MSK; Lecture 7, 8 - GALS screen and Systemic Lupus erythmatosus; Revision Lecture Flashcards
What is the family of AI diseases that SLE comes from?
Rheumatoid arthritis
- Systemic lupus erythematosus
- Systemic sclerosis
- Polymyositis
- Dermatomyositis
- Sjögren’s syndrome
What is SLE?
1M:9F, presentation in 15-40y; increased in afro-carib, asian and chinese; prinicpally affects joints and skin, lung, kidneys and haematology
What are the genetic associations of SLE?
Multiple genes implicated, complement deficiency (C1q and C3), Fc receptors, IRF5, CTLA4, MHCII HLA genes
What are the presenting features of SLE?
What are the features that SLE presents with in the SLE-ACR criteria?
4 or more criteria of these presentations.
Rash can affect the dermis, leading to depigmentation, can look like acne but isn’t itchy or painful.
Patients feel very unwell
What is the pathogenesis of SLE?
Immune-complex mediated disease -> deposition of immune-complexes in the tissues fire off the disease, with the complements.
Severity increases with every attack
What biological processes differ in SLE?
How are the autoantibodies formed?
How can you diagnose SLE with ANA?
HOWEVER NOT a diagnostic test - can use it to go in the right direction.
- Homogenous - Abs to DNA;
- Speckled - Abs to Ro, La, Sm, RNP;
- nucleolar - topoisomerase - scleroderma;
- centromere - limited cutaneous scleroderma
What are the different lab diagnostic tests that can be carried out for SLE?
How can you assess disease severity of SLE?
How can you work out if the SLE is becoming more active?
SLE is a relapsing-remitting disease
What are the 3 groups of SLE patients when deciding how to treat?
x
How would you treat mild SLE?
How would you treat moderate SLE?
How do you treat severe SLE?
Cyclophosphamide only used if SEVERE organ involvement;
Mycophenolate is teratogenic but has no effect on fertility
What is the prognosis and survival of SLE?
15y survival = no nephritis 85%, nephritis 60%; prognosis is worse if black, male and low socio-economic status. Need to engage with treatment as it can be very tiring to be in the hospital for months taking drugs and other things
What is the biomodal mortality pattern of SLE?
Early peak in mortality in SLE and then there is a later peak as well -> early death is due to renal failure, CNS disease, infection; late death due to MI and stroke
What are the signs on a blood film for SLE?
- Schistocytes (microangiopathic haemolytic anaemia),
- spherocytes,
- tear drop cells,
- few leukocytes and platelets;
- anisocytosis,
- poikilocytosis,
- fibrin strands,
- thrombocytopaenia
What are the signs on a renal biopsy for SLE?
- Proliferative, crescentic glomerulonephritis;
- Hypercellular, messangial proliferation,
- crescent development (inflammatory cells that have migrated into the glomerulus)
What does GALS stand for?
Gait, Arms, legs, spine
What is arthritis?
Refers to definite inflammation of the joint
What is arthralgia?
Pain within a joint without demonstrable inflammation by physical examination
What is dislocation?
Articular surfaces are displaced and no longer in contact
What is subluxation?
Partial dislocation
What is a varus deformity?
Lower limb deformity whereby the distal part of the limb is directed towards the midline
What is a valgus deformity?
Lower limb deformity whereby distal part of limb is directed away from midline
How do you test for gait in GALS?
Observe patient walking, turning and walking back look for: smoothness and symmetry of leg, pelvis and arm movements normal stride length ability to turn quickly
How do you test the spine in GALS?
How do you test the arms in GALS?
How do you test the legs in GALS?
x
How do you test the abnormal joints ID’d in GALS?
- Inspection: swelling, redness, deformity
- Palpation: warmth, crepitus, tenderness
- Movement: active, passive, against resistance
- Function: loss of function
What are the signs of inflammation?
Swelling (tumor) Warmth (calor) Erythema (rubor) Tenderness (dolor) Loss of function (functio laesa)
What is gout?
A disease in which tissue deposition of monosodium urate (MSU) crystals occurs as a result of hyperuricaemia and leads to one or more of the following: Gouty arthritis Tophi (aggregated deposits of MSU in tissue); Abrupt onset Extremely painful Joint red, warm, swollen and tender Resolves spontaneously over 3-10 days. Gouty arthritis commonly affects the metatarsophalangeal joint of the big toe (‘1st MTP joint’)
What are tophi?
Deposition of crystalline uric acid outside of the joint
How does the site of swelling and tissues involved indicate different diseases in GALS exams?
What are enthesopathy?
Pathology at the enthesis i.e. the site where ligament or tendon inserts into bone examples include: plantar fasciitis Achilles tendinitis.
What are the signs of irreversible joint damage?
Joint deformity malalignment of two articulating bones Crepitus audible and palpable sensation resulting from movement of one roughened surface on another classic feature of osteoarthritis e.g. patello-femoral crepitus on flexing the knee Loss of joint range or abnormal movement
How is ankylosing spondylitis a good example of irreversible joint damage?
What are the signs of mechanical defects in the joint?
May due to inflammation, degenerative arthritis or trauma and identified by painful restriction of motion in absence of features of inflammation e.g. knee ‘locking’ due to meniscal tear or bone fragment instability e.g. side-to-side movement of tibia on femur due to ruptured collateral knee ligaments
How does the number of joints involved change the diagnosis in GALS?
How can you differentiate between rheumatoid arthritis, osteoarthritis and polyarticular gout using the joints that are commonly affected/spared?
What are other features of diagnostic importance?
Subcut nodules in rheumatoid arthritis, tophi for gout, malar rash for SLE
What are the general questions needed to be asked for a locomotor examination?
Are any joints abnormal?, Nature of joint abnormality, extent of joint involvement, any other features of diagnostic importance
How would synovial fluid look like after an effusion in normal, non-inflammatory, inflammatory and infection disease?
When would you take a synovial fluid effusion?
What are the types of crystals - shape and bioefringence that can occur in gout and pseudogout?
What do you do if a patient comes in with an acutely painful right knee?
What do you do if a patient comes in with swelling behind the elbow?
What are the key features of rheumatoid arthritis?
Morning stiffness in and around joints; symmetrical polyarthritis (small joints of hand and wrist), subcut nodules, rheumatoid factor and joint erosions on radiograph
Define rheumatoid factor?
Ab that recognises the Fc portion of IgG as their target Ag -> typically IgM Ab; i.e. IgM anti-IgG Ab
What substance makes synovial fluid viscous?
Hyaluronic acid
Define reactive arthritis?
Sterile inflammation synovitis following an infection whose extra-articular manifestations = enthesopathy, skin inflammation (circinate balanitis and K blennorhagicum) and eye inflammation (conjuctivitis)
What are 2 infections associated with Reactive arthritis?
Urogenital infections (chlamidiya), entergoenic infectons (salmonella, shigella, campylobacter infections); reactive arthritis may be first manifestation of HIV or hep C infection
Define and give 2 examples of enthesopathy?
Inflammation where a ligament, tendon, fascia or capsule insert into bone; Examples = achilles tendonitis, plantar fasciitis, dactylitis and spondylitis in ankylosing spondylitis
Summarise key pathological finding in osteoarthritis?
Irreversible loss of articular cartilage
Define proteoglycan and GAG and give example of each?
Proteoglycan = glycoprotein with sulphated GAG chains; aggrecan GAG = repeating polymers of disaccharides; chondroitin sulphate, keratan sulphate, hyaluronate
What is the major collagen and proteoglycan found in articular cartilage?
Type II collagen and aggrecan is proteoglycan
List the major HLA associations for SLE, AS/Reactive A and Rheumatoid A
AS/Reactive A = HLA -B27; SLE = HLA DR3; Rheumatoid Arthritis = HLA-DR4
Summarise the composition of bone
Bone is composed of protein matrix (osteiod) and hydroxyapatite
What is the definition of osteoporosis?
Predisposition to skeletal fractures resulting from reduction in regional/total bone mass
Define osteomalacia
Impaired mineralisation in mature bones; rickets is in immature bones -> due to inadequate Phosphate or calcium; associated with 2ry HerPTH
Define Paget’s disease
Disorder of bone remodelling of unknown cause where there is increased bone resorption followed by increased bone formation, resulting in disorganised mosaic pattern of woven and lamellar bone
Fill in this table for Rheumatoid arthritis vs reactive arthritis
Fill in the table for radiographic changes in Rheumatoid vs osteoarthritis?
x
Describe the biochemical changes (Ca, P, Alk P, bone formation, bone resorption) in metabolic diseases
Summarise Osteoporosis, osteomalacia, rickets, paget’s disease
What are the radiological findings of hyperparathyroidism - osteitis fibrosis cystica?
Which metabolic bone disorders are part of the renal osteodystrophy family?
2ry and 3ry HerPTH; osteomalacia and soft tissue and vascular calcification
