Analytical and clinical validation of a radioimmunoassay for the measurement of 1,25 dihydroxy vitamin D.
OBJECTIVE
The analytical and clinical validation of the DiaSorin 1,25 dihydroxyvitamin D RIA is described.


METHODS
The analytical parameters assessed included analytical sensitivity, dilution linearity, intra- and inter-assay precision, recovery, specificity, and interference studies. Where appropriate, assessments were performed according to NCCLS guidelines. The clinical validation assessed normal individuals and end-stage renal disease patients.


RESULTS
The analytical sensitivity of the assay is < 2.0 pg/mL or < 4.8 pM. The assay is specific for both 1,25 dihydroxyvitamin D2 and D3. Recovery ranged from 97% to 108% for spiked samples. Intra-assay precision, as %CV, ranged from 7% to 11%, while inter-assay precision was 12% to 15%. No interference was observed from bilirubin, cholesterol, hemoglobin, or triglycerides. Clinical validation demonstrated complete discrimination between normal and ESRD populations.


CONCLUSIONS
These data demonstrate that the DiaSorin 1,25 (OH)(2) vitamin D RIA is a robust, accurate, and precise tool for the assessment of 1,25 (OH)(2) vitamin D.
Clive
Diana R
DR
DiaSorin, Inc., Stillwater, MN 55082, USA.
Sudhaker
D
D
Giacherio
Donald
D
Gupta
Manjula
M
Schreiber
Martin J
MJ
Sackrison
James L
JL
MacFarlane
Gordon D
GD
D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood; D016014:Linear Models; D011863:Radioimmunoassay / Q000379:methods*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013696:Temperature; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood*
D014807:Vitamin D; C097949:1,25-dihydroxyvitamin D