Detection of FeLV antigen by indirect immunofluorescence in ELISA/CITE negative cats

摘要

THE difficulties arising from false positive results on standard ELISA/CITE feline leukaemia virus (FeLV) tests have been discussed by a number of authors (Jarrett and others 1982, Jacobson and Lopez 1991), and it is routinely recommended in the USA that all FeLV ELISA-positive cats have such results confirmed by immunofluorescent antibody (IFA) testing (Scott and others 1991). However, the opposite problem, cats which clinically and haema-tologically show every indication of suffering from FeLV while ELISA/CITE tests give negative results, seems to be the greater concern in general practice in the UK (Gruffydd-Jones 1992). In this context it is noteworthy that false negative ELISA results have also been reported from the USA (Hardy and Zuckerman 1991b). The indirect IFA test as described by Hardy and others (1973), Weijer and Daams (1976) and Hoover and others (1978) has been in general use in Europe and the USA for many years. It is more sensitive and specific than the ELISA and it is generally considered to be the reference method (Hardy and Zuckerman 1991a, b), however, it has to date not been adopted for general diagnostic use in the UK. This report describes the use of the IFA FeLV method in the investigation of cats referred from veterinarypractices in this country, with particular reference to the identification of FeLV involvement in cats presenting with signs suggestive of FeLV-associated disease but which were negative on ELISA.