Journal article
Pseudohypophosphatemia associated with high-dose liposomal amphotericin B therapy
Clinical biochemistry, Vol.50(16-17), pp.967-971
11/2017
DOI: 10.1016/j.clinbiochem.2017.05.016
PMID: 28578095
Abstract
Hypophosphatemia is commonly observed in critically ill patients. Inorganic phosphorus is quantified by spectrophotometric measurement of a phosphomolybdate complex, a method with multiple documented interferents. Our clinical laboratory was contacted to investigate a case of asymptomatic hypophosphatemia in a patient receiving high-dose liposomal amphotericin B therapy (L-AMB).
In vitro experiments were performed by spiking L-AMB into residual plasma specimens. Phosphate was measured on the Beckman Coulter AU and Ortho Diagnostics Vitros instruments.
When measured on the AU, phosphate in plasma with approximately 250mcg/mL of L-AMB demonstrated a median negative bias of 3.45mg/dL relative to unspiked samples. In contrast, Vitros phosphate measurements demonstrated excellent agreement for specimens with and without L-AMB (median bias −0.2mg/dL).
High L-AMB concentrations induced a significant negative bias on phosphate measured by the AU assay, but did not affect the Vitros assay. Laboratorians and clinicians should be aware of this phenomenon in patients receiving L-AMB who develop unexplained hypophosphatemia.
•We document a previously unrecognized association between L-AMB therapy and pseudohypophosphatemia on the Beckman Coulter AU.•Phosphate measurements in plasma with 250mcg/mL L-AMB demonstrated a median bias of −3.45mg/dL compared to controls.•The Vitros method appears to be unaffected by high-dose L-AMB.•Clinicians and laboratorians should be aware of this phenomenon in order to avoid inappropriate phosphate repletion.
Details
- Title: Subtitle
- Pseudohypophosphatemia associated with high-dose liposomal amphotericin B therapy
- Creators
- James A Mays - University of WashingtonDina N Greene - University of WashingtonAnne Poon - University of WashingtonAnna E Merrill - University of Washington
- Resource Type
- Journal article
- Publication Details
- Clinical biochemistry, Vol.50(16-17), pp.967-971
- DOI
- 10.1016/j.clinbiochem.2017.05.016
- PMID
- 28578095
- NLM abbreviation
- Clin Biochem
- ISSN
- 0009-9120
- eISSN
- 1873-2933
- Publisher
- Elsevier Inc
- Grant note
- DOI: 10.13039/100007812, name: University of Washington
- Language
- English
- Date published
- 11/2017
- Academic Unit
- Pathology; Injury Prevention Research Center
- Record Identifier
- 9984186644602771
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