The Pathophysiology Of Joint Disease Flashcards
What is the prevalence of RA in the population
1%
Characteristics and distinguishing features of RA
Insidious onset
Joint swelling
Early morning stiffness
Dramatic NSAID response is helpful for symptoms
Which joints primarily affected in RA
MCPs, PIPs and wrists
Affects small joints in a symmetrical fashion
Where is the primary site of inflammation in RA
Synovium
Autoimmune response inflammation drives RA
Activation of T cells in RA leads to what..
Cytokines activation via
- direct activation
- indirect = activate macrophages/fibroblasts to then activate cytokines
How can T cells also influence B cell activity
Activate B cells to generate autoantibodies which will target own tissues —> tissue damage over time
Which 3 cytokines involved in RA
TNF alpha
IL-1
IL-6
TNF alpha has paracrine effects, aside from increasing release of other pro-inflammatory mediators how does it affect the following systems:
- 2 = endothelium
- 3 = hepatocytes
- 4 = epidermis
- 5 = synoviocytes
1) increase in adhesion molecules which increases cell infiltration
2) increase in VEGF which results in increased angiogenesis
3) increase in acute phase response which results in increased CRP in serum
4) increased keratinocytes which hyperproliferate leading to skin plaques
5) increased metalloproteinase synthesis which results in articular cartilage degradation
What happens early in disease in RA
S.membrane becomes thickened and inflamed with proliferation of new blood vessels thus promoting an in influx of pro-inflammatory cytokines
What is pannus
Invading layer of inflammatory tissue formed. Can be painful and damages bones and cartilage
At what point does damage from RA become irreversible
Invasion of bone and cartilage into joint space reducing the space and allowing bone erosion to occur
What are effects of chronic systemic inflammation
Early IHD
Sarcopenia
Dementia
Hyper cholesterol anemia
Pain sensitisation
Osteoporosis
Insulin resistance
What are the key considerations in treating RA
Stopping the inflammation
Preventing the damage
Preserve function
1) early diagnosis (stiffness in morning, swelling, squeezing (painful) —> public health campaigns
2) early intensive treatment such as monoclonal antibodies
3) tight control of inflammation by regular assessment and tweaking meds
What is the most common joint disorder that is considered a normal part of ageing
Osteoarthritis
Associated with less inflammation and occurs in weight bearing joints of axial skeleton
What are the risk factors for developing OA
Age —> increases with age. 80% of those above 75 affected
Female sex
Genetic - family Hx
Obesity
Oestrogen deficiency
Occupation
Pre-existing joint abnormality
Past trauma
Cause of pain in OA
Prostaglandins
Synovitis
Cytokines
Subchondral fractures
Periosteal elevation
Muscle spasm
Venous congestion
Bio mechanical effects
Management of OA
Patient education and information access
Pain relief
Optimisation of function
Modification of disease process
Examples of crystal arthritis
Gout (contains Uric acid crystals)
Calcium phosphate disease ( contains calcium pyrophosphate dihydrate CPPD crystals)
Prevalence of gout
1-2% in UK
Men>women
Prevalence increases with age
Co-morbidities associated with gout
Renal impairment (at double the risk of renal stones)
CHD
Metabolic syndrome:
- obesity
- dyslipidaemia
- hypertension
- T2 DM
What are the non-modifiable risk factors for gout
Age
Male
Race
Genetic factors
Impaired renal function
What are the modifiable risk factors for gout
Hyperuricaemia
High purine diet
Alcohol consumption
Obesity
Meds such as diuretics ( increase how much you pee so in blood is more likely to form crystals)
Why do uric acid levels need to be below irate solubility level
Allows uric acid to dissolve and allow excretion from body
What are purine rich foods
Red meat
Seafood
Alcohol
