Investigating the pathogenesis of high-serum gamma-glutamyl transferase activity in Thoroughbred racehorses: A series of case-control studies.
Equine Vet J
; 54(1): 39-51, 2022 Jan.
Article
em En
| MEDLINE
| ID: mdl-33555643
ABSTRACT
BACKGROUND:
High-serum γ-Glutamyl Transferase (GGT) activity has been associated with and thought to be a marker of maladaptation to training and possibly poor performance in racehorses, but the cause is unknown.OBJECTIVES:
To investigate possible metabolic and infectious causes for the high GGT syndrome. STUDYDESIGN:
Pilot case-control study and nested case-control study.METHODS:
The case-control study in 2017 included 16 horses (8 cases and 8 controls with median [range] serum GGT 82 [74-148] and 22 [19-28] IU/L, respectively) from the same stable. In 2018, similar testing was performed in a nested case-control study that identified 27 case (serum GGT 50 ≥ IU/L)-control pairs from three stables for further testing. Serum liver chemistries, selenium measurements, viral PCR and metabolomics were performed.RESULTS:
No differences were found in frequency of detection of viral RNA/DNA or copy numbers for equine hepacivirus (EqHV) and parvovirus-hepatitis (EqPV-H) between cases and controls. Mild increases in hepatocellular injury and cholestatic markers in case vs control horses suggested a degree of liver disease in a subset of cases. Metabolomic and individual bile acid testing showed differences in cases compared with controls, including increased abundance of pyroglutamic acid and taurine-conjugated bile acids, and reduced abundance of Vitamin B6. Selenium concentrations, although within or above the reference intervals, were also lower in case horses in both studies. MAINLIMITATIONS:
Observational study design did not allow us to make causal inferences.CONCLUSIONS:
We conclude that high GGT syndrome is likely a complex metabolic disorder and that viral hepatitis was not identified as a cause for this syndrome in this cohort of racehorses. Our results support a contribution of oxidative stress and cholestasis in its pathophysiology.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Infecções por Parvoviridae
/
Gama-Glutamiltransferase
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Doenças dos Cavalos
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos