Histological assessment of β‐amyloid precursor protein immunolabelled rectal biopsies aids diagnosis of equine grass sickness

Abstract

Histological assessment of β-APP immunolabelled rectal biopsies is more sensitive than conventional histological examination in EGS diagnosis. Further validation is required before this technique can be advocated for use in clinical decision making.

A study of residual lesions in horses that recovered from clinical signs of chronic equine dysautonomia

“…Beta‐amyloid precursor protein increases in the perikarya of CCG neurons in acute and subacute ED and is thought to be involved in the pathogenesis of ED . The increase in BAPP staining is also of value in the antemortem diagnosis of acute and subacute ED, and there is increased expression in rectal biopsies from ED‐affected horses . In contrast, we found no evidence of significantly greater BAPP staining at any site in the ED cases compared with controls; therefore, accumulation of BAPP does not appear to be a feature of recovered ED cases.…”

“…All sections were counterstained with hematoxylin. The immunohistochemistry (IHC) methods have been previously validated for equine tissues in our laboratory …”

Highlights of recent clinically relevant papers

“…In this study Rachel Jago and colleagues in the UK assessed β‐amyloid precursor protein (β‐APP) immunolabelled rectal biopsies as an aid for diagnosis of equine grass sickness .…”

Science‐in‐brief: Clinical highlights from BEVA Congress 2016

“…Rachel Jago from the Royal (Dick) School of Veterinary Studies and Roslin institute of Edinburgh, showed that ß‐amyloid precursor protein (ß‐APP) immunoreactivity was increased in neuronal perikarya and axons in sections of cranial cervical ganglia, ileum and rectum from EGS horses compared with controls. Dr Jago developed a promising antemortem diagnostic test for EGS based on histological assessment of immunolabelled ß‐APP on rectal biopsies . Furthermore, a cross‐sectional study of chronic cases of EGS (cEGS) based on postal questionnaires reported that the most prevalent signs observed by owners were muscle fasciculations, hyperhidrosis and inappetance/anorexia.…”