2018 ACVIM Forum Research Abstract Program: Seattle, Washington, June 14 - 15, 2018

show an appreciable reduction in T cell suppression. This may be due a short treatment period or due to the presence of un-activated lymphocytes as the cats were healthy. Future studies will evaluate the PD of MPA in clinically affected feline patients receiving MMF. Recent studies have highlighted the potential for CYP3A variation in susceptibility to several common phenotypes, including cancer. The objectives of this study were to analyze the sequencing of the canine CYP3A12 gene (NCBI accession NP_001003340) from thirteen clientowned dogs with MCT (Grade II-III) and to investigate the patterns of sequence variation that related to clinical response to therapy. Fisher'; s exact test was used to assess the correlation between SNPs and clinical response. All 13 patients receiving vinblastine showed signs of toxicity, including vomiting, anorexia, and thrombocytopenia. Three sets of point mutations were found in 6 patients with silent (T 12574 C, n = 1), missense (T 12564 G, n = 2) with a change in the amino acid (Ile169Leu), and frameshift mutations (Asp153Glufs, n = 3) in the coding sequences. Three of 6 patients that showed missense (n = 1) and frameshift mutations (n = 2) presented with recurrent MCT after vinblastine chemotherapy. This could represent a further step toward predicted the clinical response of anticancer chemotherapy. between patients with controlled clinical signs (n=127, 55%) versus those with uncontrolled disease (n=105, 45%). The most common diseases being treated were encephalitis (n = 84), immune-mediated hemolytic anemia or thrombocytopenia (n = 73), inflammatory bowel disease (IBD, n = 59), and other (n = 16, e.g. atopic dermatitis, anal furunculosis, uveitis). CsA peak levels for controlled (1119 ± 704 ng/ml) versus uncontrolled patients (994.84 ± 606 ng/ml) failed to demonstrate a statistical difference (P = 0.15). The t 1/2 of controlled patients (20 ± 40 hrs) was significantly longer than uncontrolled patients (11 ± 20 hrs) (P = 0.02). Significant variability was found in both peak CsA levels and t 1/2 . Co-treatment with prednisolone, leflunomide, and ketoconazole, and diseases also increased variability. Variability in CsA disposition supports the need for TDM to establish patient therapeutic range. The IDEXX-SDMA TM test is a non-invasive test being marketed for diagnosing and monitoring chronic kidney disease in cats and dogs.