Connective tissue disorders Flashcards
What is SLE?
AKA Lupus. Multi-system inflammatory autoimmune disorder.
What is the aetiology of SLE? (x3)
- Unknown
- Genetic: HLA clustering and more common in those with complement deficiencies
- Hormonal: female preponderance
- Exogenous factors: drugs such as hydralazine and procainamide that can cause a reversible SLE-like disorder
What is the pathophysiology of SLE?
SLE is characterised by autoimmune IgG antibodies to ds-DNA and nuclear proteins. This leads to tissue damage as a result of vascular immune complex deposition.
What is the epidemiology of SLE: Age? Ethnicity? Gender?
More common in your (20-40 years), Afro-Caribbean and Chinese. Nine times more common in females.
!!! What are the signs and symptoms of SLE? (x10)
- SOAP BRAIN MD can be used to remember the symptoms highlighted
- GENERAL: fever, fatigue, weight loss, lymphadenopathy
- RAYNAUD’S PHENOMENON
- ORAL ULCERATION
- SKIN: malar rash, discoid lupus (red and scaly patches, often on face, which later heal with scarring and pigmentation), photosensitive rash, hair loss, vasculitis (digital infarcts), urticaria, purpura, bullae (fluid-filled sac), livedo reticularis (blotchy red/blue skin appearance from cutaneous thrombosis), Rowell’s syndrome (atypical erythema multiforme-like rash)
- MUSCULOSKELETAL: non-erosive arthritis, tendonitis, myopathy, avascular necrosis of femur head
- HAEMATOLOGICAL CYTOPENIAS: haemolytic anaemia, leukopenia, thrombocytopenia
- HEART: pericarditis, myocarditis, Libman-Sacks endocarditis (non-infective mitral valve disease), aortic valve lesions
- LUNG: pleuritis, pleural effusions, basal atelectasis, restrictive picture
- NEUROLOGICAL: headache, stroke, CN palsies, peripheral neuropathy, seizures
- RENAL: glomerulonephritis
Note about SLE and serous tissue?
SLE causes serositis – inflammation of serous tissues of the body (lining of body cavities that secretes serum for lubrication). For example, pleuritis, pericarditis.
What are the investigations for SLE? (x4 +3)
- BLOOD: cytopenias, U&Es (renal manifestations), high CRP (and ESR),
- AUTOANTIBODIES: next flashcard
- URINE: haematuria, proteinuria, and microscopy for CASTS
- X-RAYS: CXR for effusions, infiltrates and cardiomegaly, joint x-rays show inflammation but no erosion
- There are loads: Renal biopsy if glomerulonephritis suspected, MRI scan/LP for CNS manifestations, ECG for heart manifestations
What are the autoantibodies in SLE? (x7 +2)
- ANA: 100% of cases
- Anti-dsDNA: 60% of cases
- RF: 30-50% of cases
- Anti-RNP: 30% of cases
- Anti-Sm: 30% of cases
- Anti-Ro: an ANA in 30% of cases and found in Sjogren’s syndrome
- Anti-La: an ANA in 15% of cases and found in Sjogren’s syndrome
- Positive anti-phospholipid antibodies
- Positive Coomb’s test
How is SLE diagnosed?
Positive ANA when it occurs together with the ACR 1997 revised criteria for the classification of SLE.
What is Sjogren’s syndrome?
Characterised by inflammation and destruction of exocrine glands (usually salivary and lacrimal glands.
What is the aetiology of Sjogren’s syndrome? (x2)
- PRIMARY: unknown but associated with HLA-B8, HLA-A1, and HLA-DR3
- SECONDARY: RA, scleroderma, SLE, organ-specific autoimmune diseases such as hepatitis, thyroid disease and myasthenia gravis
What is the epidemiology of Sjogren’s syndrome: Age? Gender?
Bimodal age distribution: post-menarche in 20-30s and post-menopause in 50s. 9x more common in females.
What is the pathophysiology of Sjogren’s syndrome?
Hyper-reactive B cells infiltrate into salivary and lacrimal glands. Infiltration leads to cytokine secretion, production of autoantibodies, and secretion of metalloproteinases
What are the signs and symptoms of Sjogren’s syndrome? (x6 and x5 extra-exocrine)
- KERATOCONJUNCTIVITIS SICCA: dry eyes with secondary conjunctivitis
- XEROSTOMIA: dry mouth, with secondary dysphagia and increased incidence of oral fungal/bacterial infections
- Parotid/salivary gland enlargement
- DRY UPPER AIRWAYS: dry cough, recurrent sinusitis
- DRY VAGINA: may cause dyspareunia (painful sex)
- Reduced GU mucus secretion causing symptoms of reflux, gastritis and constipation
- NB: that dry mucous membranes is also a sign of systemic sclerosis, but not the chief symptom unlike in Sjogren’s syndrome
- GENERAL: fatigue, fever, depression
- VASCULITIS
- Arthralgias and myalgias
- Interstitial nephritis
- Lymphoma
What are the investigations for Sjogren’s syndrome? (x6)
- SCHIRMER’S TEST: filter paper strip places under eyelid and positive if less than 5 mm of the strip is wet in 5 mins.
- SIALOMETRY: measures salivary flow. Can also use PAROTID SIALOGRAPHY (x-ray after radio-opaque contrast medium into duct system; shows retention and abnormal duct anatomy from enlargement), and SALIVARY GLAND SCINTIGRAPHY (radioactive measure of salivary flow)
- AUTOANTIBODIES: next flashcard
- BLOOD: raised ESR, raised amylase if salivary glands involved
- LISSAMINE GREEN/FLUORSCEIN STAINS: show punctate or filamentary keratitis (clumps of mucus on the cornea), and corneal abrasion/ulceration, respectively. Both signs of keratoconjunctivitis sicca
- SALIVARY GLAND BIOPSY: mononuclear (B and T cell) infiltrates in perivascular and periductal areas
What are the auto-antibodies for Sjogren’s syndrome? (x5)
Anti-Ro (SS-A) and anti-La (SS-B). Not specific to Sjogren’s as found in other conditions such as SLE. ANA, anti-thyroglobulin and RF also present in many.
What is sclerodactyly?
Thickened, tight, shiny skin, causing hand to curl inward and loss of mobility. Arises from fibrosis.
What is microstomia?
Puckering and furrowing of perioral skin leading to small mouth.
! What are the main differentials between lcSS and dcSS?
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What additional symptoms may be seen in dermatomyositis? (x3)
Macular heliotrope rash of upper eyelids (small, flat blue-purple rash) with periorbital oedema – see photo. Gottren’s papules (scaly erythematous raised plaques on finger joints, periungual (around nail) telangiectasia, ragged cuticles), ‘mechanics’ hands (fissuring dermatitis of finger pads)
