title: A bloodspot androstenedione assay suitable for home-monitoring of steroid replacement therapy in congenital adrenal hyperplasia.
abstract: A bloodspot assay has been developed using an antiserum raised against androstenedione-3-carboxymethyloxime-bovine serum albumin (AD-3CMO-BSA) conjugate and 125I-AD-3CMO-histamine tracer. The method has a detection limit of 0.6 nmol/L blood and a working range from 0.6 to 40 nmol/L blood. The between-batch precision ranged from 8.4% to 23.3%. Bloodspot androstenedione (AD) concentrations were measured in 50 neonates (26 male, 24 female) and in 95 children (54 male, 41 female) aged 6 months to 18 years. No sex difference in concentrations was found in neonates, in pre-pubertal children up to 8 years of age, in pubertal children (males 8-16 years, females 8-14 years) or post-puberty. Bloodspot AD concentrations ranged from less than 0.6 to 2.7 nmol/L in neonates, less than 0.6 nmol/L in pre-pubertal children, 0.6-2.1 nmol/L in pubertal children and less than 0.6-4.6 nmol/L post-puberty. Daytime bloodspot profiles in 10 children on replacement therapy for congenital adrenal hyperplasia generally showed good correlation between 17 alpha-hydroxyprogesterone and AD concentrations (r = 0.928, P less than 0.001). Bloodspot AD profiles have advantages over 17 alpha-hydroxyprogesterone profiles for the assessment of the adequacy of glucocorticoid replacement therapy.
authors.affiliation: Regional Endocrine Unit, Southampton General Hospital, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Egan
authors.forename: P
authors.initials: P
authors.lastname: Betts
authors.forename: S
authors.initials: S
authors.lastname: Thomson
authors.forename: A M
authors.initials: AM
authors.lastname: Wallace
authors.forename: P J
authors.initials: PJ
authors.lastname: Wood
mesh_terms: D019326:17-alpha-Hydroxyprogesterone; D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000378:metabolism / Q000627:therapeutic use*; D000312:Adrenal Hyperplasia, Congenital / Q000097:blood* / Q000188:drug therapy; D000328:Adult; D000735:Androstenedione / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D006908:Hydroxyprogesterones / Q000097:blood; D007158:Immunologic Techniques; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008991:Monitoring, Physiologic; D012016:Reference Values; D012648:Self Care; D012680:Sensitivity and Specificity
chemical_list: D000305:Adrenal Cortex Hormones; D006908:Hydroxyprogesterones; D000735:Androstenedione; D019326:17-alpha-Hydroxyprogesterone