2016 ACVIM Forum Research Abstract Program

Darbepoetin is an effective treatment for anemia secondary to CKD. A dosing interval of >21 days is not effective at maintaining a response to therapy. Further studies are needed to define the most effective dose. PRCA was a possible adverse event in 1/34 dogs (2.9%). Vitamin D-binding protein (VDBP) is the main carrier of vitamin D metabolites into circulation, and it is freely filtrated through glomerulus, and the complex VDBP-25-OH-vitamin D is uptaken by megalin-cubilin receptors in proximal tubules. Once the presence of VDBP in urine, it may indicate proximal tubular dysfunction/injury as well as interstitial tubular fibrosis. Also it still remains to be proven whether loss of VDBP in urine may lead to vitamin D deficiency and its contribution to the progression of chronic kidney disease (CKD) in dogs. The hypothesis and the aim of this study were to investigate whether VDBP could be previously detected in urine of dogs with CKD regardless of urinaryto-protein ratio (UPC) values, and it will be an early and specific marker of proximal tubular injury. Forty dogs according to IRIS staging of CKD (stage 1 n = 10; stage 2 n = 10; stage 3 n = 10; stage 4 n = 10) were enrolled, various breeds and age, and with no proteinuric-associated disease. Nine clinically healthy dogs, different breeds and age, composed the control group. Dogs with CKD were classified according to IRIS guidelines based on UPC as nonproteinuric (UPC<0.2), borderline proteinuric (UPC= 0.2 to 0.5) and proteinuric (UPC>0.5). Western blotting was performed to investigate VDBP in canine urine (Anti-Vitamin D Binding Protein antibody, ab95469, Abcam© 1:500). No urinary VDBP was detected in control dogs and UPC was 0.14 AE 0.04 (meanAESEM) and min= 0.028 and max= 0.41. In CKD dogs, urinary VDBP was observed since the early stages of CKD, stages 1 and 2, and the UPC was 0.39 AE 0.29; 0.02-3.01 and 0.33 AE 0.12; 0.14-1.14 (mean AESEM; min -max), respectively. In stage 1 CKD dogs, urinary VDBP was detected in 7 out of 10 dogs and in 4 of those 7 dogs, UPC was into the non-proteinuric range, 2 dogs in borderline range and only one was proteinuric. In stage 2 CKD dogs, VDBP in urine was noticed in 9 out of 10 CKD dogs and 5 of them had UPC < 0.2, one dog was in borderline (UPC= 0.42) and 3 dogs were slightly proteinuric (UPC of 0.67, 0.72 and 1.14). In CKD dogs in stage 3, UPC was 1.51 AE 0.54 (0.07-4.57) and VDBP in urine was immunodetected in 8 out of 10 dogs and in 3 of those 8 dogs, UPC was ≤ 0.28 and the left 5 dogs were proteinuric. All CKD dogs in stage 4 were proteinuric (UPC = 4.37 AE 0.47; 1.4-6.94) and showed VDBP in urine. In conclusion, the immunodetection of VDBP in urine noticed in the early stages of CKD in dogs, mainly in stages 1 or 2, associated with UPC into non or borderline proteinuric range, it reinforces that urinary VDBP could be a potential early marker of kidney injury as well as to detect the specific segment (proximal) of the nephron affected. Progressive interstitial nephritis (IN) is the primary cause of feline chronic kidney disease which is considered to be the leading cause of death in adult cats. The Crandell Rees feline kidney (CRFK) cell line is commonly used to grow feline herpesvirus 1 (FHV-1), calicivirus, and panleukopenia virus used in (FVRCP) vaccine production. Previous studies have shown that cats administered FVRCP vaccines parenterally develop antibodies against CRFK lysates and alpha enolase (glycolytic pathway enzyme in all mammal