Systemic Lupus Erythematosus Flashcards
What diseases come under the category of ‘connective tissue disease’?
SLE Systemic sclerosis Dermatomyositis/polymyositis Sjogren’s syndrome Mixed connective tissue disease
Which gender does SLE more commonly affect?
Females 9:1
Describe the presentation of SLE including some specific features.
Malaise, fatigue, weight loss, fever, lymphadenopathy Specific features: Butterfly rash Alopecia Arthralgia Long history of Raynaud’s phenomenon
Describe the characteristics of the rash seen in SLE.
It tends to go across the nose It may look a bit like acne It is not painful or itchy Some rashes become depigmented when the inflammation spreads to the dermis (depigmentation and scarring is irreversible)
Describe the pathogenesis of SLE.
SLE patients have a defect in apoptosis Apoptotic cells are not cleared properly so they persist and expose their nuclear antigens and autoantibodies are generated against these nuclear antigens The defect in apoptosis is combined with B cell hyperactivity The overactive B cells are exposed to the nuclear antigens and the plasma cells begin to produce autoantibodies that circulate and form immune complexes The immune complexes deposit in tissues and activate complement leading to inflammation
What is the first investigation performed in the diagnosis of SLE?
Check for anti-nuclear antibodies (this is not specific for SLE though)
The pattern with which the antinuclear antibodies bind to the nuclear antigens is important in reaching a diagnosis. List some different patterns and the antigens they are associated with.
Homogenous – DNA Speckled – antibodies to Ro, La, Sm and RNP Nucleolar – topoisomerase – scleroderma Centromere – limited cutaneous scleroderma
What conditions are associated with the presence of anti-Ro and anti-La antibodies?
Neonatal lupus syndrome Subacute cutaneous lupus erythematosus
What are some other tests that can be done for SLE?
Measuring complement levels Anti-cardiolipin antibodies Lupus anticoagulant Beta 1 glycoprotein
Describe the haematological features of SLE.
SLE is generally associated with low blood counts Thrombocytopenia Lymphopenia Normocytic anaemia Autoimmune haemolytic anaemia
What renal changes might occur in SLE?
Proteinuria Haematuria Active urinary sediment
List some clinical features that could help pre-empt severe attacks in SLE.
Malaise, weight loss, alopecia, rash
List some laboratory markers that could help pre-empt severe attacks in SLE.
Raised ESR Raised anti-dsDNA antibodies Reduced complement levels
Describe the differences between mild, moderate and severe disease in SLE.
Mild – skin and joint involvement Moderate – inflammation of other organs (e.g. pleuritis, pericarditis) Severe – severe inflammation of vital organs
Describe the treatment of mild disease.
Paracetamol and NSAIDs Hydroxychloroquine (good for arthropathy and cutaneous manifestations) Topical corticosteroids
Describe the treatment of moderate disease.
ORAL GLUCORTICOIDS Start with a HIGH dose and titre downwards
Describe the treatment of severe disease.
Azathioprine – useful steroid-sparing drug Has a risk of neutropenia/bone marrow suppression so needs regular blood monitoring Cyclophosphamide – one used if there is severe organ involvement Problem – infertility
Name and explain the mechanism of action of two new treatments for severe disease.
Mycophenolate mofetil Reversible inhibitor of inosine monophosphate dehydrogenase This is the rate limiting step in de novo purine synthesis Lymphocytes rely heavily on de novopurine synthesisRituximab Anti-CD20 antibody Causes depletion of B cells Useful in lupus nephritis
SLE has and early peak and a late peak in mortality. What are the usual causes of the two peaks?
Early – renal failure, CNS disease, infection Late – MI and stroke
What can usually be seen on the blood film of a patient with SLE?
Schistocytes (evidence of microangiopathic haemolytic anaemia) Teardrop cells Spherocytes Few leukocytes Few platelets
Describe the appearance of a renal biopsy in a patient with SLE
Hypercellular Mesangial proliferation Crescent development
AssessingDisease Severity
•Identify the pattern oforganinvolvement•Monitor function of affected organs(renal, lung, CVS, skin)•Identify pattern ofautoantibodiesexpresse
