title: Pseudohyponatraemia in a patient with obstructive jaundice.
abstract: BACKGROUND
  Pseudohyponatraemia is uncommonly associated with severe hypercholesterolaemia. Severe hypercholesterolaemia encountered in obstructive jaundice due to an abnormal lipoprotein, lipoprotein X (LpX), may result in pseudohyponatraemia.
  
  
  METHODS
  We report a case of falsely low sodium measurements in a patient with severe hypercholesterolaemia due to obstructive liver disease. The pathophysiology, complications and analytical effects of LpX are briefly discussed.
  
  
  CONCLUSIONS
  The possibility of pseudohyponatraemia should be considered in severely hypercholesterolaemic samples.
authors.affiliation: Department of Chemical Pathology, National Health Laboratory Service (NHLS), Tygerberg Hospital, University of Stellenbosch, P.O. Box 19113, Tygerberg 7505, Parow, South Africa. mleriche@sun.ac.za
authors.forename: Mia
authors.initials: M
authors.lastname: le Riche
authors.forename: Lesley J
authors.initials: LJ
authors.lastname: Burgess
authors.forename: A David
authors.initials: AD
authors.lastname: Marais
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D004587:Electrophoresis, Agar Gel; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000175:diagnosis / Q000209:etiology; D007010:Hyponatremia / Q000175:diagnosis* / Q000209:etiology; D041781:Jaundice, Obstructive / Q000150:complications* / Q000378:metabolism; D008073:Lipoprotein-X / Q000032:analysis
chemical_list: D008073:Lipoprotein-X