2016 ACVIM Forum Research Abstract Program

Precision of the screening assay was determined using 3 samples (negative, low positive, and high positive). The intra-assay coefficient of variation (CV) ranged from 3.9% to 7.9% while the interassay CV ranged from 6.0% to 8.6%. For the confirmatory assay, the same low positive and high positives samples were used demonstrating an intra-assay CV which ranged from 3.0% to 4.7% and an inter-assay CV between 7.4% and 9.7%. No interference was observed for either protocol at bilirubin, hemoglobin, and lipid concentrations up to 14.4 mg/dl, 550 mg/dl, and 6.4 OD 660 nm , respectively. The analytical sensitivity for FeLV p27 antigen was established at 1.7 ng/mL for inactivated whole FeLV and at 1.0 ng/mL for purified recombinant FeLV p27. Discriminating analytical specificity was demonstrated based on the absence of cross-reactivity to related retrovirus antigen from murine leukemia virus and Feline RD-114. Overall, the assay exhibited 100% diagnostic accuracy in 83 patient samples (n = 63 negative; n = 20 positive) with FeLV status defined on the combined basis of PCR (FeLV RealPCR; IDEXX Laboratories, Inc.) and independent ELISA (ViraCHEK FeLV; Zoetis, Inc.).