Systemic Lupus Erythematosus (SLE)

by Professor David Kandiah MBChB (Hons), MClinEd, MPH, MHL, MBA, PhD, FRACP

Systemic lupus erythematosus (also called SLE or lupus) is a chronic inflammatory disease that can affect the skin, joints, kidneys, lungs, nervous system, and/or other organs of the body. The most common early symptoms include skin rashes and arthritis, often accompanied by fatigue and fever. The clinical course of SLE varies from mild to severe, and typically involves alternating periods of remission and relapse. SLE occurs 9 times more often in women than in men. The disorder typically develops in people in their early twenties and thirties. SLE is more common in certain ethnic groups, particularly in blacks and Asians, who also tend to be more severely affected. SLE is an autoimmune disorder which develops when the body’s own immune system, which normally protects against invading infections and malignant change, begins to attack the patient’s own tissues with a “loss of self-tolerance”. This occurs first through the production of “auto-antibodies”. As the attack continues, other immune system cells join the fight. This leads to inflammation and deposition of immune complexes in organs which causes tissue damage. It is not known why this inflammatory reaction begins, but it probably occurs because of a combination of inborn or hereditary predispositions and environmental factors (such as viruses and ultraviolet rays). Recent research suggests that people affected by lupus may have a defect in the normal biological process of cellular death which then causes an abnormal stimulation of the immune system.

Once SLE is diagnosed or suspected, investigations should include:

  1. Full blood counts looking for any or a combination of the following: neutropenia, lymphopenia, thrombocytopenia, anaemia.
  2. Baseline renal and liver biochemistry. Urinalysis is useful for Haematuria and proteinuria with microscopy for urine red cell casts.
  3. Autoimmune serology including anti-nuclear antibodies which are positive in more than 95% of patients.
  4. Other autoantibodies need to be looked for e.g. antibodies to double-stranded DNA, extractible nuclear antigens (ENA) and antiphospholipid antibodies.
  5. Complement levels are useful as active immune complex deposition results in complement consumption.
  6. Chest X-rays can identify pleural effusions, cardiomegaly with a globular shape suggestive of pericardial effusions and interstitial lung changes.
  7. Further imaging may be performed as indicated e.g. with a high resolution CT chest, echocardiogram or CT pulmonary angiogram if symptoms suggestive of pulmonary embolus.

Management of SLE

While there is no cure for SLE, there are treatments available. Early diagnosis and appropriate treatment can help manage the symptoms of lupus and lessen the chance of permanent damage to organs or tissue. Once a lupus diagnosis is established, patients are assessed for damage to major organs (central nervous system, kidneys, heart, or lungs). Treatment depends on the activity and extent of the disease, and can range from over the counter pain relievers and anti-inflammatories to prescription medication, therapy, dietary changes, and lifestyle changes such as staying out of the sun, wearing sun block, and avoiding stress.

Specific medications that can help treat SLE and reduce organ damage:

  1. Nonsteroidal anti-inflammatory drugs are used to relieve achy joints and arthritis in mild lupus when pain is limited and organs are not affected.
  2. Antimalarial drugs, such as hydroxychloroquine, are often prescribed for arthritis, skin problems and have been shown to reduce risk of atherogenesis.
  3. Corticosteroids, such as prednisolone, are used for major organ involvement. The dosage prescribed will depend on the type of organ involvement,
    symptoms, and blood-test results.
  4. Immunosuppressive agents, such as azathioprine, methotrexate, cyclophosphamide, cyclosporine, and mycophenalate mofetil.

These very potent drugs help control the overactive but misdirected immune system in lupus patients. They help limit damage to major organs and are closely monitored to counter the potentially serious side effects and complications. Increasing research is being done to investigate the modulation of immune function in SLE with monoclonal antibody infusions like Rituximab. Immunomodulation of B-cells in SLE may well reduce many of the end-organ damage effects of the immune complex deposition.

Common Symptoms of SLE

  • Prolonged and extreme fatigue
  • Muscle and joint pain
  • Fever
  • Skin rashes
  • Kidney involvement (Nephritis)
  • Anaemia
  • Chest pain/ pleurisy
  • Butterfly rash on cheeks and nose
  • Sun or light sensitivity
  • Hair loss
  • Abnormal blood clotting
  • Eye disease
  • Mouth ulcers
  • Seizures