RHEUMATOLOGY REVIEW Flashcards
Degeneration of articular cartilage with hypertrophy of contiguous bone:
DX: joint space loss, subchondral cysts, sclerosis, osteophytes
Osteoarthritis (OA)
OA: Predisposing Factors (primary)
Age Obesity Occupational risks: Miners: OA hips, knees, shoulders Weavers: OA hands Trauma
Osteoarthritis (OA) Joint Involvement:
DIP (Heberden’s), PIP (Bouchard’s), 1st CMC
Hips and knees
Spine: cervical and lumbar
First MTP
Osteoarthritis (OA) DX:
joint space loss, subchondral cysts, sclerosis, osteophytes
OA: Predisposing Factors secondary
Secondary OA:
Inflammatory
Metabolic: hemochromatosis, Wilson’s disease, ochronosis
Sports: in general, no increased risk; exercise may be protective
**Sports: in general, no increased risk for OA; exercise may be _______
protective
Collagen: predominantly type II
Proteoglycans (chondroitin and keratin sulfate) linked to hyaluronic acid
Matrix proteins
~Metalloproteinases (MMPs): collagenase, gelatinase, stromelysin
~Tissue inhibitors of metalloproteinases (TIMPS)
Chondrocytes
Water
Cartilage components (avascular, no nerves)
In OA, the big problem is
cartilage tries to repair itself unsuccessfully
Cartilage in early Osteoarthritis
↑ inc chondrocytes
↑ inc metalloproteinases
↑ inc water content
dec TIMP
dec proteoglycan
cartilage changes from a spounge into a dish rag
OA Characteristics
Lacks systemic features
Synovial fluid: noninflammatory, type I fluid (200-2000 WBC/mm3)
__________ stimulates MMP production, PGE2, nitric oxide (NO), IL-6 in OA
Interleukin-1:
___________: increases MMP production, inhibits proteoglycan synthesis, induces chondrocyte apoptosis in OA
Nitric oxide
__________: ↑ production and activation of MMPs in OA
Prostaglandins
Complement activation Adipokines Interleukin-1: Nitric oxide Prostaglandins
present in?
OA
Adipokines
fat cells may produce IL-6
OA: Knees
Joint space loss
Sclerosis
Subchondral cysts
Osteophytes
A systemic, inflammatory, autoimmune disorder of unknown etiology that results predominantly in a peripheral, symmetric synovitis which can result in cartilage and bone destruction
Joint involvement:
Bilateral, symmetric - small joints hands + feet sparing the DIPs
Medium and large joints can be involved
X-rays: marginal joint erosions and deformities
Rheumatoid Arthritis (RA)
Rheumatoid Arthritis (RA): A systemic, inflammatory, autoimmune disorder of unknown etiology that results predominantly in a peripheral, ________________ which can result in cartilage and bone destruction
symmetric synovitis
Rheumatoid Arthritis (RA) Joint involvement:
Bilateral, symmetric - small joints hands + feet sparing the DIPs
Medium and large joints can be involved
Rheumatoid Arthritis (RA) Disease susceptibility and severity associated with shared epitope (QKRAA; in antigen binding groove) in subtypes of _____________ other genes are also involved
**HLA-DR4 and HLA-DR1
Antibody directed against the Fc portion of IgG; RF usually IgM, can be IgG or IgA
RF present in 85% of patients with RA
Not specific for RA or CTDs
Produced locally in the synovial tissue
RF-IgG immune complexes are pathogenic
Rheumatoid factor (RF):
RF-IgG immune complexes are _______
pathogenic
Rheumatoid factor (RF): Can cause vasculitis or nodules
Rheumatoid factor (RF) ispresent in
many disease ex ra sjordons sle
Anti-CCP
Anti-Cyclic Citrullinated Peptide Antibodies
RF not very specific for RA
reactive with synthetic peptides containing the unusual amino acid citrulline (modified arginine residue) are specifically present in the sera of RA patients:
Anti-CCP abs occur more frequently in individuals with the shared epitope; citrullination of peptides enhances binding
Inflammed tissue of macs, t cells, plasma cells
Pannus
in RA
Synovial fluid major cell in RA?
neutrophils
Production of metalloproteinases and other effector molecules
Migration of polymorphonuclear cells
Erosion of ____________ in RA
bone and cartilage
CD4+ memory T cells related to RA
modulation and amplification of local immune response through antigen recognition (query altered proteoglycans or collagen; citrullinated peptides)
unknown antigen sparks RA, by RA start disease is cleared but RA goes on
Extra-articular manifestations in RA
RF-IgG immune complex-induced vasculitis
Rheumatoid nodule formation in tissues/organs
The result of tissue deposition of monosodium urate (MSU) crystals due to hyperuricemia (MSU supersaturation of extracellular fluids)
Gout
Gout Joint Involvement:
1st MTP (podagra)GRaet Toe
Cool, peripheral joints of lower and upper extremities
Gout Hyperuricemia: over-production or under-excretion of uric acid; _______ (90%) most cases
underexcretors
Uric acid is a product of ______ metabolism
purine
Humans lack ______ which oxidizes uric acid into allantoin (more soluble compound)
uricase
___________of uric acid (X-linked):
PRPP synthetase overactivity
HGPRT deficiency (complete: Lesch-Nyhan)
Overproduction
Crystal arthritis is ________________ and crystal identification by polarized microscopy (MSU crystals: needle-shaped, negatively birefringent)
diagnosed by arthrocentesis
X-linked inborn errors of Gout
inc PRPP synthetase
dec HGPRT
_______ inhibited by allopurinol and febuxostat, can treat gout
Xanthine oxidase
Overproduction of uric acid (X-linked):
__________overactivity
HGPRT deficiency (complete: Lesch-Nyhan)
PRPP synthetase
IgG-coating promotes phagocytosis by PMNs
IgG: not specific anti-crystal antibodies
(Proteins coating the crystals modulate the cellular response)
These are NOT ANTI CRYSTAL AB
Apolipoprotein B-coating____________phagocytosis
inhibits
Proteins coating the crystals modulate the cellular response
Overproduction of uric acid (X-linked):
PRPP synthetase overactivity
__________(complete: Lesch-Nyhan)
HGPRT deficiency
___________ includes ligamentous-, tendinous-, fibrous-osseous junctions
Enthesitis
Seronegative Spondyloarthropathies
Phagocytosis of crystals ___________concentration
decrease
Local heat of inflammation __________MSU solubility
increase
Calcium Pyrophosphate Dihydrate Deposition Disease
Abnormal pyrophosphate (PPi) metabolism
“pseudogout”
PPi precipitates with calcium forming CPPD crystals in mid-zonal cartilage layers. Crystal release into the joint space. On xray?
Chondrocalcinosis
CPPD crystals:
rhomboid, positively birefringent
Seronegative Spondyloarthropathies hallmark
SI joints (sacroiliitis); morning (am) stiffness
Seronegative Spondyloarthropathies affect
Enthesitis:
ligamentous-, tendinous-, fibrous-osseous junctions
Seronegative Spondyloarthropathies Synovium:
Synovium: increased expression of TNF
HLA-B27 and Ankylosing Spondylitis (AS) Chance of developing AS
2% if HLA-B27 positive
20% if HLA-B27 positive with a first-degree relative with AS
HLA B27 + has a ___ chance of AS
2%
HLA B27 + w/ AS FDR has a ___ chance of AS
20%
Reactive Arthritis
Asymmetric, oligoarticular, lower ext arthritis
Dactylitis are?
sausage digits?
Reactive Arthritis Unfolded protein hypothesis: ER stress response
in ER HLA b27 misfolds and cannot be released
builds up in ER
stress response to cell
ER stress makes Il-23–> Th17 –> inflammation
Reiter’s syndrome: clinical triad of conjunctivitis, urethritis, arthritis
Former name of Reactive Arthritis
Reiter’s syndrome: clinical triad of ___________
conjunctivitis, urethritis, arthritis
Systemic Lupus Erythematosus (SLE)
A chronic, systemic autoimmune disease which affects multiple organ systems including the skin, joints, serosal surfaces, lungs, kidneys, CNS, and hematologic system
SLE - Fundamental defect is the ________________, resulting in an autoimmune process; T cell and B cell process
misdirected recognition of self as foreign
SLE is a?
T AND B CELL PROCESS
SLE Antibody responses toward autoantigens are antigen-driven and require ____________
CD4+ T cells
SLE Loss of T cell tolerance permitting autoreactive B cell stimulation: ? central or peripheral abnormality in_____________ lymphocyte deletion or anergy
self-reactive
Association with HLA-DR3 and C4A null allele (greatest risk)
SLE
SLE Association with HLA-DR3 and _________ (greatest risk)
C4A null allele
SLE- Loss of T cell tolerance permitting ___________: ? central or peripheral abnormality in self-reactive lymphocyte deletion or anergy
autoreactive B cell stimulation
Antinuclear Antibodies (ANA)
SLE: > 95% patients have + ANAs
Not specific for SLE
Antibodies are directed to multiple nuclear antigens
CD4 directed
Systemic Lupus Erythematosus (SLE)
Genetics (polygenic):
C4A null allele (greatest risk)
ANA specific for SLE?
NOPE
Anti-dsDNA antibodies:
renal disease
Anti-histone antibodies:
SLE and drug-induced lupus
Anti-phospholipid antibodies: block prothrombin activation in the clotting cascade; associated with increased _______ ? neutralize anticoagulant effect of 2 GP1; do not cause a vasculitis
clotting
Specific antibody-mediated disease (Type II):
Inflammation within or through the vessel wall resulting in damage to vessel integrity/flow
Vasculitis
Vasculitis Pathology
Varying degree of infiltrating lymphs, monocytes, histiocytes, eosinophils, and PMNs
Granulomas and/or giant cells in vessel wall in some types of vasculitis
Fibrinoid necrosis of vessel wall secondary to immune complex deposition
Focal and segmental nature of vascular lesions common to all types of vasculitis
Vasculitis Pathology
Immune complexes: inflamm→ PAFs→ ↑vascular permeability→ IC deposition; __________
palpable purpura
Vasculitis Pathology- Pathophysiology:
Immune complexes: inflamm→ PAFs→ ↑___________→ IC deposition; palpable purpura
vascular permeability
Vasculitis Pathology- Pathophysiology:
T cell dependent-mediated endothelial cell injury: (HLA-DR4 and giant cell arteritis; suggests ___________ vascular inflammation)
antigen-driven
HLADR4 in Vasculitis is not related to?
RA HLADR4
Vasculitis- Sources of antigen for immune complexes:
Drugs
Bugs: infectious agents
Connective tissue disease: autoimmune process
Malignancy
ANCA Vasculitis
Antineutrophil Cytoplasmic Antibodies. Seperates small Vasculitis
*Cytoplasmic ANCA (c-ANCA):
Proteinase-3 (PR3) in primary granules of PMNs
Associated with generalized GPA (Wegener’s)
*Perinuclear ANCA (p-ANCA):
Myeloperoxidase (MPO) in primary granules of PMNs
Associated with microscopic polyangiitis (MPA)
Inflammatory myopathies are characterized by: Muscle weakness (proximal) and low endurance Usually idiopathic but may occur in association with neoplastic diseases or in “overlap” with CTDs
Polymyositis / Dermatomyositis (PM/DM)
-DM presents with typical skin rashes:
Gottron’s papules Heliotrope rash V-sign and shawl-sign Mechanic’s hands Periungual changes/erythema
*Anti-synthetase Syndrome
PM or DM presenting with:
Interstitial lung disease (ILD): 60%*****
Anti-synthetase antibodies:
Anti-aminoacyl-tRNA synthetases (cytoplasm)
Anti-Jo-1 = anti-histadyl-tRNA synthetase
Not pathologic or myotoxic antibodies
Anti-synthetase antibodies:
Anti-aminoacyl-tRNA synthetases (cytoplasm)
Anti-Jo-1 = ______________
Not pathologic or myotoxic antibodies
anti-histadyl-tRNA synthetase (antiJo1)
Not pathologic or myotoxic antibodies- IT IS A MARKER OF DISEASE
Endomysial distribution of inflammatory cells (CD8+ T cells) surrounding and invading muscle fibers
Polymyositis
Perivascular (CD4+ T cells) and perifascicular inflammatory infiltrate
Dermatomyositis
Around vasical
Polymyositis / Dermatomyositis Evidence suggesting a _________ etiology:
viral
Viral particles by EM and viral RNA detected in muscle from PM/DM patients. NO live virus has been cultured from muscle
Osteoarthritis (OA) Joint Involvement:
Joint Involvement: DIP (Heberden’s), PIP (Bouchard’s), 1st CMC Hips and knees Spine: cervical and lumbar First MTP