Expression of viral arthritis-tenosynovitis infection in immunosuppressed chickens

Previously untreated chicks and those treated neonatally with either cyclophosphamide (CY) or infectious bursal disease virus (IBDV) were subcutaneously inoculated with viral arthritis virus ( VAV ) to determine whether suppression of humoral immunity would affect VAV pathogenicity. No difference was apparent in the disease process that occurred in the immunosuppressed versus the nonimmunosuppressed chickens. However, in the immunosuppressed birds, VAV was recovered from the heart and tendon tissues earlier in the postinoculation (PI) period. Also, VAV inoculated immunosuppressed birds carried higher levels of serum gamma globulins at certain PI intervals than the VAV inoculated positive controls or the untreated negative control chickens. It is suggested that the suppression of the bursa of Fabricius (BF) by CY or IBDV did not interfere in the antibody production to VAV , but the antibody produced was qualitatively defective.