ABSTRACT
Systemic lupus erythematosus (SLE) is a classical autoimmune connective tissue disease that affects all medical systems (Figure 10.1) and every race, but
Figure 10.1 Clinical features of SLE
with different clinical manifestations being more common in each. The common theme is the presence of circulating auto-antibodies and immune complexes that deposit in and
around blood vessel walls and induce complement mediated damage in various organs. Deficiency of the early components of the complement pathway is one cause of SLE, but these are extremely rare so in the majority the cause is unknown. Nevertheless, SLE has a multifactorial aetiology with a strong genetic influence in all races that is likely to result from inheritance of more than one gene. Environmental factors are also relevant with the high incidence in pre-menopausal females, the frequent onset during or after pregnancy indicating hormonal factors. Other environmental factors implicated in the aetiology include ultraviolet light, infection and administration of certain drugs.
