Peer-reviewed veterinary case report
Tryptophan changes in cats infected with FIV virus
By Kenny, Martin J et al.·Published in Journal of veterinary internal medicine·2007·School of Clinical Veterinary Sciences, United Kingdom·View original on PubMed →
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Original publication title: Altered tryptophan metabolism in FIV-positive cats.
- Species:
- cat
Plain-English summary
A group of 235 cats, including 120 with feline immunodeficiency virus (FIV), were tested for levels of tryptophan, an important amino acid. The FIV-positive cats had much lower levels of tryptophan and higher levels of kynurenine, a byproduct of tryptophan breakdown, compared to healthy cats. This suggests that FIV causes changes in how tryptophan is processed in the body. Researchers believe that dietary changes or medications that boost tryptophan levels could help improve the health of cats with FIV, similar to treatments used in humans with AIDS.
People also search for: cat FIV treatment · low tryptophan in cats · dietary support for FIV-positive cats
Abstract
BACKGROUND: Feline immunodeficiency virus (FIV) is analogous to human immunodeficiency virus, the causative agent of human acquired immunodeficiency syndrome (AIDS). In AIDS patients, a progressive reduction in serum tryptophan concentration occurs because of activation of an inducible tryptophan degradation pathway mediated by elevated lamda-interferon production. HYPOTHESIS: Cats infected with FIV have increased tryptophan catabolism evidenced by reduced circulating concentrations of tryptophan and increased concentrations of the tryptophan catabolite kynurenine. ANIMALS: Convenience sample of 235 cats submitted for diagnostic FIV serology (115 FIV-negative and 120 FIV-positive cats). METHODS: Retrospective, cross-sectional study. Serum was assayed for tryptophan and kynurenine using a high performance liquid chromatography assay with fluorescence and ultraviolet detection, respectively. RESULTS: Tryptophan and kynurenine concentrations were log-normally distributed. Geometric mean concentrations were: tryptophan: FIV-positive 30.6 microM (95% CI: 26.8 34.8 microM), FIV-negative 48.9 [microM (95% CI: 43.6-54.9 microM) (P < .001); kynurenine: FIV-positive 22.7 microM (95% CI: 25.5-10.9 microM), FIV-negative 9.9 microM (95% CI: 20.3-9.03 microM) (P < .001). The ratio of kynurenine to tryptophan was: FIV-positive 4.93 (95% CI: 5.62-4.32), FIV-negative 1.34 (95% CI: 1.53 1.17) (P < .0001). CONCLUSIONS AND CLINICAL IMPORTANCE: Serum tryptophan concentration was significantly lower and serum kynurenine concentration was significantly higher in FIV-positive cats. The kynurenine: tryptophan ratio was >3-fold higher in FIV-positive animals, indicating increased tryptophan catabolism in this group. Dietary or pharmacologic intervention to support serum tryptophan concentrations has been shown to be clinically useful in humans with AIDS and might be applicable to cats with FIV infection.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/17552465/