Effect of Feline Immunodeficiency Virus Infection onToxoplasma gondii‐specific Humoral and Cell‐mediated Immune Responses of Cats with Serologic Evidence of Toxoplasmosis

Open Access
Publisher Website
Google Scholar
Abstract
Serum samples from 89 cats with serologic evidence of toxoplasmosis were identified by using an enzyme‐linked immunosorbent assay (ELISA) that detectedToxoplasma gondii‐specific immunoglobulin M (IgM) orT. gondii‐specific immunoglobulin G (IgG). Concurrent feline immunodeficiency virus (FIV) infection was detected in 36 cats using an ELISA for detection of FIV‐specific IgG. The majority of the cats in both the FIV‐seropositive and FIV‐seronegative groups were male and >5 years of age. FIV‐seropositive cats were more likely to haveT. gondiiIgM titers without IgG (P> 0.05) or anyT. gondiiIgM titer (P> 0.05) than were FIV‐seronegative cats. FIV‐seronegative cats (1328) had a higherT. gondiiIgG geometric mean titer than did FIV‐seropositive cats (724) and were more likely to haveT. gondiiIgG titers 1:2048 than were FIV‐seropositive cats (P> 0.05). Cats with serologic evidence of bothT. gondiiand FIV infections had persistentT. gondiiIgM titers for >12 weeks. Lymphoblast transformation in response to concanavalin A,T. gondii‐specific intracellular antigens, andT. gondii‐specific secretory antigens was compared inT. gondiiseropositive and FIV‐seronegative cats, cats with serologic evidence ofT. gondiiinfection alone, and cats with serologic evidence of concurrent FIV andT. gondiiinfections. Lymphocytes from all but one cat in the FIV‐seropositive group responded to concanavalin A. Whereas lymphocytes from FIV‐seronegative cats with serologic evidence of toxoplasmosis responded toT. gondii‐specific antigens, four of five of the FIV‐seropositive cats with concurrent serologic evidence of toxoplasmosis did not.