A direct, rapid and highly specific fluoroimmunoassay for determining serum levels of 17-hydroxyprogesterone has been developed. It is based on the use of a sheep antiserum covalently coupled to magnetisable particles and fluorescein-labelled steroid. Sodium salicylate is employed to eliminate interference from endogenous binding proteins in serum. The sensitivity of 0·5 nmol/L is adequate for clinical purposes. Analytical recovery, linearity and precision are satisfactory and the results obtained correlate closely with those of an established radioimmunoassay using 3H-labelled steroid and the same antiserum after initial sample extraction and chromatography. The values found for serum from normal adult subjects ranged from 1·0 to 12·6 nmol/L while those from treated and untreated patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency were 1·5 to 190 and 28·0 to 655 nmol/L, respectively.
References
1.
JanneOPerheentupaJViinikkaLVihkoRV. Plasma pregnenolone. progesterone, 17-hydroxyprogesterone, testosterone and 5 α-dihydrotestosterone in different types of congenital adrenal hyperplasia. Clin Endocrinol1975; 4: 39–48.
2.
YoussefnejadianEDavidR. Early diagnosis of congenital adrenal hyperplasia by measurement of 17-hydroxyprogesterone. Clin Endocrinol1975; 4: 451–4.
3.
StrottCAYoshimiTLipsettMB. Plasma progesterone and 17-hydroxyprogesterone in normal men and children with congenital adrenal hyperplasia. J Clin Invest1969; 48: 930–9.
4.
LippeBMLa FranchiSHLavinNSerum 17 α-hydroxyprogestergone, progesterone, estradiol and testosterone in the diagnosis and management of congenital adrenal hyperplasia. J Pediatr1974; 85: 782–7.
5.
WalkerRFReadGFHughesIARiad-FahmyD. Radioimmunoassay of 17α-hydroxyprogesterone in saliva, parotid fluid, and plasma of congenital adrenal hyperplasia. Clin Chem1979; 25: 542–5.
6.
YoussefnejadianEFlorensaECollinsWPSommervilleIF. Radioimmunoassay of 17-hydroxyprogesterone. Steroids1972; 20: 773–88.
7.
PowellJEStevensVC. Simple radioimmunoassay of five unconjugated ovarian steroids in a single sample of serum or plasma. Clin Chem1973; 19: 210–5.
8.
Pham-Huu-TrungHTGourmelenMGirardF.The simultaneous assay of Cortisol and 17 α-hydroxyprogesterone in the plasma of patients with congenital adrenal hyperplasia. Acta Endocrinol, 1973; 74: 316–316.
9.
TeaNTCastanierMRogerMSchollerR. Simultaneous radioimmunoassay of plasma progesterone and 17-hydroxyprogesterone. Normal values in children, in men and in women throughout the menstrual cycle and in early pregnancy. J Steroid Biochem1975; 6: 1509–16.
10.
HughesIAWinterJSD. The application of a serum 170H-progesterone radioimmunoassay to the diagnosis and management of congenital adrenal hyperplasia. J Pediatr1976; 88: 766–73.
11.
VermeulenAVerdonckL. Radioimmunoassay of 17 β-hydroxy-5α-androstan-3-one, 4-andro-stene-3, 17-dione, dehydroepiandrosterone, 17-hydroxyprogesterone and progesterone and its application to human male plasma. J Steroid Biochem1976; 7: 1–10.
12.
BarronJLKewleyCMillarRPGrayP. A radioimmunoassay of 17-alpha-hydroxyprogesterone. S Afr Med J1980; 57: 497–500.
13.
JanneOApterDVihkoR. Assay of testosterone, progesterone and 17 α-hydroxyprogesterone in human plasma by radioimmunoassay after separation on hydroxyalkoxypropyl Sephadex. J Steroid Biochem1974; 5: 155–62.
14.
JanoskiAHShulmanFCWrightGE. Selective 3-[O-carboxymethyl] oxime formation in steroidal 3,20-diones for hapten immunospecificity. Steroids1974; 23: 49–64.
15.
AbrahamGESwerdloffRSTulchinskyDRadioimmunoassay of plasma 17-hydroxyprogesterone. J Clin Endocrinol1971; 33: 42–6.
16.
ForestMG. Use of highly specific antibodies against 17 α-OH-progesterone in a simplified nonchromatographic RIA and in the simultaneous determination of four sex hormones in human plasma. Horm Res1976; 7: 260–73.
17.
WickingsEJ. Radioimmunoassay of 17-hydroxyprogesterone in serum with or without thin-layer chromatographic purification. Horm Res1975; 6: 78–84.
18.
SchoneshoferMFennerADulceHJ. Assessment of eleven adrenal steroids from a single serum sample by combination of automatic high-performance liquid chromatography and radioimmunoassay (HPLC-RIA). J Steroid Biochem1981; 14: 377–86.
19.
HamiMRosierARabinowitzD. A nonchromatographic radioimmunoassay for 17 α-hydroxyprogesterone. J Clin Endocrinol Metab1975; 40: 863–7.
20.
DavilaNRuddBTMorrisRA simple procedure for the radioimmunoassay of 17-hydroxyprogesterone in serum: comparison with an immunological purification technique. Ann Clin Biochem1980; 17: 31–7.
21.
DyasJReadGFGuha-MaulikTA rapid assay for 17 α-OH-progesterone in plasma, saliva and amniotic fluid using a magnetisable solid-phase antiserum. Ann Clin Biochem1984; 21: 417–24.
22.
YeoKHJWhitauWJ. 125I Radioimmunoassay for 17 α-hydroxyprogesterone in plasma, for diagnosing and managing congenital adrenal hyperplasia. Clin Chem1985; 31: 454–6.
23.
FosterLBDunnRT. Single antibody technique for radioimmunoassay of Cortisol in unextracted serum or plasma. Clin Chem1974; 2: 365–8.
24.
HufnerMHeschRD. A comparison of different compounds for TBG-blocking used in radioimmunoassay for tri-iodothyronine. Clin Chim Acta1973; 44: 101–7.
25.
KaneJW. Use of sodium salicylate as a blocking agent for cortisol-binding globulin in a radioimmunoassay for Cortisol on unextracted plasma. Ann Clin Biochem1979; 16: 209–12.
26.
PourfarzanehMWhiteGWLandonJSmithDS. Cortisol directly determined in serum by fluoroimmunoassay with magnetizable solid phase. Clin Chem1980; 26: 730–3.
27.
RatcliffeWACorrieETDalzielAHMacphersonJS. Direct 125I-radioligand assays for serum progesterone compared with assays involving extraction of serum. Clin Chem1982; 28: 1314–8.
28.
McConwayMGChapmanRS. Development and evaluation of a simple, direct, solid-phase radioimmunoassay of serum Cortisol from readily available reagents. Clin Chim Acta1986; 158: 59–70.
29.
SethJBrownLM. A simple radioimmunoassay for plasma Cortisol. Clin Chim Acta1978; 86: 109–20.
30.
SmithDSAl-HakiemMHHLandonJ. A review of fluoroimmunoassay and immunofluorometric assay. Ann Clin Biochem1981; 18: 253–74.
31.
PourfarzanehMKamelRSLandonJDawesCC. The use of magnetisable particles in solid phase immunoassay. In GlickD, ed. Methods in Biochemical Analysis.Vol 28. New York: John Wiley, 1982; 281–300.
32.
El-GamalBALandonJAbukneshaRAProduction and characterisation of antisera to 17-hydroxyprogesterone. J Steroid Biochem1987; 26: 375–82.
33.
RodbardD. Statistical estimation of the minimal detectable concentration (‘sensitivity’) for radioligand assays. Anal Biochem1978; 90: 1–12.
