Clinical determination of 17-hydroxyprogesterone in serum by LC-MS/MS: comparison to Coat-A-Count RIA method.
17alpha-Hydroxyprogesterone is a metabolic precursor of cortisol; elevated levels of 17alpha-hydroxyprogesterone are indicative of congenital adrenal hyperplasia. Traditional determination by immunoassay is plagued by poor antibody specificity, resulting in significant interferences. This study explores an LC-MS/MS method for the quantitation of 17OHP in serum. Deuterated 17alpha-hydroxyprogesterone was added as internal standard, followed by solid-phase extraction, HPLC separation with a C16-amide reverse-phase column with run time of 7 min, and quantification by MS/MS (positive electrospray ionisation) in the selected reaction monitoring mode (SRM). Transitions monitored were 331>109 for the analyte and 339>113 for the deuterated internal standard. Intra-assay precision (%R.S.D.) was 7.4% at 7 nmol/L, inter-assay precision (%R.S.D.) at 2, 7 and 27 nmol/L was 15.4, 10.0 and 7.9% and accuracy at 0.9 nmol/L was 100%. The method was linear from 0.156 to 80 nmol/L. Lower limit of quantitation was 0.2 nmol/L, providing meaningful data for patients within normal range as well as those with elevated levels.
Etter
Michele L
ML
Saskatchewan Health Provincial Laboratory, 3211 Albert Street, Regina, SK, Canada S4S 5W6.
Eichhorst
Jeff
J
Lehotay
Denis C
DC
D019326:17-alpha-Hydroxyprogesterone / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D011863:Radioimmunoassay / Q000379:methods*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D019326:17-alpha-Hydroxyprogesterone