Abstract
Objective—To determine whether FIV infection in captive African lions is associated with changes in immune cell variables similar to those detected in domestic cats infected with FIV.
Animals—5 captive African lions naturally infected with FIV (FIV+) and 5 lions not infected with FIV (FIV–).
Procedure—Peripheral blood samples were collected from FIV+ lions during annual examinations conducted during a 7-year period and at a single time point from the FIV– lions. From results of CBC and flow cytometry, lymphocyte subsets were characterized and compared.
Results—Flow cytometric analysis revealed that the percentage and absolute number of CD4+ and CD8+ T cells were significantly lower in FIV+ lions, compared with these values in FIV– lions. In FIV+ lions, severe depletion in the absolute number of CD4+ and CD8+ T cells was detected, although this did not correlate with clinical signs. Muscle wasting was the most consistent clinical sign of infection.
Conclusions and Clinical Relevance—Results suggest that FIV+ African lions develop lymphocyte deficiencies, including significant decreases in the absolute number of CD4+ and CD8+ T cells; these findings of immune dysfunction are similar to those defined for FIV+ domestic cats. It is important to monitor the number of CD4+ T cells in infected animals as a measure of disease progression. (Am J Vet Res 2003; 64:1293–1300)
