Objectives: Differences in measurement of FGF 23 in serum, EDTA plasma and heparin plasma Method: Fully automated neasurement of intact FGF 23 by DiaSorin LIAISON FGF 23 method. The samples of serum, EDTA plasma and heparin plasma were used.
Results: Serum values of FGF 23 are ca 3 times lower than EDTA and heparin plasma. Values in EDTA and heparin plasma are comparable.
Phosphate values are comparable in serum and both plasma samples, but Ca values cannot be determined by phohotometric method in EDTA plasma. In hemodialyzed patients are all results higher than upper reference limit, often on 2-3 times higher numerical order and in very wide range.
Patients after transplantation had in approximately 50 % cases FGF 23 values above upper reference limit. Discussion: There is possible to use for FGF 23 measurement alternatively EDTA or heparin plasma samples.
Using of EDTA plasma samples, recommended by producer requires separately collected sample for Ca measurement.