Prevalence of autoantibodies that bind to kidney tissues in cats and association risk with antibodies to feline viral rhinotracheitis, calicivirus, and panleukopenia.

Background: The feline viral rhinotracheitis, calicivirus, and panleukopenia (FVRCP) vaccine, prepared from viruses grown in the Crandell-Rees feline kidney cell line, can induce antibodies to cross-react with feline kidney tissues.

Objectives: This study surveyed the prevalence of autoantibodies to feline kidney tissues and their association with the frequency of FVRCP vaccination.

Methods: Serum samples and kidneys were collected from 156 live and 26 cadaveric cats. Antibodies that bind to kidney tissues and antibodies to the FVRCP antigen were determined by enzyme-linked immunosorbent assay (ELISA), and kidney-bound antibody patterns were investigated by examining immunofluorescence. Proteins recognized by antibodies were identified by Western blot analysis.

Results: The prevalences of autoantibodies that bind to kidney tissues in cats were 41% and 13% by ELISA and immunofluorescence, respectively. Kidney-bound antibodies were observed at interstitial cells, apical border, and cytoplasm of proximal and distal tubules; the antibodies were bound to proteins with molecular weights of 40, 47, 38, and 20 kDa. There was no direct link between vaccination and anti-kidney antibodies, but positive antibodies to kidney tissues were significantly associated with the anti-FVRCP antibody. The odds ratio or association in finding the autoantibody in cats with the antibody to FVRCP was 2.8 times higher than that in cats without the antibody to FVRCP.

Conclusions: These preliminary results demonstrate an association between anti-FVRCP and anti-cat kidney tissues. However, an increase in the risk of inducing kidney-bound antibodies by repeat vaccinations could not be shown directly. It will be interesting to expand the sample size and follow-up on whether these autoantibodies can lead to kidney function impairment.