Laboratory tests and investigations

In this chapter an overview is provided of the investigations used in patients with systemic lupus erythematosus (SLE); these establish the abnormalities that can be found in each organ/system. Lupus is a very heterogeneous condition, affecting virtually every organ/system. In consequence, numerous investigations and tests are used to help make the diagnosis and define the extent of the organ/system involvement. The chapter is divided into investigations of the effects of SLE on the following systems: haematological, immunological, biochemical, renal, cardiovascular, pulmonary, gastroenterological, neurological, dermatological, and musculoskeletal. These targeted organ/system-based investigations can then be used to assess ongoing disease activity or the consequence of damage caused by previously active disease.