All work was performed at the Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. This work was funded by a BOF grant from Ghent University, Belgium. Results of this study were partially presented at the annual ACVIM forum in San Antonio, 2008.
Retinol-Binding Protein in Serum and Urine of Hyperthyroid Cats before and after Treatment with Radioiodine
Version of Record online: 11 AUG 2009
Copyright © 2009 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 23, Issue 5, pages 1031–1037, September/October 2009
How to Cite
Van Hoek, I., Meyer, E., Duchateau, L., Peremans, K., Smets, P. and Daminet, S. (2009), Retinol-Binding Protein in Serum and Urine of Hyperthyroid Cats before and after Treatment with Radioiodine. Journal of Veterinary Internal Medicine, 23: 1031–1037. doi: 10.1111/j.1939-1676.2009.0364.x
- Issue online: 1 SEP 2009
- Version of Record online: 11 AUG 2009
- Submitted August 14, 2008; Revised May 9, 2009; Accepted June 23, 2009.
- Tubular function;
- Urinary marker
Background: Retinol-binding protein (RBP) is suggested as a clinically useful marker of renal function in cats.
Hypothesis: Serum and urinary RBP concentrations in hyperthyroid (HT) cats differ from those in healthy (H) cats; radioiodine (131I) treatment influences serum and urinary RBP concentrations in HT cats.
Animals: Ten HT and 8 H cats.
Methods: RBP concentration was evaluated in feline serum and urine samples from a prospective study.
Results: There was a significant (P= .003) difference in the urinary RBP/creatinine (uRBP/c) ratios of H (−) and untreated HT (1.4 ± 1.5 × 10−2 μg/mg) cats. Serum total thyroxine concentration (1.8 ± 1.9 μg/dL, 24 weeks) and uRBP/c (0.6 ± 1.0 × 10−2 μg/mg, 24 weeks) decreased significantly (P < .001) in HT cats at all time points after treatment with 131I, and these variables were significantly correlated with one another (r= 0.42, P= .007). Serum RBP concentrations from HT cats (199 ± 86 μg/L) did not differ significantly (P= .98) from those of H cats (174 ± 60) and did not change after treatment with 131I (182 ± 124 μg/L, P= .80).
Conclusion and Clinical Importance: The presence of urinary RBP in HT cats is a potential marker of tubular dysfunction that is correlated to thyroid status, although it is independent of circulating RBP concentrations. The decreased uRBP/c combined with the absence of changes in serum RBP after treatment suggests that the suspected tubular dysfunction was partly reversible with treatment of 131I.