Lymphoproliferative disease of turkeys: pathogenesis, viraemia and serum protein analysis following infection.

Turkey poults inoculated with plasma obtained from turkeys affected with lymphoproliferative disease (LPD) developed typical lymphoproliferative lesions in the pancreas, spleen and thymus, 3 and 6 weeks post infection. Virus-associated reverse transcriptase activity in plasma reached a significant level at 3 weeks and was further elevated at 6 weeks post infection, concomitantly with a marked increase in serum IgG, 7S-immuno-globulin level. There was no alteration in serum total iron binding capacity (transferrin) level in LPD virus-infected animals, as compared to controls. Natural field cases of LPD also demonstrated elevated serum IgG levels which persisted for more than 3 months, along with viraemia. There was a significant decrease in serum albumin concentration in about 30% of the infected animals, but in few of these turkeys was total serum protein elevated due to the very marked increase in gamma-globulins (IgG).