Effect of immunosuppression on pathogenesis of peste des petits ruminants (PPR) virus infection in goats.

In this study an attempt to address the effects of immunosuppression on pathogenesis of peste des petits ruminants (PPR) virus infection was undertaken. Cyclophosphamide and dexamethasone were used to immunosuppress the animals. The drug treated animals exhibited severe leukopaenia and lymphopaenia; one of the indicators of immunosuppression. Experimental peste des petits ruminants virus (PPRV) infection was then given to both drug-induced immunosuppressed and non-immunosuppressed goats and observed their effects. Findings indicated that, the immunosuppressed goats had a short period of viremia, more extensive and severe disease advancement and higher mortality rate than the non-immunosuppressed goats. PPRV antigen distribution in both ante-mortem and post-mortem materials was extensive and diffused in immunosuppressed animals than that of non-immunosuppressed. Some of the atypical organ(s)/tissues like liver, kidney, heart etc showed more antigen load than non-immunosuppressed group. Histopathological and immunohistochemical studies of tissues from the two groups showed that pathological changes in the non-immunosuppressed animals were confined only to gastrointestinal tract, whereas in the immunosuppressed animals histopathological changes and PPRV antigen distribution were more extensive and diffused. The present study indicated that immunosuppression increased the extent and severity of the pathological lesions associated with peste des petits ruminants virus infection.