Pathophysiology Flashcards
(117 cards)
osteoarthritis
older
NO inflammation
DEGENERATIVE: erosion of articular cartilage, osteophytes, subchondral sclerosis, alterations of the synovial membrane (can thicken) and joint capsule, eburnation (progressive thickening), Herberden nodes (increased activity at pericondrium), loose bodies/ joint mice (fragments of cartilage), cyst formation
Dx: clinical, xray, normal labs
Sx: pain gets worse with use/during the day, morning stiffness
increases mortality
risk factors for osteoarthritis
- age
- joint location
- obesity
- genetics
- joint malalignment
- trauma
- gender: female
- neuromuscular dysfunction
- metabolic disorders
morphologic changes in osteoarthritis: early vs. late
early: articular cartilage surface irregularity, superficial clefts, altered proteoglycan distribution
late: deepened clefts, increase surface irregularities, articular cartilage ulceration, exposed underlying bone, chondrocytes from clusters to self-repair, osteophytes
MMP
matrix metalloproteinases that degrade proteoglycans and collagen
OSTEOARTHRITIS
Most commonly affected joints in osteoarthritis
ASYMMETRIC: more LOWER
hands (DIPS and PIPS), hips, knees, spine, feet
Pseudogout associations
- hemochromatosis
- hyperPTH
- hypothyroidism
- hypophosphatasia
- hypomagnesemia
- neuropathic joints
- trauma
- age, heredity
First line nonopioid analgesic therapy for osteoarthritis
acetaminophen
max safe dose: 4g/day
types of intra-articular therapy for osteoarthritis
- steroids
2. hyaluronate injections
intra-articular steroids
2nd line Tx
up to every 3 mo (knee most often)
Tx: osteoarthritis pain
AE with frequent injections: infection, worsening DM, or CHF
hyaluronate injections
Tx: osteoarthritis symptom relief (improves function)
expensive
no long-term benefit
limited to KNEE
Surgical Tx for osteoarthritis
3rd line Tx
- arthroscopy (may reveal unsuspected focal abnormalities, results in tidal lavage, expensive, complications)
- osteotomy (delay need for total joint replacement)
- total joint replacement (when pain severe and function significantly limited)
anti-CCP (cyclic citrullinated peptide)
most sensitive and specific for RA (can be found in unaffected relatives)
produced by synovial tissue B cells
activate complement pathways, IgE ACPAs cause basophil/ mast cell degranulation
prognosis: more aggressive, accelerated atherosclerosis, risk for ischemic heart disease
HLA-B27
seronegative spondylarthropathies
MHC class I molecule that presents antigens to CD8 T cells
in psoriasis or IBD: indicates likely to develop axial (spinal) arthropathy
ANA
Ab against nucleus
most sensitive SLE: no ANA, no lupus
also: RA, scleroderma, Hashimoto’s, IPF
anti-dsDNA
high specificity for SLE
associated with: NEPHRITIS
anti-RNApol3Ab
HTN renal crisis in diffuse systemic sclerosis
anti-centromere
limited cutaneous sclerosis
anti-Jo1
Ab against histdyl-tRNA synthetase
inflammatory myopathy
associated with: arthritis in myopathies
anti-Mi-2
dermatomyositis
rheumatoid arthritis (RA)
30s-50s female
INFLAMMATORY, SYSTEMIC
SYMMETRIC arthritis
increases mortality
genetic (additive/multiplicative) and environmental
elevated: ESR, CRP
Ab: anti-CCP, RF
Sx: fatigue, anorexia, weight loss, weakness, general aching and stiffness, low fever
joint: morning stiffness at least 30 min, swelling, warmth, erythema
synovial fluid: exudative yellow fluid, WBC elevated, reduced viscosity
onset: one or scattered joints, often large peripheral joints (knee)
immune complexes, lysosomes, ILs, FBGF, mononuclear cells infiltrating synovial membrane (acute: PMN)
HLA-DR4
30% RA risk
binds and presents antigen to T cell
DR4 shared epitope and T cell receptor interact
selection of auto reactive T cells in thymus
PTPN22
5% RA risk
TNFAIP3
5% RA risk
STAT4
5% RA risk