Short Communication: Identification of equine corticotropin-like intermediate lobe peptide (CLIP) binding to an adrenocortipcotrophic hormone (ACTH) assay capture antibody

Knowles, Edward; Hyde, Cali; Harris, Patricia; Elliott, Jonathan; Menzies-Gow, Nicola

Abstract

A chemiluminescent immunoassay is commonly employed to measure adrenocorticotrophic hormone (ACTH) concentrations to assist pituitary pars intermedia dysfunction diagnosis. In a previous study, seasonally dependent assay cross-reactivity to endogenous equine corticotropin-like intermediate lobe peptide (CLIP, ACTH 18-39) was suspected. The present study aimed to demonstrate binding of endogenous equine CLIP to the capture antibody of the ACTH chemiluminescent immunoassay. Liquid chromatography – mass spectrometry (LCMS) methods were optimised to identify selected ions from synthetic human ACTH, α-melanocyte stimulating hormone (α-MSH, ACTH 1-17) and CLIP. Synthetic ACTH and CLIP bound to the capture antibody of the chemiluminescent ACTH assay, but α-MSH did not. Equine endogenous CLIP was detected by LCMS in pony plasma taken in the autumn and could be eluted from the capture antibody of the ACTH chemiluminescent immunoassay.. Further research is required to enable quantification of CLIP. Equine CLIP may alter measured ACTH concentrations in vivo.

Citation

Knowles, E., Hyde, C., Harris, P., Elliott, J., & Menzies-Gow, N. (2023). Short Communication: Identification of equine corticotropin-like intermediate lobe peptide (CLIP) binding to an adrenocortipcotrophic hormone (ACTH) assay capture antibody. Domestic Animal Endocrinology, https://doi.org/10.1016/j.domaniend.2023.106785

• Journal Article Type: Article
• Acceptance Date: Jan 10, 2023
• Publication Date: Apr 1, 2023
• Deposit Date: Nov 25, 2022
• Publicly Available Date: Apr 26, 2023
• Print ISSN: 0739-7240
• Publisher: Elsevier
• Peer Reviewed: Not Peer Reviewed
• DOI: https://doi.org/10.1016/j.domaniend.2023.106785
• Publisher URL: https://www.sciencedirect.com/science/article/abs/pii/S0739724023000012