doi:10.1258/000456307781646049
© 2007 Association for Clinical Biochemistry
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Review Articles
David Sinclair and
Judith M Stevens
Department of Clinical Biochemistry, Wessex Renal and Transplant Service, Queen Alexandra Hospital, Portsmouth PO6 3LY, UK;
Department of Clinical Biochemistry, Wessex Renal and Transplant Service, Queen Alexandra Hospital, Portsmouth PO6 3LY, UK
Systemic vasculitis, although rare, is often diagnosed lateand long after the onset of symptoms. The small vessel vasculitidesare recognized clinically by their multisystem presentation,markers of inflammation and evidence for an acute glomerulonephritis(GN), with the most apparent organ involved directing referralto secondary care. Routine laboratory tests are usually non-specificin systemic vasculitis but the use of anti-neutrophil cytoplasmicantibodies (ANCAs) and glomerular basement membrane (GBM) antibodiescan aid diagnosis, treatment and monitoring decisions. Theseantibodies are detected and quantified by indirect immunofluorescence(IIF) and antigen-specific enzyme-linked immunosorbent assay(ELISA), usually in combination for ANCA, and ELISA systems(or direct IIF on kidney biopsy) for GBM antibodies. The presenceor absence of ANCA does not confirm or exclude the diagnosisof systemic vasculitis but negative and positive predictivevalues will be strongly influenced by clinical presentation.Various large studies have been unable to conclude that followingserial ANCA titres has great clinical utility in each case buteach patient must be considered on its own merits; for examplethe reappearance of ANCA in a patient who was rendered ANCAnegative following treatment is more likely to indicate relapse.The adoption of consensus guidelines that direct testing towardspatients with rapidly progressive GN, pulmonary haemorrhage,persistent and destructive ear, nose and upper airways problems,such as subglottic tracheal stenosis, a retro-orbital mass andcutaneous vasculitis with systemic features or peripheral neuropathy,will greatly increase the clinical utility and positive predictivevalue of these tests.
CiteULike Complore Connotea Del.icio.us Digg Reddit Technorati What’s this?
