Multisystem diseases and the kidney.

disease that does not in some way affect the kidneys either directly as part of the disease process or as a result of treatment. In this review, ‘multisystem diseases’ are taken to mean those conditions characterised by systemic vasculitis unless otherwise specified. These rare diseases may present to almost any hospital physician, frequently with non-specific signs and symptoms, usually associated with an acute phase response (raised C-reactive protein (CRP) concentration, erythrocyte sedimentation rate (ESR) or plasma viscosity). Recognition of renal involvement by the detection of blood and protein on urine dipstick, even in the presence of a normal creatinine, provides both a clue to multisystem involvement and an early diagnostic opportunity with a renal biopsy.