Faculty Collaboration Database

A new immunoradiometric assay for corticotropin evaluated in normal subjects and patients with Cushing's syndrome. Clin Chem 1989 Apr;35(4):596-600

Date

04/01/1989

Pubmed ID

2539271

DOI

10.1093/clinchem/35.4.596

Scopus ID

2-s2.0-0024601728 (requires institutional sign-in at Scopus site)   143 Citations

Abstract

We evaluated a new, commercially available two-site immunoradiometric assay (IRMA) for corticotropin (ACTH) in human plasma. The precision and detection limit were an improvement over radioimmunoassay (RIA). Addition of ACTH 1-24 or ACTH 18-39 to plasma containing ACTH 1-39 resulted in a decrease in measured ACTH. Results by both IRMA and RIA are reported and compared for normal subjects, patients with Cushing's disease, and patients with ectopic ACTH. Effects of administering dexamethasone, metyrapone, ACTH 1-24, and corticoliberin were evaluated. The present assay is more sensitive, specific, and reproducible than RIA. The presence of fragments of ACTH or "big" ACTH that are reactive in RIA may lead to artifactually low ACTH concentrations by IRMA. Therefore, RIA may still be necessary for differential diagnosis of ectopic ACTH syndromes. However, the IRMA is an improvement for evaluating pituitary--adrenal function in patients with low concentrations of ACTH in plasma.

Author List

Raff H, Findling JW

Authors

James W. Findling MD Professor in the Medicine department at Medical College of Wisconsin
Hershel Raff PhD Professor in the Academic Affairs department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

ACTH Syndrome, Ectopic
Adrenocorticotropic Hormone
Adult
Corticotropin-Releasing Hormone
Cosyntropin
Cushing Syndrome
Dexamethasone
Humans
Hydrocortisone
Immunoassay
Male
Metyrapone
Quality Control
Radioimmunoassay