Twenty cats with FIP and twenty with FIV were studied. The objective of the present study was to establish the diagnostic value of these two tests in both diseases. Correlation between AGP and Albumin/Globulin ratio (A/G) and CD4/CD8 ratio were analyzed in both groups.

FIV was confirmed by serology and PCR (Polymerase Chain Reaction). FIP was confirmed by histopathology (vasculitis and perivasculitis). In addition to the evaluation of the clinical signs blood chemistry, hematology and other complementary diagnostic methods. CD4/CD8 by flow cytometry and AGP test were performed in order to establish the diagnostic value of these two tests in both diseases. CD4/CD8 ratio was performed with: 8100-01 Sowthern Biotechnology, anti CD4 Vpg 34, Willett, Glasgow University, anti CD8, VPG9, Willett, Glasgow University and Fluorescent antimouse IgG Southern Biotechnology, Becton and Dickinson Facs Scan Citometer. Feline α 1 glycoprotein (AGP) was performed with a radial immunodiffusion test provided by Ecos Institute, Japan. Pearson's Correlation between AGP and A/G and CD4/CD8 were analyzed in both groups. Parameters in each group were compared with non-paired samples T test with a significance of p<0,05. Results were expressed by mean +/- SD.

There was significant correlation between CD4/CD8 ratio and AGP in cats with FIP (r: -0,8293, p<0,0001) and in those with FIV (r: -0,56 p<0,01). AGP levels were higher than 1500 microgramos/ml in 80% of FIV patients and in 95% of FIP infected cats. CD4/CD8 ratio were compared in both group and significant differences (p< 0,007) were observed. These results can be adjudged to the FIV affinity for the CD4 depletion which was not detected in FIP patients. As to AGP and A/G there were not significant differences between group of cats. Consequently AGP can not distinguish FIP from FIV.

AGP determination in FIP patient could be a useful parameter to "confirm" the disease in alive cats in order to avoid the histopathological study.

On FIV infected cats CD4/CD8 ratio and AGP values could be good tools to determine stage and severity of the disease, because higher values of AGP are associated with low CD4 levels.