Related Experiment Videos
Spuriously elevated inorganic phosphate level in a multiple myeloma patient
B Barutçuoglu1, Z Parildar, I Mutaf
1Department of Clinical Biochemistry, Ege University Faculty of Medicine, Izmir, Turkey.
Clinical and Laboratory Haematology
|August 2, 2003
Summary
Pseudohyperphosphatemia in multiple myeloma is a false lab result caused by high paraprotein levels. Testing deproteinized serum samples is crucial for accurate phosphate measurement in these patients.
Area of Science:
- Clinical Chemistry
- Hematology
- Oncology
Background:
- Multiple myeloma is a plasma cell malignancy.
- Hyperphosphatemia is a potential complication, but can be falsely elevated.
- Monoclonal immunoglobulins can interfere with laboratory assays.
Observation:
- A patient with IgG multiple myeloma presented with pseudohyperphosphatemia.
- The patient lacked clinical signs of true hyperphosphatemia.
- Serum phosphate levels normalized after deproteinization.
Findings:
- The elevated phosphate was spurious, caused by paraprotein interference.
- Monoclonal immunoglobulin interfered with the molybdic reagent used for phosphate determination.
- Increased optical density due to paraprotein caused the falsely high phosphate reading.
Implications:
- Marked hyperphosphatemia in multiple myeloma warrants testing on deproteinized samples.
- Recognizing pseudohyperphosphatemia prevents diagnostic confusion and unnecessary tests.
- Accurate phosphate levels are vital for optimal clinical management of multiple myeloma.