Rheumatology Flashcards
What disease is this autoantibody found and what does it test for?
RF
- Disease:
- RA 80%
- SS 50%
- SLE 20%
- tests for
- Autoantibodies (IgM>IgG>IgA) directed against Fc domain of IgG
- Present in most seropositive diseases
- Levels correlate with disease severity in RA
- Non-specific
- Present in IE, TB, hepatitis C, silicosis, sarcoidosis
What disease is this autoantibody found and what does it test for?
Anti-CCP
- Disease:
- RA 80%
- Tests for:
- In RA: anti-CCP more specific than RF
- May be useful in early disease and to predict aggressive disease
What disease is this autoantibody found and what does it test for?
ANA
- Disease
- SLE 98%
- Mixed connective tissue disease (MCTD) 95%
- Sjögren’s syndrome 70-90%
- CREST 80%
- Tests for
- Ab against nuclear components (DNA, RNA, histones, centromere)
- Sensitive but not specific for SLE
What disease is this autoantibody found and what does it test for?
Anti-dsDNA
- Disease
- SLE 50-70%
- Tests for:
- Specific for SLE
- Levels correlate with disease activity
What disease is this autoantibody found and what does it test for?
Anti-Sm
- Disease
- SLE <30%
- Test for
- Specific but not sensitive for SLE
What disease is this autoantibody found and what does it test for?
Anti-Ro (SSA)
- Disease
- Sjögrens syndrome 40-95%
- Test for
- Subacute cutaneous SLE and mothers of babies with neonatal SLE 25%
What disease is this autoantibody found and what does it test for?
Anti-La (SSB)
- Disease
- Sjögrens syndrome 40%
- SLE 10%
- test for:
- Usually occurs with anti-Ro
What disease is this autoantibody found and what does it test for?
Antiphospholipid Ab (LAC, ACLA)
- Disease
- Antiphospholipid antibody syndrome (APLA) 100%
- SLE 31-40%
- tests for
- By definition present in APLA
- Only small subset of SLE patients develop clinical syndrome of APLA
- If positive, will often get a false positive VDRL test
What disease is this autoantibody found?
Anti-Histone
- Drug-induced SLE >90%
- Idiopathic SLE >50%
What disease is this autoantibody found?
Anti-RNP
mixed connective tissue disease
What disease is this autoantibody found and what does it test for?
Anti-centromere
- Disease:
- CREST >80%
- tests for:
- Specific for CREST variant of systemic sclerosis
What disease is this autoantibody found?
Anti-topoisomerase I
Diffuse systemic sclerosis 26-76%
What disease is this autoantibody found and what does it test for?
c-ANCA
- Disease
- Active GPA (Wegener’s) >90%
- Tests for:
- Specific and sensitive
What disease is this autoantibody found and what does it test for?
p-ANCA
- Disease
- GPA (Wegener’s) 10%
- Other vasculitis
- Test for:
- Nonspecific and poor sensitivity (found in ulcerative colitis, PAN, microscopic polyangiitis, Churg-Strauss, rapidly progressive glomerulonephritis)
What disease is this autoantibody found and what does it test for?
Anti-Mi-2
- Disease
- dermatomyositis 15-20%
- Tests for:
- Specific but not sensitive (not available in all centers)
What disease is this autoantibody found and what does it test for?
Ab against RBCs, WBCs, or platelets
- Disease
- SLE
- Tests for:
- Perform direct Coomb’s test
- Test Hb, reticulocyte, leukocyte and platelet count, antiplatelet Abs
What is the pathophysiology and some examples of type I (anaphylactic) hypersensitivity?
- Formation of IgE → release of immunologic mediators from basophils/mast cells → diffuse inflammation
- Asthma, allergic reaction
What is the pathophysiology and some examples of type II (cytotoxic) hypersensitivity?
- Formation of Ab → deposit and bind to Ag on cell surface → phagocytosis or lysis of target cell.
- Autoimmune hemolytic anemia, Goodpasture’s syndrome, Graves’ disease, pernicious anemia.
What is the pathophysiology and some examples of type III (immune complex) hypersensitivity?
- Formation of Ag-Ab complexes → activate complement → attract
inflammatory cells and release cytokines. - SLE, PAN, post-streptococcal glomerulonephritis, serum sickness
What is the pathophysiology and some examples of type IV (cell-mediated/delayed) hypersensitivity?
- Release of cytokines by sensitised T-cells and T-cell mediated cytotoxicity
- Contact dermatitis
What are some patterns of joint involvement in disease?
- Symmetrical vs. asymmetrical
- Small vs. large
- Mono vs. oligo (2-4 joints) vs. polyarticular (≥5 joints)
- Axial vs. peripheral
What are the DDx of monoarthritis?
What are the DDx of oligoarhtritis/polyarthritis?
What are the symptoms of inflammatory arthritis vs degernative arthritis?
What are the differences between seropositive vs seronegative rheumatic disease?
Demographics, peripheral arthritis, pelvic/axial disease, enthesitis, extra-articular.
Define osteoarthritis.
progressive deterioration of cartilage and bone due to failed repair of joint damage caused by stresses on the joint
What the primary and secondary causes of osteoarthritis?
- primary (idiopathic)
- most common, unknown etiology
- secondary
- post-traumatic or mechanical
- post-inflammatory (e.g. RA) or post-infectious
- heritable skeletal disorders (e.g. scoliosis)
- endocrine disorders (e.g. acromegaly, hyperparathyroidism, hypothyroidism)
- metabolic disorders (e.g. gout, pseudogout, hemochromatosis, Wilson’s disease, ochronosis)
- neuropathic (e.g. Charcot joints)
- atypical joint trauma due to peripheral neuropathy (e.g. DM, syphilis)
- AVN
- other (e.g. congenital malformation)
Describe the pathophysiology of osteoarthritis?
- deterioration of articular cartilage due to local biomechanical factors, which leads to joint trauma and release of proteolytic and collagenolytic enzymes
- OA develops when cartilage catabolism > synthesis
- loss of proteoglycans and water exposes underlying bone
- abnormal local bone metabolism further damages joint
- altered joint function and damage
- synovitis is secondary to cartilage damage; therefore, may see small effusions in OA
Describe the epidemiology of osteoarthritis?
- most common arthropathy
- increased prevalence with increasing age (35% of 30 yr olds, 85% of 80 yr olds)
What are the risk factors for OA?
- genetic predisposition
- advanced age
- obesity (for knee OA)
- female
- trauma
What are the signs and symptoms of OA?
What are the common joints involved in OA?
What are the common hand findings of OA?
What Ix need to be done for OA?
- blood work
- normal FBC and ESR, CRP
- negative RF and ANA
- radiology: 4 hallmark findings
- synovial fluid: non-inflammatory
What are the 4 radiographic hallmark signs of OA?
- Joint space narrowing
- Subchondral sclerosis
- Subchondral cysts
- Osteophytes
What is the Rx for OA?
- presently no treatment alters the natural history of OA
- non-pharmacological therapy
- weight loss (minimum 5-10 lb loss) if overweight
- physiotherapy: heat/cold, low impact exercise programs
- occupational therapy: aids, splints, cane, walker, bracing
- pharmacological therapy
- oral: acetaminophen/NSAIDs, glucosamine ± chondroitin (nutraceuticals not proven)
- joint injections: corticosteroid, hyaluronic acid (questionable benefit)
topical: capsaicin, NSAIDs
- surgical treatment
- joint debridement, osteotomy, total and/or partial joint replacement, fusion
Define rheumatoid arthritis.
- chronic, symmetric, erosive synovitis of peripheral joints (e.g. wrists, MCPs, MTPs)
- characterized by a number of extra-articular features
Describe the pathophysiology of RA?
- autoimmune disorder, unknown etiology
- hallmark of RA is hypertrophy of the synovial membrane
- activated rheumatoid synovium (pannus) grows into and over the articular surface; inflammatory mediators lead to release of metalloproteinases and collagenases resulting in
destruction of articular cartilage and subchondral bone
- activated rheumatoid synovium (pannus) grows into and over the articular surface; inflammatory mediators lead to release of metalloproteinases and collagenases resulting in
- two theories attempt to explain chronic remissions and exacerbations seen in RA
- sequestered Ag
- during inflammation, immune complexes (ICs) are deposited at avascular cartilage-bone junction → immune complexes are released as further cartilage breaks down → triggers
inflammatory cascade
- during inflammation, immune complexes (ICs) are deposited at avascular cartilage-bone junction → immune complexes are released as further cartilage breaks down → triggers
- molecular mimicry
- cartilage damage → altered cartilage resembles undefined offending agent → triggers inflammatory cascade
- sequestered Ag
Describe the epidemiology of RA.
- prevalence 1% of adult population
- F:M = 3:1
- age of onset 20-40 yr
- genetic predisposition: HLA-DR4/DR1 association (93% of patients have either HLA type)
Describe the signs and symptoms of RA.
Joint specific.
- variable course of exacerbations and remissions
- morning stiffness >1 h, improves with use, increases with rest
- may have joint pain with activity
- symmetric joint involvement
- joint swelling, tender joints
- constitutional symptoms: profound fatigue; rarely myalgia or weight loss
- extra-articular features (EAF)
- limitation of function and decrease in global functional status
- complications of chronic synovitis
- signs of mechanical joint damage: loss of motion, instability, deformity, crepitus, joint deformities
- swan neck deformity, boutonnière deformity
- ulnar deviation of MCP, radial deviation of wrist joint
- hammer toe, mallet toe, claw toe
- flexion contractures
- atlanto-axial and subaxial subluxation
- C-spine instability
- neurological impingement (long tract signs)
- difficult/dangerous intubation: risk of worsening subluxation and damage to spinal cord
- limited shoulder mobility, spontaneous tears of the rotator cuff leading to chronic spasm
- tenosynovitis → may cause rupture of tendons
- carpal tunnel syndrome
- ruptured Baker’s cyst (outpouching of synovium behind the knee); presentation similar to acute DVT
- signs of mechanical joint damage: loss of motion, instability, deformity, crepitus, joint deformities
What are the extra-articular manifestations of RA?
What are the common sites of joint involvement in RA?
What are the types of joint deformaties seen in RA?
What are some syndromes associated with RA?
- Srögren’s Syndrome (common): keratoconjunctivitis, sicca and xerostomia (dry eyes and mouth)
- Caplan’s syndrome (rare): multiple pulmonary nodules and pneumoconiosis
- Felty’s syndrome (rare): arthritis, splenomegaly, neutropenia
What Ix need to be ordered for RA?
- blood work
- RF sensitivity ~80% but non-specific; may not be present at onset of symptoms
- anti-CCP: sensitivity ~80% but more specific; may precede onset of symptoms
- increased disease activity is associated with decreased Hb (anemia of chronic disease), increased platelets, ESR, CRP, and RF
- imaging
- x-rays may be entirely normal at onset
- first change is periarticular osteopenia, followed by erosions
- U/S, MRI may be used to image hands to detect early synovitis and erosions
What are the poor prognostic features of RA?
- young age of onset
- high RF titer
- elevated ESR
- activity of >20 joints
- presence of extra-articular features
What are the goals of therapy for RA?
- goals of therapy: remission or lowest possible disease activity
- control disease activity
- relieve pain and stiffness
- Maintain function and lifestyle
- prevent or control joint damage
- key is early diagnosis and early intervention with DMARDs
- “window of opportunity” = early treatment within first 3 mo of disease may allow better control/remission
What are the non-pharmacological Rx options for RA?
- Education
- Behavioural
- exercise program (isometrics and active, gentle ROM exercise during flares, aquatic/aerobic/strengthening exercise between flares), assistive devices as needed
- job modification may be necessary
What are the pharmacological Rx for RA?
- DMARDs and Biologics
- DMARDs: standard of care and should be started as soon as possible
- treatments guided by disease severity and prognostic features
- MTX is the gold standard and is first-line unless contraindicated
- delayed onset of action (may take 8-12 wk)
- potential toxicities: GI, hematologic, hepatic (liver enzymes), pulmonary, teratogenic
- if inadequate response (3-6 mo) → combine or switch
- add-ons include: hydroxychloroquine, sulfasalazine, leflunomide
- biologics: indicated if inadequate response to DMARDs
- can be combined with DMARD therapy
- agents include infliximab, etanercept, adalimumab, abatacept, rituximab, tocilizumab
- reassess every 3-6 mo and monitor disease severity
- Reducing Inflammation and Pain
- NSAIDs
- individualize according to efficacy and tolerability
- contraindicated or cautioned in some patients (e.g. PUD, ischemic cardiac disease, pregnancy); add acetaminophen ± opioid prn for synergistic pain control
- corticosteroids
- local
- IA injections to control symptoms in a specific joint
- systemic (prednisone)
- low dose (5-10 mg/d) useful for short-term to improve symptoms if NSAIDs ineffective, to bridge gap until DMARD takes effect
- for severe RA, low dose prednisone can be added to DMARDs
- do baseline DEXA bone density scan and consider bone supportive pharmacologic therapy if using corticosteroids >3 mo at >7.5 mg/d
- cautions/contraindications: active infection, TB, osteoporosis, HTN, gastric ulcer, DM
- local
- NSAIDs
What are the side effects of steroids?
- Weight gain
- Osteoporosis
- AVN
- Cataracts, glaucoma
- PUD
- Susceptibility to infection
- Easy bruising
- Acne
- HTN
- Hyperlipidemia
- Hypokalemia, hyperglycemia
- Mood swings
What are the surgical Rx options for RA?
- indicated for structural joint damage
- surgical options include: synovectomy, joint replacement, joint fusion, reconstruction/tendon repair
What is the diagnostic criteria for SLE?
MD SOAP BRAIN
- Malar rash
- Discoid rash
- Serositis
- Oral ulcers
- ANA
- Photosensitivity
- Blood
- Renal
- Arthritis
- Immune
- Neurologic
Define SLE.
- chronic inflammatory multi-system disease of unknown etiology
- characterized by production of autoantibodies and diverse clinical manifestations
What is the diagnostic criteria for SLE?
Describe the aetiology and pathophysiology of SLE.
- production of autoantibodies causing multi-organ inflammation
- multi-factorial aetiology
- genetics
- common association with HLA-B8/DR3; ~10% have positive FHx
- oestrogen
- pre-pubertal and post-menopausal women have similar incidence to men
- men with SLE have higher concentration of oestrogenic metabolites
- infection
- viral (non-specific stimulant of immune response)
- drug-induced
- anti-hypertensives (hydralazine), anti-convulsants (phenytoin), anti-arrhythmics (procainamide), isoniazid, biologics, OCPs
- anti-histone Ab are commonly seen in drug-induced SLE
- symptoms resolve with discontinuation of offending drug
DDx “flu-like symptoms”.
- Viral:
- Influenza
- HIV
- CMV
- Hepatitis A/B/C/D/E
- Chicken pox
- Bacterial:
- Pneumonia
- Syphilis
- TB
- Malignancy:
- Leukemias/lymphoma
- Hodgkins/non-Hodgkins lymphoma
- Drugs:
- Substance withdrawal
- IgA nephropathy
- Substance withdrawal
- Autoimmune
- Reiters syndrome
- Temporal arteritis
Describe the epidemiology of SLE.
- prevalence: 0.05% overall
- F:M = 10:1
- age of onset in reproductive yr (13-40)
- more common and severe in African Americans and Asians
- bimodal mortality pattern
- early (within 2 yr)
- active SLE, active nephritis, infection secondary to steroid use
- late (>10 yr)
- inactive SLE, inactive nephritis, atherosclerosis likely due to chronic inflammation
- early (within 2 yr)
What are the symptoms of SLE?
What Ix can be done in SLE?
- blood work: ANA (sensitivity 98%, but poor specificity → used as a screening test, ANA titres are not useful to follow disease course)
- anti-dsDNA and anti-Sm are specific (95-99%)
-
anti-dsDNA titer and serum complement (C3, C4) are useful to monitor treatment response in patients who are clinically and serologically concordant
- anti-dsDNA increases and C3 and C4 decrease with disease activity
- antiphospholipid Ab (anti-cardiolipin Ab and SLE anticoagulant), may cause increased risk of clotting and increased aPTT
Describe Raynaud’s Phenomenom?
- Vasospastic disorder characteristically causing discoloration of fingers and toes (white → blue → red)
- Classic triggers: cold and emotional stress
What are the Rx goals of SLE?
- treat early and avoid long-term steroid use, if unavoidable
- if high doses of steroids necessary for long-term control, add steroid-sparing agents and taper when possible
- treatment is tailored to organ system involved and severity of disease
- all medications used to treat SLE require periodic monitoring for potential toxicity
What are the Rx options for SLE?
Specifically dermatologic, MSK, and organ-threatening disease.
- dermatologic
- sunscreen, avoid UV light and estrogens
- topical steroids, hydroxychloroquine
- musculoskeletal
- NSAIDs ± gastroprotective agent for arthritis (also beneficial for pleuritis and pericarditis)
- hydroxychloroquine improves long-term control and prevents flares
- bisphosphonates, calcium, vitamin D to combat osteoporosis
- organ-threatening disease
- high-dose oral prednisone or IV methylprednisolone in severe disease
- steroid-sparing agents: azathioprine, MTX, mycophenolate
- IV cyclophosphamide for serious organ involvement (e.g. cerebritis or SLE nephritis)
What is CREST syndrome?
HINT: CREST
- Calcinosis: calcium deposits on skin
- Raynaud’s phenomenon
- Esophageal dysfunction: acid reflux
- Sclerodactyly: tightening of skin on digits
- Telangiectasia: superficial dilated blood vessels
Define gout.
- derangement in purine metabolism resulting in hyperuricemia; monosodium urate crystal deposits in tissues (tophi) and synovium (microtophi)
Describe the aetiology and pathogenesis of gout?
- sources of uric acid: diet and endogenous
- synthesis
- hypoxanthine → xanthine → uric acid both steps catalyzed by xanthine oxidase
What are the primary and secondary casues of hyperuricaemia?
- primary or genetic
- mostly due to idiopathic renal underexcretion (90%)
- also idiopathic overproduction or abnormal enzyme production/function
- secondary
- dietary excess (particularly high consumption of beer, seafood, and meat)
- underexcretion (>90%): renal failure, drugs, systemic conditions
- overproduction (<10%): increased nucleic acid turnover states (e.g. malignancy, post-chemotherapy)
- sudden changes (increasing or decreasing) in uric acid concentration are more important than absolute values
- acute gout can occur with normal serum uric acid
- changes in pH, temperature, or initiation of antihyperuricemics may precipitate an acute gouty attack
- common precipitants: alcohol, dietary excess, dehydration, drugs (e.g. thiazide and loop diuretics), trauma, illness, surgery, starting xanthine oxidase inhibitor therapy
- other associated conditions: HTN, obesity, DM, starvation
What are the signs and symptoms of gout?
- single episode progressing to recurrent episodes of acute inflammatory arthritis
- acute gouty arthritis
- severe pain, redness, joint swelling, usually involving lower extremities
- joint mobility may be limited
- attack will subside spontaneously within several days to weeks; may recur
- tophi
- urate deposits on cartilage, tendons, bursae, soft tissues, and synovial membranes
- common sites: first MTP, ear helix, olecranon bursae, tendon insertions (common in Achilles tendon)
- kidney
- gouty nephropathy
- uric acid calculi
What Ix need to be done for gout?
- joint aspirate: >90% of joint aspirates show crystals of monosodium urate
(negatively birefringent, needle-shaped) - x-rays may show tophi as soft tissue swelling, punched-out lesions – erosion with “overhanging” edge
What is the Rx for gout?
Acute
- NSAIDs: high dose, then taper as symptoms improve
- corticosteroids: IA, oral, or intra-muscular (if renal, cardiovascular, or GI disease and/or if NSAIDs contraindicated or failed)
- colchicine within first 12 h but effectiveness limited by narrow therapeutic range
- allopurinol can worsen an acute attack (do not start during acute flare)
What is the Rx for gout?
Chronic
- conservative
- avoid foods with high purine content (e.g. visceral meats, sardines, shellfish, beans, peas)
- avoid drugs with hyperuricemic effects (e.g. pyrazinamide, ethambutol, thiazide, alcohol)
- medical
- antihyperuricemic drugs (allopurinol and febuxostat): decrease uric acid production by inhibiting xanthine oxidase
- uricosuric drugs (probenecid, sulfinpyrazone): use if failure on or intolerant to allopurinol; do not use in renal failure
- prophylaxis prior to starting antihyperuricemic drugs (colchicine/low-dose NSAID)
- in renal disease secondary to hyperuricemia, use low-dose allopurinol and monitor Cr
- indications for treatment with antihyperuricemic medications include:
- recurrent attacks, tophi, bone erosions, urate kidney stones
- perhaps in renal dysfunction with very high urate load (controversial)
What are the common sites of involvement in gout?
What are the side effects of allopurinol?
- Skin rash - maculopapular
- Allopurinol hypersenitivity syndrome: fatal, erythematous desquamating rash, fever, hepatitis, eosinophilia, and worsening renal function.
Define antiphospholipid antibody syndrome, and the causes?
- multi-system vasculopathy manifested by recurrent thromboembolic events, spontaneous abortions, and thrombocytopenia
- often presents with migraine-type headaches
- circulating antiphospholipid autoantibodies interfere with coagulation cascade
- primary APLA: occurs in the absence of other disease
- secondary APLA: occurs in the setting of a connective tissue disease (including SLE), malignancy, drugs (hydralazine, procainamide, phenytoin, interferon, quinidine), and infections (HIV, TB, hepatitis C, infectious mononucleosis)
- catastrophic APLA: development within 1 wk of small vessel thrombotic occlusion in ≥3 organ systems with positive antiphospholipid Ab (high mortality)
How does antiphospholipid antibody syndrome manifest?
- Thromboembolic events: Artherial and venous thrombosis are usually mutually exclusive.
- Renal vein thrombosis
- Glomerular thrombosis
- MI
- TIAs
- Spontaneous abortions
- Thrombocytopenia, haemolytic anaemia, neutropenia
- Dermatologic
- livedo reticularis
- Raynaud’s phenomenon
- pupura
- leg ulcers
- gangrene
- Migrane headaches
- Addison’s disease
- Epilepsy
What is the Rx for antiphospholipid antibody syndrome?
- thrombosis
- lifelong anti-coagulation with warfarin
- target INR 2.0-3.0 for first venous event, >3.0 for recurrent and/or arterial event
- recurrent fetal loss
- heparin/low molecular weight heparin ± Aspirin® during pregnancy
- catastrophic APLA
- high-dose steroids, anti-coagulation, cyclophosphamide, plasmapheresis
Define adult onset stills disease?
- systemic inflammatory condition (ANA and RF negative) with fevers and characteristic rash, numerous systemic symptoms, and may have severe arthritis
What is the aetiology of Adult onset Stills disease?
- idiopathic; infectious triggers likely – various viruses and bacteria have been implicated
- stress increases risk
What is the classic triad for Stil’s disease?
HINT: FAR
- Fever
- Arthralgias/Arthritis
- Rash
What are the signs and symptoms of Adult onset Stills disease?
- classic triad of symptoms
- high-spiking fevers (95.7% of patients, typically T = 102.2ºF/39°C, <4 h duration, quotidian pattern)
- characteristic “salmon rash” (~72% of patients, on proximal limbs + trunk)
- arthralgia/arthritis (64-100%)
- sore throat, myalgias and serositis may also occur
- arthritis is symmetric, typically affects large joints, i.e. wrists, knees and ankles, may involve PIP and DIPs, elbow, MTPs
- liver abnormalities ± hepatomegaly (50-75% patients)
- splenomegaly (44%)
What Ix need to be done with suspected adult onset Stills disease?
- ANA and RF negative
- markedly elevated ESR, CRP, ferritin (typically >1000 ng/mL, >2200 pmol/L) total ferritin >5x ULN = 80% sensitive, 41% specific
- anemia, thrombocytosis, leukocytosis may occur
- transaminases, LDH may be elevated
What is the Rx for adult onset stills?
- refer to rheumatologist for treatment with biologics (anti-IL1 and anti-IL6 agents)
- begin management with low-dose glucocorticoids ± MTX
What are the radiological features of rheumatoid arthritis?
- Joint space narrowing
- periarticular osteoporosis
- Erosions
- Periarticular soft tissue swellinig
- Later joint destruction or subluxation
Behçet’s syndrome is characterised by?
- Recurrent oral and genital ulcers
- Uveitis
- Seronegative arthritis
- Central nervous system symptoms
- Fever
- Thrombophlebitis
- Erythema nodosum
- Abdominal symptoms, and
- Vasculitis.