Detection of feline coronavirus RNA, spike gene mutations, and feline coronavirus antigen in macrophages in aqueous humor of cats in the diagnosis of feline infectious peritonitis

Sangl, Laura; Felten, Sandra; Matiasek, Kaspar; Dörfelt, Stefanie; Bergmann, Michele; Balzer, Hans-Jörg; Pantchev, Nikola; Leutenegger, Christian und Hartmann, Katrin (2020): Detection of feline coronavirus RNA, spike gene mutations, and feline coronavirus antigen in macrophages in aqueous humor of cats in the diagnosis of feline infectious peritonitis. In: Journal of Veterinary Diagnostic Investigation, Bd. 32, Nr. 4: S. 527-534

Abstract

Uveitis is common in cats, and is often a feature of feline infectious peritonitis (FIP). We evaluated 3 tools for detection of feline coronavirus (FCoV) in aqueous humor: 1) a7bgene reverse-transcription real-time PCR (7b-RT-rtPCR) assay to detect FCoV RNA, 2) a spike gene mutation RT-rtPCR (S-RT-rtPCR) assay to detect 2 point mutations in the spike gene of FCoV in cats positive by7b-RT-rtPCR, and 3) immunocytochemistry (ICC) for detection of FCoV antigen in aqueous humor macrophages. We studied 58 cats, including 31 cats with FIP and 27 control cats. FIP was excluded by postmortem examination and negative immunohistochemistry (IHC). Aqueous humor samples obtained postmortem were assessed using7b-RT-rtPCR in all cats, and positive samples were evaluated withS-RT-rtPCR. ICC evaluation of aqueous humor samples from 36 of the 58 cats was done using an avidin-biotin complex method and monoclonal anti-FCoV IgG 2A. Sensitivity, specificity, and negative and positive predictive values were calculated including 95% CIs.7b-RT-rtPCR had a specificity of 100.0% (95% CI: 87.2-100.0) and sensitivity of 35.5% (95% CI: 19.2-54.6). Specificity ofS-RT-rtPCR could not be determined because there were no FCoV7b-RT-rtPCR-positive samples in the control group. Sensitivity ofS-RT-rtPCR was 12.9% (95% CI 3.6-29.8). Sensitivity and specificity of ICC were 62.5% (95% CI: 40.6-81.2) and 80.0% (95% CI: 44.4-97.5), respectively. The combination of7b-RT-rtPCR and IHC could be useful in diagnosing FIP;S-RT-rtPCR did not add value;and ICC of aqueous humor samples cannot be recommended for the diagnosis of FIP.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Tiermedizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 1040-6387
• Sprache: Englisch