Investigations of adenosine deaminase 1 (ADA-1), paraoxonase 1 (PON-1) ,c-reactive protein (CRP) and serum amyloid a (SAA) levels in cats infected with calicivirus

Feline calicivirus (FCV) commonly causes modarate or mild upper respiratory system infections in cats. On the other hand, it may also cause more sever and deatly systemic infections in cats. Infected cats with FCV be come carriers for a long period and these cats play an important role in the spread of the infection among the populated cats. FCV infections occurs in very high incidence in cats because of genetic and biotype variety, and also due to insufficient protective vaccines. Therefore, FCV infections are still important infections in cats. Most studies have been applied on the epidemiology of FCV infections upto date, but diagnosis and pathogenesis of FCV infections have not been well-decumanted. Thus, the aims of the presenet study were determination of cellular immune responses, oxidative stress, and inflammatory responses in cats infected with FCV. Furthermore, the diagnostic values of investigated-parameters in FCV infections were also evaluated. In the study, 20 cats infected with FCV and 10 clinically healthy cats were used. Oral swabs were collected from each cat and analysed with rapid FCV and feline herpesvirus (FHV) antigen test kits. Twenty cats positive to only FCV and 10 cats negative for both FCV and FHV were used as infected and control groups, respectively. Serum samples were collected from each cat and used to determine adenosine deaminase 1 (ADA-1), paraoxonase 1 (PON-1), C reactive protein (CRP) and serum amyloid A (SAA) by using cat-specific ELISA test kits. In the present study, serum concentrations of ADA-1, PON-1, SAA and CRP were significantly higher than those of Control Group (p< 0,001). Furthermore, high negative correlations were obtained between serum levels of ADA-1 and PON-1 (r=-0,73; p<0,001), while modarete correlations were obtained between other parameters in Pearson's Correlation analysis. Results of the present study showed that elevated serum ADA-1 levels indicate activated cellular immune responses and decreased PON-1 levels indicate oxidative stress. Furthermore, increased SAA and CRP levels determine the development of acute phase responses in cats infected with FCV. In conclusion, ADA-1 and PON-1 can be useful biomarkers for detecting activated cellular immune responses and oxidative stress in cats infected with FCV, respectively. Furthermore, SAA and CRP can be used to detect acute phase responses in infected cats with FCV.