Calibration and evaluation of routine methods by serum certified reference material for aldosterone measurement in blood.
We attempted to study the standardization of aldosterone measurement in blood. The serum certified reference material (serum CRM) was established by spiking healthy human serum with pure aldosterone. ID-LC/MS/MS as a reference measurement procedure was performed by using the serum CRM. LC-MS/MS as a comparison method (CM) was routinely used for clinical samples, and the values with and without calibration by the serum CRM were compared. The serum CRM demonstrated similar reactivity with peripheral blood plasma as clinical samples in routine methods (RM) of RIA, ELISA, and CLEIA. In comparison between RM and CM, the results in regression analysis indicated that the range of the correlation coefficient (r) was 0.913 - 0.991, the range of y intercept was 0.9 - 67.3 pg/mL and the range of slope was 0.869 - 1.174. The values by RM in 100 - 150 pg/mL for the diagnostic level, had a significant calibration effect, and the relative difference between calibrated value in RM and result by CM was within ±20%. Furthermore, the calibrated value using the serum CRM was 10,187 pg/mL, which corresponds to measured value of 14,000 pg/mL using RIA for the adrenal venous sampling. Measured values between plasma and serum as a sample for the aldosterone measurement from clinical samples showed no significant differences. In conclusion, we succeeded to prepare the certified reference material of aldosterone for RM. Then, we can accurately calculate corrected values by using our equation for four RMs of determination of aldosterone.
Endocrinology and Diabetes Center, Yokohama Rosai Hospital, Yokohama, Japan.
Tetsuo
T
Nishikawa
Masao
M
Omura
Migaku
M
Kawaguchi
Akiko
A
Takatsu
Fumitoshi
F
Satoh
Sadayoshi
S
Ito
Isao
I
Kurihara
Hiroshi
H
Itoh
Toshihiko
T
Yanase
Hirotaka
H
Shibata
Yutaka
Y
Oki
Mitsuhide
M
Naruse
Keiko
K
Sakurai
Hidehiko
H
Sasamoto
Katsuhiko
K
Kuwa
D000450:Aldosterone / Q000032:analysis / Q000097:blood*; D001774:Blood Chemical Analysis / Q000592:standards*; D002138:Calibration; D002853:Chromatography, Liquid; D003955:Diagnostic Tests, Routine / Q000592:standards*; D006801:Humans; D010912:Pituitary-Adrenal Function Tests / Q000379:methods / Q000592:standards*; D011933:Reagent Kits, Diagnostic / Q000592:standards; D012015:Reference Standards; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry
D011933:Reagent Kits, Diagnostic; D000450:Aldosterone