Analysis of 17 α-hydroxyprogesterone in bloodspots by liquid chromatography tandem mass spectrometry.

[congenital adrenal hyperplasia]

Monitoring of treatment for patients diagnosed with congenital adrenal hyperplasia (CAH ) can be performed by measuring the concentration of 17 α-hydroxyprogesterone (17 OHP ) in bloodspots collected on filter papers . A method is described here for measuring 17 OHP by liquid chromatography tandem mass spectrometry (LCMSMS ).17 OHP was extracted by liquid-liquid extraction and analysed by LCMSMS . The method was validated for sensitivity , specificity , linearity , recovery , ion suppression , precision and bias .The standard curve was linear from 0 to 400 nmol /L . Intra-assay %CVs were <10 and inter-assay %CVs were <15 over the range 10 -200 nmol /L . Limit of quantitation was 6 nmol /L . No ion suppression was detected . The only interfering compound detected was deoxycorticosterone , an intermediate steroid with the same molecular weight as 17 α-hydroxyprogesterone . The method was more accurate and precise than an existing radioimmunoassay . There was poor correlation between the two assays .We have developed a sensitive and specific assay suitable for quantitation of 17 OHP in bloodspots . This method performs better than radioimmunoassay and allows smaller samples to be used .