Systemic Lupus Erythematosus (SLE) – Causes and changes in the body

SLE is an inflammatory, multisystem disorder presents with pain in the joints and rashes as the most common symptoms, and cerebral and renal disease as the most serious problems.


To whom and where are SLE common?

SLE affects people world-wide but the incidence varies from country to country, with the commonest prevalence of 1:250 being in African American women. In other populations the frequency varies from 1:1000 and 1:10 000. It is about nine times commoner in women than in men, with a peak age of occurance between 20-40 years.

Causes of SLE

The cause of SLE is still unknown but there are quite a few predisposing factors:

Heredity, and genetic factors play roles in the occurrence of SLE. There is a higher occurrence rate in monozygotic twins (up to 25%) compared to dizygotic twins (3%). First-degree relatives have a 3% chance of acquiring the disease. Genetic factor is responsible for higher occurrence in Caucasians and Japanese.



Sex hormone status also play a role in the development of this disease. Premenopausal women are most commonly affected. SLE has also been found in males with Klinefelter's syndrome(XXY) a sex chromosome anomaly with disrupted hormonal status.

Environmental triggers for the development of SLE

Drugs such as hydralazine, methyldopa, isoniazid, D-penicillamine and minocycline can induce SLE. Flare up of the SLE can be induced by the contraceptive pill and hormone replacement therapy (HRT). Ultraviolet light is another well documented trigger. Viral cause has also been anticipated.



What happens in the body in SLE?

SLE is a disease in which there is extensive vasculitis affecting capillaries, arterioles and venules. Fibrinoid (an amorphous material) is found along blood vessels and fibers of the tissues. The synovial membrane of joints may be oedematous or in other words fluid filled and also contain fibrinoid deposits, which contain immune complexes. Haematoxyl in bodies (rounded blue homogeneous haematoxylin –stained deposits) are found in inflammatory infiltrates and are possibly is the result from the interaction of antinuclear antibodies and cell nuclei.