title: Serum calcitriol concentrations measured with a new direct automated assay in a large population of adult healthy subjects and in various clinical situations.
abstract: The measurement of calcitriol [1,25(OH2)D], is important for the differential diagnosis of several disorders of calcium/phosphorus metabolism but is time-consuming and tricky. We measured serum calcitriol with a new automated direct assay on the Liaison XL platform in 888 healthy French Caucasian subjects aged 18-89 years, 32 patients with a surgically-proven PHPT, 32 pregnant women at the end of the first and at the end of the third trimester, and 24 dialysis patients before and after one year of supplementation with vitamin D3 or placebo. The mean calcitriol concentration (±SD) in the healthy population was 52.9±14.5 ng/L with a 95% CI interval of 29-83.6 ng/L. In PHPT patients, calcitriol concentration was 81.6±29.0 ng/L, 15 of them (46.9%) having a concentration >83.6 ng/L. In pregnant women, calcitriol was 80.4±26.4 ng/L at the end of the first trimester, and 113.1±33.0 ng/L at the end of the third trimester, 12 (37.5%) and 26 (81.3%) of them having a calcitriol concentration >83.6 ng/L at the first and third trimesters respectively. In 14 dialysis patients, calcitriol was 9.5±7.7 ng/L and rose to 19.3 ng/L after one year of supplementation with 50,000 IU vitamin D3/month. In 10 other dialysis patients, calcitriol was 9.9±2.9 ng/L and remained stable (12.4±3.7 ng/L) after one year of placebo. In conclusion, this new automated calcitriol assay, in addition to presenting excellent analytical performances, gives the expected variations in patients compared to "normal" values obtained in an extensive reference population.
authors.affiliation: Service des explorations fonctionnelles, Necker-Enfants malades University hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), Paris, France. Electronic address: Jean-claude.souberbielle@nck.aphp.fr.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Souberbielle
authors.affiliation: Clinical Chemistry Department, Sart Tilman University Hospital, Liège, Belgium.
authors.forename: Etienne
authors.initials: E
authors.lastname: Cavalier
authors.affiliation: Nephrology and Dialysis Department, Sart Tilman University Hospital, Liège, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Delanaye
authors.affiliation: Hormonology Laboratory, Pontchaillou University Hospital, Rennes, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Massart
authors.affiliation: Hormonology Laboratory, Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, Le Kremlin-Bicêtre F94275, France; Univ Paris-Sud, UMR S1185, Faculté de Médecine Paris-Sud, Le Kremlin-Bicêtre F-94276, France; INSERM U1185, Le Kremlin-Bicêtre F-94276, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Brailly-Tabard
authors.affiliation: Rheumatology Department, Cochin University Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), Paris, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Cormier
authors.affiliation: Clinical Chemistry Department, Cochin University Hospital, Assistance Publique des Hôpitaux de Paris (AP-HP), Paris, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Borderie
authors.affiliation: Obstetrics, Gynecology and Reproductive Medicine Department, Antoine Beclere Hospital, Paris Sud University, Assistance Publique-Hôpitaux de Paris (AP-HP), Clamart, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Benachi
authors.affiliation: Univ Paris-Sud, UMR S1185, Faculté de Médecine Paris-Sud, Le Kremlin-Bicêtre F-94276, France; INSERM U1185, Le Kremlin-Bicêtre F-94276, France; Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, Service d'Endocrinologie et des Maladies de la Reproduction and Centre de Référence des Maladies Endocriniennes Rares de la Croissance, Le Kremlin-Bicêtre F94275, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Chanson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001331:Automation / Q000379:methods*; D001774:Blood Chemical Analysis / Q000379:methods*; D002117:Calcitriol / Q000097:blood*; D015331:Cohort Studies; D005260:Female; D005602:France; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D055815:Young Adult
chemical_list: D002117:Calcitriol
keywords: Calcitriol; Dialysis; Pregnancy; Primary hyperparathyroidism; Reference values; Vitamin D