Danielle Golds, Sarah Tayler

The Royal Veterinary College, Queen Mother Hospital for Animals, Hatfield, United Kingdom

Objectives

To evaluate haematological and biochemical inflammatory markers alongside the systemic immune-inflammation index (SII) as prognostic indicators in cats diagnosed with feline infectious peritonitis (FIP) receiving antiviral therapy.

Methods

This was a single-centre, retrospective study. Medical results of 177 cats diagnosed with FIP were reviewed, with 105 cats meeting the inclusion criteria. Data collected included packed cell volume, neutrophil and lymphocyte absolute counts, manual platelet estimation, albumin, globulin, and serum amyloid A (SAA). Albumin to globulin (A:G) ratio, neutrophil to lymphocyte (N:L) ratio, and SII [(platelet count x neutrophil count) / lymphocyte count] were subsequently calculated. Further data collected included initial antiviral drug doses administered, survival to discharge, and survival at 12 weeks post-initiation of antiviral treatment.

Results

Independent t-test and Mann-Whitney U tests identified lower A:G ratio (p = 0.029), lower lymphocyte count (p < 0.001), lower manual platelet estimation (p < 0.001) and a higher N:L ratio (p = 0.002) were significantly associated with non-survival to discharge. Binary logistic regression analysis revealed SII (OR 1.000; 95% CI 1.000-1.000; p = 0.502), SAA (OR 1.016, 95% CI: 0.992–1.041, p = 0.195), and antiviral dose (OR = 0.929, 95% CI 0.780–1.107, p = 0.411) were not significantly associated with survival to discharge. Receiver operating characteristic curve analysis demonstrated poor predictive performance of SII.

Statement: Impact/ Clinical Significance

SII was limited as a predictor of outcome in cats diagnosed with FIP. Individual analysis of N:L ratio, A:G ratio, lymphocyte count, and platelet count may be more relevant to assess associations with survival outcomes.