Revision Lecture Flashcards
List the key features of rheumatoid arthritis
5
Morning stiffness in and around joints Symmetrical polyarthritis typically involving the small joints of the hand and/or wrists Subcutaneous nodules Rheumatoid factor Joint erosions on radiographs
Define rheumatoid factor
Antibodies that recognize the Fc portion of IgG as their target antigen
typically IgM antibodies i.e. IgM anti-IgG antibody !
What substance makes synovial fluid viscous?
Hyaluronic acid
a non-sulphated glycosaminoglycan
Describe the synovium and its contents: 4
Lining, 1-3 cells deep
Type A synoviocytes: macrophage-like phagocytic
Type B synoviocytes:
fibroblast-like
produce hyaluronate
Collagen is type I
Content of synovial fluid?
Hyaluronate-rich viscous fluid
Define Reactive Arthritis
Sterile inflammatory synovitis following an infection whose extra-articular manifestations may include:
Enthesopathy
Skin inflammation (circinate balanitis, keratoderma blennorrhagicum)
Eye inflammation (conjunctivitis)
List two infections associated with Reactive Arthritis
Urogenital infections
E.g. Chlamydia trachomatis
Enterogenic infections
E.g. Salmonella, Shigella, Campylobacter infections
Reactive arthritis may be first manifestation of HIV or hepatitis C infection
Define and give two examples of an enthesopathy
Inflammation where a ligament, tendon, fascia or capsule insert into bone. Examples include:
Achilles tendonitis (painful heel) inflammation at insertion of Achilles tendon into calcaneum
Plantar fasciitis (painful feet) inflammation at insertion of plantar fascia
Dactylitis (swollen digits)
inflammation at insertion of capsule and ligaments in digits
Spondylitis (spinal inflammation) in Ankylosing Spondylitis
inflammation where the outer part (annulus fibrosis) of the inter-vertebral disc inserts into the vertebral body
Rheumatoid arthritis:
Sex ratio Age Arthritis type Enthesopathy Spondylitis Urethritis Skin Involvement Rheumatoid factor HLA-Association
Sex ratio - F>M Age - All ages Arthritis type - Symmetrical, polyarticular, small and large joints Enthesopathy - No Spondylitis - No except for the AA joint in cervical spine Urethritis - No Skin Involvement - subcutaneous nodule Rheumatoid factor - Yes HLA-Association - HLA-DR4
Reactive rheumatoid arthritis:
Sex ratio Age Arthritis type Enthesopathy Spondylitis Urethritis Skin Involvement Rheumatoid factor HLA-Association
Sex ratio - M>F Age - 20-40 years Arthritis type - Assymetrical, oligoarticular, large joints Enthesopathy - YES Spondylitis - YES Urethritis - YES Skin Involvement - K. Blennorhagicum Rheumatoid factor - No HLA-Association - HLA-B27
In a single statement summarise the key pathological finding in osteoarthritis
Irreversible loss of articular cartilage
Pathological changes in OA
3
focal areas of damage to articular cartilage
new bone formation at the joint margins (osteophytosis)
changes in the subchondral bone (sclerosis)
Define (i) proteoglycan and (ii) glycosaminoglycan and give one example of each
glycoproteins containing sulphated glycosaminoglycan chains e.g.
Aggrecan
repeating polymers of disaccharides e.g.
Chondroitin sulphate
disaccharides are: glucuronic acid and N-acetyl galactosamine
Keratan sulphate
disaccharides are: galactose and N-acetyl glucosamine
Hyaluronic acid (= hyaluronate)
disaccharides are: glucuronic acid and N-acetyl glucosamine
What is the major (i) collagen and (ii) proteoglycan found in articular cartilage?
Type II collagen
(aide memoire – two T’s in articular cartilage = type two collagen, Bone has one in it so = type one collagen)
Aggrecan
Rheumatoid arthritis:
Joint space narrowing present? Subchondral sclerosis present? Osteophytes present? Osteopenia present? Bony erosions present?
Joint space narrowing - Yes Subchondral sclerosis - No Osteophytes - No Osteopenia - Yes Bony erosions - Yes
Osteoarthritis:
Joint space narrowing present? Subchondral sclerosis present? Osteophytes present? Osteopenia present? Bony erosions present?
Joint space narrowing - Yes Subchondral sclerosis - Yes Osteophytes - Yes Osteopenia - No Bony erosions - No
List the major HLA association for each of the following diseases
Ankylosing Spondylitis & Reactive Arthritis
SLE
Rheumatoid arthritis
Ankylosing Spondylitis & Reactive Arthritis HLA-B27
SLE HLA-DR3
Rheumatoid arthritis HLA-DR4
Summarise the composition of bone
Bone is comprised of protein matrix (osteoid) and mineral (hydroxyapatite)
Osteoclasts resorb bone, osteoblasts form bone
Define Osteoporosis
Predisposition to skeletal fractures resulting from reduction in regional or total bone mass
Bone chemistry is normal (serum calcium, phosphate, PTH, alkaline phosphatase)
Osteoporosis is assessed by ‘dual energy X-ray absorptiometry’ – DEXA scanning
Osteoporosis is defined by a measurement derived from the DEXA scan - T-score
Define Osteomalacia
Osteomalacia literally means ‘soft bones’ and is defined as impaired mineralisation in mature bones. Rickets is impaired mineralisation in immature bones
Most frequently due to inadequate extracellular fluid concentration of phosphate and/or calcium
Causes include:
Vitamin D deficiency (can measure vitamin D level so easy to determine)
Abnormal vitamin D metabolism e.g. liver or kidney disease
Hypophosphataemia (may be due to renal phosphate loss which can be determined by measuring urinary phosphate levels)
Associated with:
Low or normal serum calcium
Low phosphate
Secondary hyperparathyroidism i.e. high PTH and high serum alkaline phosphatase
Define Paget’s disease
Disorder of bone remodelling of unknown cause where there is increased bone resorption followed by increased bone formation. This results in disorganised mosaic pattern of woven and lamellar bone
Bone chemistry shows high alkaline phosphatase
Paget’s is associated with increased cortical bone thickness on radiographs
The abnormal bone causes:
Pain
Bone deformity and sometimes fracture
Biochemical changes to following in osteoporosis:
Serum Ca Serum PO4 Serum Alk Pho Bone formation Bone resorption
Serum Ca - N Serum PO4 - N Serum Alk Pho - N Bone formation - Up or N Bone resorption - Up Up
Biochemical changes to following in osteomalacia:
Serum Ca Serum PO4 Serum Alk Pho Bone formation Bone resorption
Serum Ca - N or down Serum PO4 - down Serum Alk Pho - Up Bone formation - N/a Bone resorption - N/a
Biochemical changes to following in Pagets:
Serum Ca Serum PO4 Serum Alk Pho Bone formation Bone resorption
Serum Ca - N Serum PO4 - N Serum Alk Pho - up up up Bone formation - up up Bone resorption - N/a
Biochemical changes to following in Primary HPT:
Serum Ca Serum PO4 Serum Alk Pho Bone formation Bone resorption
Serum Ca - Up Serum PO4 - Down Serum Alk Pho - N or up Bone formation - N/a Bone resorption - up up
Biochemical changes to following in renal osteodystrophy:
Serum Ca Serum PO4 Serum Alk Pho Bone formation Bone resorption
Serum Ca - Serum PO4 - Serum Alk Pho - up Bone formation - up Bone resorption -
Biochemical changes to following in bone metastases:
Serum Ca Serum PO4 Serum Alk Pho Bone formation Bone resorption
Serum Ca - up Serum PO4 - up Serum Alk Pho - up Bone formation - N/a Bone resorption - up
radiological findings in hyperparathyroidism? (6)
SUB-PERIOSTEAL RESORPTION
BROWN TUMOURS
CHONDROCALCINOSIS
OSTEOSCLEROSIS
‘Salt and Pepper’ skull
‘Rugger jersey’ spine
