Systemic lupus erythematosus, SLE or lupus, is an autoimmune disease of unknown aetiology. Lupus is a long term health condition with no known cure. It is the most commonly presenting connective tissue disease (CTD) and can present in a variety of forms, some of which may be life threatening. It is ten times more common in women than men and is classified as follows:-

• SLE - a diffuse multi-system disease affecting the skin, joints and internal organs
• Discoid lupus erythematosus (DLE) - primarily affecting the skin
• Drug associated lupus-like syndrome - also referred to as Drug-induced lupus.

In lupus the immune system produces too many antibodies (specific blood proteins) due to deficiencies in cellular waste product removal. Instead of defending the body from infection, these antibodies attack the patient’s own healthy tissue and organs. This can directly or indirectly cause problems in almost any part of the body by inflaming and occasionally damaging the tissue. The antibodies are often directed against components of the cell (self-antibodies) including some that target the components of the nucleus such as doublestranded (ds) deoxyribonucleic acid (DNA)( i.e. the test is referred to as antidsDNA). When triggered, these proteins form complexes which can cause inflammation in the skin (causing rashes), the walls of blood vessels along with other organs including the kidney, brain, lungs, heart, and joints. In most cases and when treated early enough, after the inflammation settles down the tissues or affected organs recover leaving no permanent damage. A principle aim of treatment is to detect this inflammation early, preventing permanent tissue damage.

The name lupus is derived from the Latin for ‘wolf’ describing the pattern of the red facial rash that was thought to resemble a wolf’s mask or a wolf bite. Lupus commonly affects women in their child bearing years, although men, children and new-born babies can develop the disease, with a ratio of 9 women to 1 man diagnosed. It is thought that currently up to 50,000 people in the UK have lupus,
about 1 in 1000 people. Although it is difficult to estimate the incidence (the new diagnosis each year) in such a disease, figures suggest 4.9 cases per 100,000 people per year in the UK in 2012. Lupus is most commonly seen in those of Afro-Caribbean, Asian and Hispanic heritage. Lupus is known as the greatest mimic and can be difficult to diagnose. Signs and symptoms can be non-specific, resembling other conditions such as rheumatoid arthritis and multiple sclerosis. Lupus is now thought to be more common worldwide than leukaemia, multiple sclerosis, and many other well-known diseases.

There is no one single cause that leads to someone developing lupus, although research has indicated a number of factors, including genetics, hormones and certain infections including viruses. There is about a 3-10% chance of family members developing lupus or other associated connective tissue diseases such as mixed connective tissue disease (MCTD) or Sjögren’s syndrome. Women commonly present during puberty, and during reproductive years and less often after the menopause. It is important to note that in most cases lupus is manageable by medication and patients can live normal and rewarding lives.