF
Soft tissue or joint bleeds are a sign of…
secondary hemostasis - coagulation disorder
aPTT
tests the procoagulant activity of intrinsic pathway most often F XI, VIII, IX; NOT VII.
PT
tests the procoagulant activity of the extrinsic pathway and common pathway - sensitive to II, VII, V, X, Vit K, liver disease
TT
tests procoagulant activity of fibrinogen and affect of heparin and fibrin split. Detects heparin contamination and fibrinogen def/dysfunction.
PFA-100
standardized bleeding time test; Collage/Epi and Collagen/ADP;
Abnormal Epi and normal ADP = aspirin effect
Both abnormal: platelet function effect.
Ristocetin
chemical added to blood to test the activity of vWF binding to GP1b
vWF Disease - mechanism
qualitative platelet disorder due mut/under production of vWF —> decreased adhesion and unstable VIII
vWF
binds to subendothelial collagen and GP1b receptor on platelets for adhesion! stabilizes Factor VIII
GP1b
receptor on platelets that binds to vWF for adhesion
GPIIb/IIIa
exposed on surface of platelets with ADP release from dense granules, used as linkage for platelet aggregation
Epidemiology of vWF disease
AD, but can be acquired by autoab
Clinical signs of vWF disease
mild mucosal and skin bleeding - GI bleed, menorrhagia, NO joint or mucosal bleeds.
Types of vWF
Type 1 = partial quantitative deficiency, type 2: qualitative def type 3: near complete absence
Diagnostic lab tests of vWF disease
Normal PT, Long PTT, decrased vWF antigen, decreased F VIII, abnormal ristecetin
Treatment of vWF
DDAVP desmopressin - arginine vasopressin to enhance release of vWF from endothelial stores, or humane P (vWF and Factor VIII)
Bernard-Soulier Syndrome
Qualitative platelet disorder due to GP1b mutation to decrease adhesion; AR; unaffected PT or PTT
Gray Platelet syndrome
qualitative platelet disorder due to reduced/absent alpha granules, AR
Afibrogenemia
qualitative platelet disorder due to lack of fibrinogen —> no platelet aggregation due to lack of GPIIb/IIIa-fibrinogen binding and no GPIIb/IIIa cross linking; AR; has both mucosal and deep muscle bleeds; prolonged PT and PTT
Ganzman Thrombasthenia
qualitataive platelet disorder, defective/low GPIIb/IIIa leads to decreased aggregation; AR, PTT and pT are unaffected.
Abciximab
GPIIb-IIIa antagonists
Thrombocyopenia
low platelet count due to decreased production, increased destruction, sequestration
Decreased platelet production
BM disorders, aplastic anemia, MDS, leukemia, TB, B12/Folate def, viral infection
Increased platelet destruction
ITP, autoimmune, DIC, TTP, HUS