title: [Phosphate disorders: hyperphosphatemia or pseudohyperphosphatemia?].
abstract: We report the case of a 79 year old woman presenting with progressive confusion and drowsiness. Renal insufficiency with hyperkalemia as well as hypercalcemia and severe hyperphosphatemia were diagnosed. Renal insufficiency improved with treatment. However, hyperphosphatemia persisted without apparent explanation. We discuss possible causes of hyper- and pseudohyperphosphatemia. Specifically, phosphate analysis may be disturbed by the paraproteins in patients with multiple myeloma, resulting in pseudohyperphosphatemia. We review the standard laboratory phosphate measurement and the mechanisms of interference with paraproteins.
authors.affiliation: Universitätsklinik für Allgemeine Innere Medizin, Inselspital Bern; Universitätsinstitut für klinische Chemie, Inselspital Bern.
authors.forename: Nicole
authors.initials: N
authors.lastname: Aeberhard
authors.affiliation: Universitätsklinik für Allgemeine Innere Medizin, Inselspital Bern; Universitätsinstitut für klinische Chemie, Inselspital Bern.
authors.forename: Christof
authors.initials: C
authors.lastname: Schild
authors.affiliation: Universitätsklinik für Allgemeine Innere Medizin, Inselspital Bern; Universitätsinstitut für klinische Chemie, Inselspital Bern.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rodondi
authors.affiliation: Universitätsklinik für Allgemeine Innere Medizin, Inselspital Bern; Universitätsinstitut für klinische Chemie, Inselspital Bern.
authors.forename: Christine
authors.initials: C
authors.lastname: Roten-Joss
authors.affiliation: Universitätsklinik für Allgemeine Innere Medizin, Inselspital Bern; Universitätsinstitut für klinische Chemie, Inselspital Bern.
authors.forename: Kristina
authors.initials: K
authors.lastname: Tänzler
mesh_terms: D000368:Aged; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D006942:Hypergammaglobulinemia / Q000097:blood / Q000175:diagnosis*; D054559:Hyperphosphatemia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D007147:Immunoglobulin Light Chains / Q000097:blood*; D007146:Immunoglobulin lambda-Chains / Q000097:blood*; D009101:Multiple Myeloma / Q000097:blood* / Q000175:diagnosis*; D010710:Phosphates / Q000097:blood*
chemical_list: D007147:Immunoglobulin Light Chains; D007146:Immunoglobulin lambda-Chains; D010710:Phosphates
keywords: Hyperphosphatämie; Multiples Myelom; Paraproteinämie; Pseudohyperphosphatämie; hyperphosphatemia; multiple myeloma; paraproteinemia; pseudohyperphosphatemia