Systemic Lupus Erythematosus Flashcards
Describe the spectrum of severity in lupus
- mild
- moderate
- severe
Mild => MSK, mucocutaneous
Moderate => serositis, cardiopulmonary, vasculitis
Severe => nephritis, CNS lupus, thrombosis
What investigation results are typical of lupus
High ESR
CRP = 0
Cytopenia
Low complement
ANA, dsDNA
Anemia, leukocytopenia, thrombocytopenia => direct cytotoxicity
What is the difference between ESR and CRP
ESR => increased fibrinogen
CRP => acute inflammation
What autoantibodies can you find in SLE
-what symptoms arise as a result
ANA (more sensitive marker, but not specific) A dsDNA (more specific to lupus)
ENAs
- Ro => photosensitivity
- La => neonatal lupus
- RNP => Raynaud’s
- Sm => SLE specific
Describe the pathophysiology of SLE
Environmental triggers
- sunlight
- drugs/chemicals/smoking
- viruses
Genetic predisposing factors
- increased apoptosis+ decreased clearance of apoptotic bodies => necrosis, release nuclear antigens
- neutrophil extracellular traps exposes histone complex AG
Leads to clinical disease
- follicular DC, autoreactive B cells => IFNa release
- autoantibody producing plasma cells => complement fixing to immune complexes => organ involvement/damage
Eventually leads to comorbidities
Describe the epidemiology of SLE
Describe the genetic impact
More common in females (due to double genetic load of X)
-common onset after menarche, declines with menopause
African, Asian ancestry
-decreased inhibitory function of FCGR2B gene => protection against severe malaria but increased B cell activation
Genetics => monozygotic significantly increased risk (HLA region C6)
How may a patient with lupus present non specifically
Fatigue Photosensitive rash Inflammatory arthritis/aches, pains Mouth ulcers Hair loss
Describe the different presentations of lupus
-3 possible skin presentations
Discoid
- well demarcated scaly, atrophic, discoid plaques
- face, neck and trunk
Subacute subcutaneous
-well demarcated red, scaly patches on photosensitive regions
Chronic cutaneous
- chilblains on hands and feet
- cold to the touch
Describe the different presentations of lupus
-joints
Jaccoud’s arthritis
- deformation due to tendon inflammation
- swan neck, hitchickers thumb
- have full function of hands (different to RA)
Describe the different presentations of lupus
-vascular
Cutaneous vasculitis
- splinter haemorrhages
- digital infarcts
- palpable purpura
- vasculitic ulcers (inflammation affecting integrity of small vessels)
- urticarial vasculitis (T3 hypersensitivity)
Lupus vasculitis (medium/large vessels) -digital ischemia/gangrene
What are the comorbidities that accompany lupus
CVD
Cancer
Infection
Renal
Describe the pathophysiology behind the 5 cardiovascular comorbidities
Lupus atherosclerosis => accelerated due to inflammatory activity => multivessel disease
Peripheral vascular disease
-digital/limb ischemia => gangrene => amputation
Pericarditis
- rapid resolution with CS
- may lead to tamponade
Myocarditis => scars
- arrythmias/conduction abnormalities
- dilated cardiomyopathy
- HF
Endocarditis
Describe the pathophysiology behind the infective comorbidities
-pulmonary
Lupus pneumonitis, serositis (pleural effusion due to PM inflammation)
What are the presentations of neuropsychiatric lupus
Psychosis/psychological disorders
Strokes/seizures
Transverse myelitis
Describe the investigations that indicate an increased risk of lupus nephritis
How would lupus nephritis present
High anti dsAB
Low C3-4
Damage and scarring found on renal biopsy
Asymptomatic proteinuria
Nephrotic syndrome
Renal failure
Rapid glomerulonephritis
