Relationship between Uveal Inflammation and Viral Detection in 30 Cats with Feline Infectious Peritonitis
Mariano Carossino,
Fabio Del Piero,
Jeongha Lee,
David B. Needle,
Jonathan M. Levine,
Ronald R. Riis,
Roger Maes,
Annabel G. Wise,
Keenan Mullaney,
Jacqueline Ferracone,
Ingeborg M. Langohr
Affiliations
Mariano Carossino
Department of Pathobiological Sciences and Louisiana Animal Disease Diagnostic Laboratory, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803, USA
Fabio Del Piero
Department of Pathobiological Sciences and Louisiana Animal Disease Diagnostic Laboratory, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803, USA
Jeongha Lee
Department of Pathobiological Sciences and Louisiana Animal Disease Diagnostic Laboratory, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803, USA
David B. Needle
New Hampshire Veterinary Diagnostic Laboratory, College of Life Sciences and Agriculture, University of New Hampshire, Durham, NH 03824, USA
Jonathan M. Levine
Department of Small Animal Clinical Sciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77845, USA
Ronald R. Riis
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA
Roger Maes
Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
Annabel G. Wise
Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
Keenan Mullaney
Washtenaw Technical Middle College, Ann Arbor, MI 48105, USA
Jacqueline Ferracone
PennVet New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA 19348, USA
Ingeborg M. Langohr
Department of Pathobiological Sciences and Louisiana Animal Disease Diagnostic Laboratory, Louisiana State University School of Veterinary Medicine, Baton Rouge, LA 70803, USA
Feline infectious peritonitis (FIP) virus is the most common infectious cause of uveitis in cats. Confirmatory diagnosis is usually only reached at postmortem examination. The relationship between the histologic inflammatory pattern, which depends on the stage of the disease, and the likelihood of detection of the viral antigen and/or RNA has not been investigated. We hypothesized that viral detection rate by either immunohistochemistry, in situ hybridization or RT-qPCR is dependent upon the predominant type of uveal inflammatory response (i.e., pyogranulomatous vs. plasmacytic). Thus, the aims of this study were to evaluate cases of FIP-induced uveitis, localize the viral antigen and RNA, and assess the relationship between the inflammatory pattern (macrophage- vs. plasma cell-rich) and the likelihood of detecting the FIP antigen and/or RNA. We evaluated 30 cats with FIP-induced uveitis. The viral antigen and/or RNA were detected within uveal macrophages in 11/30 cases, of which 8 tested positive by RT-qPCR. Correlation analysis determined a weak to moderate but significant negative correlation between the degree of plasmacytic uveal inflammation and the likelihood of detecting the FIP antigen and RNA. This study suggests that predominance of plasmacytic inflammation in cases of FIP uveitis reduces the odds of a confirmatory diagnosis through the viral detection methods available.
