A LONGITUDINAL-STUDY OF LYMPHOCYTE SUBSETS IN A COHORT OF CATS NATURALLY-INFECTED WITH FELINE IMMUNODEFICIENCY VIRUS

Despite the potential of feline immunodeficiency virus (FIV) as an ani mal model for human immunodeficiency virus (HIV) studies, the long ter m effects of naturally-occurring infection have not been determined, H IV infection causes an ongoing deterioration in immune function which directly correlates with disease, in particular acquired immunodefcien cy syndrome (AIDS), However, it is not known whether FIV-induced immun osuppression is progressive or related to the clinical condition, This study examined changes in lymphocyte subset numbers of serial samples , taken from cohorts of FIV-positive and FIV-negative cats over an 18- month period, FIV-positive cats were clinically staged as asymptomatic carriers (AC) or eats with AIDS-related complex (ARC), and FIV-negati ve cats matched and staged on the basis of similar diseases, During th e course of the study, 4 FIV-positive cats developed AIDS, classed as the terminal stage of infection, There were no significant differences in the mean absolute numbers of any lymphocyte subset between the ons et (t(0)) and the completion (t(18)) of the study. Similarly there wer e no significant changes in subset numbers during the 18 months preced ing the development of AIDS. While the study period was brief and the sample sizes small, it is postulated that FIV infection in Australia m ay not necessarily cause progressive immunodeficiency and that FIV-ind uced immunosuppression (as measured by subset analysis) may not be wel l correlated with the clinical status of the infected cat.