Systemic lupus erythematosus Flashcards
What is the gender ratio for systemic lupus erythematosus (SLE)?
SLE is much more common in females, with a ratio of 9:1 (F:M).
In which communities is systemic lupus erythematosus more common?
SLE is more common in Afro-Caribbeans and Asian communities.
What is the typical age of onset for systemic lupus erythematosus?
The onset of SLE is usually between 20 to 40 years.
How has the incidence of systemic lupus erythematosus changed over the past 50 years?
The incidence of SLE has risen substantially, increasing threefold using American College of Rheumatology criteria.
What type of hypersensitivity reaction is systemic lupus erythematosus?
SLE is classified as an autoimmune disease and a type 3 hypersensitivity reaction.
What genetic associations are linked to systemic lupus erythematosus?
SLE is associated with HLA B8, DR2, and DR3.
What causes systemic lupus erythematosus?
SLE is thought to be caused by immune system dysregulation leading to immune complex formation.
What organs can be affected by immune complex deposition in systemic lupus erythematosus?
Immune complex deposition in SLE can affect any organ, including the skin, joints, kidneys, and brain.
How does the incidence of systemic lupus erythematosus in black Africans compare to black Americans?
The incidence of SLE in black Africans is said to be much lower than in black Americans, though the reasons for this are unclear.
What is systemic lupus erythematosus (SLE)?
A multisystem, autoimmune disorder that typically presents in early adulthood and is more common in women and people of Afro-Caribbean origin.
What are general features of SLE?
Fatigue, fever, mouth ulcers, lymphadenopathy.
What skin features are associated with SLE?
Malar (butterfly) rash, discoid rash, photosensitivity, Raynaud’s phenomenon, livedo reticularis, non-scarring alopecia.
Describe the malar (butterfly) rash in SLE.
It spares the nasolabial folds.
Describe the discoid rash in SLE.
A scaly, erythematous, well demarcated rash in sun-exposed areas that may progress to become pigmented and hyperkeratotic before becoming atrophic.
What musculoskeletal features are associated with SLE?
Arthralgia and non-erosive arthritis.
What cardiovascular features are associated with SLE?
Pericarditis (the most common cardiac manifestation) and myocarditis.
What respiratory features are associated with SLE?
Pleurisy and fibrosing alveolitis.
What renal features are associated with SLE?
Proteinuria and glomerulonephritis (diffuse proliferative glomerulonephritis is the most common type).
What neuropsychiatric features are associated with SLE?
Anxiety and depression, psychosis, seizures.
What percentage of patients with systemic lupus erythematosus are ANA positive?
99% are ANA positive
This high sensitivity makes it a useful rule out test, but it has low specificity.
What percentage of patients with systemic lupus erythematosus are rheumatoid factor positive?
20% are rheumatoid factor positive.
What is the specificity and sensitivity of anti-dsDNA antibodies?
Anti-dsDNA: highly specific (> 99%), but less sensitive (70%).
What is the specificity and sensitivity of anti-Smith antibodies?
Anti-Smith: highly specific (> 99%), sensitivity (30%).
What other antibodies are associated with systemic lupus erythematosus?
Also: anti-U1 RNP, SS-A (anti-Ro) and SS-B (anti-La).
What inflammatory marker is generally used for monitoring systemic lupus erythematosus?
ESR is generally used.
What does a raised CRP indicate during active disease?
A raised CRP may indicate underlying infection.
What happens to complement levels (C3, C4) during active disease?
Complement levels (C3, C4) are low during active disease.
What can anti-dsDNA titres be used for?
Anti-dsDNA titres can be used for disease monitoring
Note that anti-dsDNA is not present in all patients.
What is the treatment of choice for systemic lupus erythematosus (SLE)?
Hydroxychloroquine
What should be considered if there is internal organ involvement in SLE?
Consider prednisolone or cyclophosphamide
Examples of internal organ involvement include renal, neuro, and eye issues.
What are two basic management strategies for SLE?
NSAIDs and sun-block
What is lupus nephritis?
Lupus nephritis is a severe manifestation of systemic lupus erythematosus (SLE) that can result in end-stage renal disease.
How should SLE patients be monitored for renal complications?
SLE patients should be monitored by performing urinalysis at regular check-up appointments to rule out proteinuria.
What are the WHO classifications of lupus nephritis?
- Class I: normal kidney
- Class II: mesangial glomerulonephritis
- Class III: focal (and segmental) proliferative glomerulonephritis
- Class IV: diffuse proliferative glomerulonephritis
- Class V: diffuse membranous glomerulonephritis
- Class VI: sclerosing glomerulonephritis
Which class of lupus nephritis is the most common and severe?
Class IV (diffuse proliferative glomerulonephritis) is the most common and severe form.
What are the characteristic findings of renal biopsy in Class IV lupus nephritis?
- Glomeruli show endothelial and mesangial proliferation, ‘wire-loop’ appearance.
- If severe, the capillary wall may be thickened secondary to immune complex deposition.
- Electron microscopy shows subendothelial immune complex deposits.
- Granular appearance on immunofluorescence.
What is the management for lupus nephritis?
- Treat hypertension.
- Initial therapy for focal (class III) or diffuse (class IV) lupus nephritis includes glucocorticoids with either mycophenolate or cyclophosphamide.
- Mycophenolate is generally preferred to azathioprine to decrease the risk of developing end-stage renal disease.
