Systemic Lupus Erythematosus Flashcards
What population is SLE most common in?
15-40yo women
SLE principally affects… (2) but can also affect… (3)
joints and skin
lungs, kidneys, haematology
Presentation of SLE? (5)
Malaise, fatigue, fever, weight loss, lymphadenopathy
Specific features of SLE? (4)
Butterfly rash, alopecia, arthralgia, Raynaud’s phenomenon
Other features of SLE? (5)
Inflammation of kidney, CNS, heart and lungs, accelerated atherosclerosis, vasculitis
Whats used to diagnose SLE?
ACR criteria, 4/11 confirms diagnosis
A fundamental part of the pathogenic process in SLE is….
a deficiency of the clearance of apoptotic cells, they generate more apoptotic cells e.g. in response to UV light, anti-nuclear antibodies generated
pathogenesis of SLE? (6 steps)
abnormal clearance of apoptotic cell material -> dendritic cell uptake of auto antigens and activation of B cells -> B cell Ig class switching and affinity mutation -> IgG autoantibodies -> immune Complexes -> complement activation, cytokine activation etc
Lab tests for SLE? (3)
Antinuclear antibodies
Anti-dsDNA and Sm (antibodies against double stranded DNA will be positive in SLE, and anti-Sm will be seen in 20% of patients)
Anti-Ro and/or La (Ro is more important- these antibodies can cross the placenta and cause heart block in a fetus):
What does homogenous staining of ANAbs suggest?
- Homogenous - Abs to DNA
What does speckled staining of ANAbs suggest?
- Speckled - Abs to Ro, La, Sm, RNP
What does nucleolar staining of ANAbs suggest?
- Nucleolar - topoisomerase – scleroderma
What does centromere staining of ANAbs suggest?
- Centromere - limited cutaneous scleroderma
What haematological signs suggests SLE? (6)
- Lymphopaenia, normochromic anaemia
- Leukopaenia, autoimmune haemolytic anaemia, thrombocytopaenia
What renal tests suggests SLE? (6)
- Proteinuria, haematuria
- Active urinary sediment
3 criteria for assessing SLE severity?
- Identify pattern of organ involvement
- Monitor function of affected organs
Renal - BP, U & E, urine sediment + Prot:Crea ratio
Lungs/CVS - lung function, echocardiography
Skin, haematology, eyes - Identify pattern of autoantibodies expressed
Anti-dsDNA, anti-Sm - renal disease
Anti-cardiolipin antibodies
SIGNS OF DISEASE ACTIVITY in SLE? (clinical features 6, lab markers 4)
- Weight loss, fatigue, malaise, hair loss
- Alopecia
- Rash
- ESR ESR will go up with active disease but CRP will stay flat (both are raised in rheumatoid arthritis)
- Increased complement consumption
- Increased anti-dsDNA
- Other Abs e.g. ANA (not a marker of disease activity) and CRP poor indicators
ESR in SLE?
Increased
CRP in SLE?
Flat
Complement levels in serum in SLE?
Diminished
Serum anti-dsDNAab in SLE?
Increased
Treatment of mild disease SLE? (3)
A. Paracetamol +/- NSAID
B. Hydroxychloroquine Can cause retinal problems
C. Topical corticosteroids
What is hydroxychloroquine used for and what side effect must you be aware of?
SLE and retinal problems
Treatment of moderate disease SLE?
Corticosteroids
- high initial dose to suppress disease activity (0.5-1.5mg/kg/day)
- i.v. methylprednisolone 3 x 0.5-1g per 24h
- initial oral dose for 4 weeks
- reduce slowly over 2-3 mths to 10 mg/d
- reduce slowly at 1mg per month
What indicates moderate SLE?
- failure of hydroxychloroquine/NSAID
- organ/life threatening disease
Treatment of severe disease SLE? (4)
Azathioprine
Cyclophosphamide
Mycophenolate mofetil
Rituximab and belimumab
Effect of Mycophenolate mofetil? Benefit of it?
- Reversible inhibitor of inosine monophosphate dehydrogenase
- Rate-limiting enzyme in de novo purine synthesis
- Lymphocytes – dependent upon de novo purine synthesis
- Won’t impair fertility
Effect of rituximib?
- Anti-CD20 depletes B cell
Early mortality causes of SLE? (3)
Renal failure, CNS disease, infection
Late mortality cause of SLE?
MI
What defines mild SLE?
joint +/- skin involvement
What defines moderate SLE? (3)
inflammation of other organs- pleuritis, pericarditis, mild nephritis
What defines severe SLE? (5)
severe inflammation in vital organs:
- severe nephritis
- CNS disease
- pulmonary disease
- cardiac involvement
- AIHA, Thrombocytopaenia, TTP