Use of an automated ACTH assay for the diagnosis of pituitary and adrenal-related diseases

Objective: To evaluate Liaison Diasorin's automated ACTH assay. Design: We investigated the limit of quantification (LOQ) and simulated the usage of the analyzer using our ACTH results database. Results: The LOQ was close to the cut-off determining Cushing's syndrome ACTH dependency. 25% concentrations of normal subjects were lower than the LOQ. Although biased, the results were concordant with those of an IRMA assay. Conclusion: This assay is not sensitive enough to diagnose ACTH-independent Cushing's syndrome. (C) 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.