A comparison of three serological methods to detect chicken and turkey antibodies to avian nephritis virus and the use of virus‐specific monoclonal antibodies

Avian nephritis virus (ANV) strain G-4260 was inoculated orally in to 1-day-old and 3-week-old chickens and the sequential antibody response to the virus was monitored by serum neutralization, ELISA and immunofluorescence tests. The order of sensitivity of the serological tests was in the sequence given above, with the neutralization test being by far the most sensitive. There was no obvious difference in the antibody titres produced by either age group. Virus was recovered from kidney tissue, the highest titres being obtained 3 to 5 days post-inoculation. Histological examination revealed mainly lymphocytic infiltration of the interstitium and degenerative changes in the tubular epithelium of the kidney. The G-4260 strain of ANV was given orally to 1-day-old turkey poults, but no serological response was induced. Virus was not recovered from the kidneys and no histological lesions were produced in this organ. Monoclonal antibodies were produced which neutralized the infectivity of ANV. An antigen trap ELISA was developed using a monoclonal antibody and infected chicken kidney tissue cultures. However, this assay did not detect ANV in kidney samples taken directly from infected chickens, with the exception of one sample which was shown to contain the highest concentration of infectious virus.