Performances of different diagnostic tests for feline infectious peritonitis in challenging clinical cases

Methods: Twelve cases (four without FIP, eight with FIP) were retrospectively studied. Clinical findings, serum protein electrophoresis (SPE), analysis of the effusions (AE), antifeline coronavirus serology, serum concentration of alpha 1-acid glycoprotein (AGP) and histopathology were classified as consistent, doubtful or non-consistent with FIP. Sensitivity, specificity and concordance (kappa) with the final diagnosis were calculated. Results: Concordance was absent for serology (kappa=-0 center dot 08) and AE (kappa=-0 center dot 52), poor for histopathology (kappa=0 center dot 09), fair for SPE (kappa=0 center dot 25) and perfect for AGP (kappa=1 center dot 00). Sensitivity was high for AGP (100%) and low for AE (50%), SPE (37 center dot 5%) and histopathology (37 center dot 5%). Specificity was high for AGP or histopathology (100%) and low for SPE (50%) and AE (0%). Clinical Significance: IHC must always be performed to confirm FIP. If this is not possible, when histopathology is controversial, elevated AGP concentrations may support the diagnosis of FIP.