Systemic lupus erythematosus

Question 1

How would you define SLE?

Answer 1

SLE is an inflammatory, multisystem autoimmune disorder with arthralgia and rashes as the most common clinical features, and cerebral and renal disease as the most serious problems.

Question 2

What is the age of onset for SLE?

Answer 2

20-40

Question 3

What is the gender bias in SLE?

Answer 3

9:1 female:male

Question 4

What ethnic group has the highest incidence of SLE?

Answer 4

African/Caribbean women

Question 5

What factors expose someone to develop SLE?

Answer 5

1. Heredity
2. Genetics
3. Sex hormone status (mainly premenopausal women)
4. Drugs
5. Ultraviolet light
6. Exposure to Epstein-Barr virus

Question 6

What is the prognosis for SLE?

Answer 6

An episodic course is characteristic, with exacerbations and complete remissions that may last for long periods.

However, SLE can also be a chronic persistent condition.

The mortality rate in SLE has fallen dramatically over the last 50 years; the 10-year survival rate is about 90%, but this is lower if major organ-based complications are present.

Question 7

What are early deaths in SLE often due to?

Answer 7

renal or cerebral disease or infection

Question 8

What is the cancer risk associated with SLE?

Answer 8

Increased chance of lymphoma

Question 9

How would you manage an SLE patient?

Answer 9

Patients are advised to avoid excessive exposure to sunlight and it is also necessary to reduce cardiovascular risk factors

Many patients do not need treatment with corticosteroid tablets or immunosuppressive agents. Arthralgia, arthritis, fever and serositis all respond well to standard doses of NSAIDs

Single intramuscular injections of long-acting corticosteroids or short courses of oral corticosteroids are useful in treating severe flares of arthritis, pleuritis or pericarditis.

Renal or cerebral disease and severe haemolytic anaemia or thrombocytopenia must be treated with high-dose oral corticosteroids and the first two of these require immunosuppressive drugs in addition

Question 10

How is SLE diagnosed?

Answer 10

Signs and symptoms of lupus may change over time and overlap with those of many other disorders.

No one test can diagnose lupus. The combination of blood and urine tests, signs and symptoms, and physical examination findings leads to the diagnosis.

1. Complete blood count
2. Erythrocyte sedimentation rate → faster than normal indicates systemic disease
3. Kidney and liver assessment → involvement of organs
4. Urinalysis → assess kidney involvement
5. Antinuclear antibody (ANA) test
   
   • While most people with lupus have a positive ANA test, most people with a positive ANA do not have lupus

Question 11

What are the most common and general features in SLE?

Answer 11

The manifestations of SLE vary greatly between patients. Most patients suffer fatigue, arthralgia and/or skin problems. Involvement of major organs is less common but more serious

Fever is common in exacerbations. Patients complain of marked malaise and tiredness and these symptoms do not correlate with disease activity or severity of organ-based complications.

Question 12

How are the joints and muscles involved in SLE?

Answer 12

Joint involvement is the most common clinical feature (>90%)

• Patients often present with symptoms resembling RA with symmetrical small joint arthralgia
• Joints are painful but characteristically appear clinically normal
• Myalgia is present in up to 50% of patients but a true myositis is seen only in <5%

Question 13

How is the skin involved in SLE?

Answer 13

• Skin is affected in 85% of cases
• Erythema, in a ‘butterfly’ distribution on the cheeks of the face and across the bridge of the nose is characteristic
• Vasculitic lesions on the finger tips and around the nail folds, purpura and urticaria occur
• In 40–50% of cases there is photosensitivity

Question 14

How are the lungs involved in SLE?

Answer 14

Up to 50% of patients will have lung involvement sometime during the course of the disease.

Recurrent pleurisy and pleural effusions (exudates) are the most common manifestations and are often bilateral and atelectasis are seen; eventually a restrictive lung defect develops with loss of lung volumes and raised hemidiaphragms

Question 15

How are the kidneys involved in SLE?

Answer 15

Autopsy studies suggest that histological changes are very frequent, but clinical renal involvement occurs in only approximately 30% of cases.

• All patients should have regular screening of urine for blood and protein
• An asymptomatic patient with proteinuria may be in the early stages of lupus nephritis, and treatment may prevent progression to renal impairment
• Proteinuria should be quantified and haematuria should prompt examination for urinary casts or fragmented red cells that suggest glomerulonephritis

Question 16

How are is the nervous system involved in SLE?

Answer 16

Involvement of the nervous system occurs in up to 60% of cases and symptoms often fluctuate. There may be a mild depression but occasionally more severe psychiatric disturbances occur

• Epilepsy, migraines, cerebellar ataxia, aseptic meningitis, cranial nerve lesions, cerebrovascular disease or a polyneuropathy may be seen

Question 17

How are the eyes involved in SLE?

Answer 17

Retinal vasculitis can cause infarcts (cytoid bodies) which appear as hard exudates, and haemorrhages. There may be episcleritis, conjunctivitis or optic neuritis, but blindness is uncommon. Secondary Sjögren’s syndrome is seen in about 15% of cases

Question 18

How are is the GI system involved in SLE?

Answer 18

Mouth ulcers are common and may be a presenting feature.

Question 19

What is the pathophysiological basis of the development of SLE?

Answer 19

When cells die by apoptosis, the cellular remnants appear on the cell surface as small blebs which carry self-antigens

In people with SLE, removal of these blebs by phagocytes is inefficient so that they are transferred to lymphoid tissues where they can be taken up by antigen- presenting cells.

In people with SLE, removal of these blebs by phagocytes is inefficient so that they are transferred to lymphoid tissues where they can be taken up by antigen- presenting cells.

This leads to:

1. Development of autoantibodies that either form circulating complexes or deposit by binding directly to tissues
2. This leads to activation of complement and influx of neutrophils causing inflammation in those tissues
3. Abnormal cytokine production: increased blood levels of IL-10 and alpha-interferon are particularly closely linked to high activity of inflammation in SLE.

Question 20

What antibodies are often present in patients with SLE?

Answer 20

Antinuclear antibody (ANA)

anti DS DNA