Felten S, Luetenegger C, et al. Sensitivity and specificity of a real-time reverse transcriptase polymerase chain reaction detecting feline coronavirus mutations in effusion and serum/plasma of cats to diagnose feline infectious peritonitis. BMC Vet Res. 2017 Aug 2;13(1):228.
Feline coronavirus (FCoV) is the agent of feline infectious peritonitis, a lethal disease of cats. Most cats with FCoV infection do not experience illness, but a small percentage develop FIP. Disease production has been associated with the presence of mutations in a virus gene, the spike protein gene. The aim of this study was to evaluate sensitivity and specificity of a real-time reverse transcriptase polymerase chain reaction (RT-PCR) specifically designed to detect FCoV spike gene mutations at two nucleotide positions. It was hypothesized that this test would correctly discriminate feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV).
Of 63 cats tested, 38 were confirmed as having FIP. Twenty-five control cats were identified as having diseases other than FIP. Effusion and/or serum/plasma samples were examined by real-time RT-PCR targeting the two FCoV spike gene fusion peptide mutations M1058 L and S1060A using an allelic discrimination approach. Sensitivity, specificity, negative and positive predictive values were calculated.
FIPV was detected in the effusion of 25/59 cats, one of them being a control cat with chronic kidney disease. A mixed population of FIPV/FECV was detected in the effusion of 2/59 cats; all of them had FIP. RT-PCR was negative or the pathotype could not be determined in 34/59 effusion samples. In effusion, sensitivity was 68.6% (95% CI 50.7–83.2), specificity was 95.8% (95% CI 78.9–99.9). No serum/plasma samples were positive for FIPV. The authors concluded that although specificity of the test in effusions was high, one false positive result occurred. The use of serum/plasma cannot be recommended due to a low viral load in blood. (MK)
Doenges SJ, Weber K, et al. Comparison of real-time reverse transcriptase polymerase chain reaction of peripheral blood mononuclear cells, serum and cell-free body cavity effusion for the diagnosis of feline infectious peritonitis. J Feline Med Surg. 2017 Apr;19(4):344-350.