Some Serum Globulin Changes in East Coast Fever

Abstract

Using single radial immunodiffusion tests, changes in concentrations of IgG 1 , IgG 2 , IgM and a protein designated 7Sγ 1 were measured in the sera of cattle undergoing mild, severe and fatal reactions to experimental East Coast fever (Theileria parva infection). In cattle dying of East Coast fever there was a profound fall in IgM and 7 S γ 1 levels after establishment of T. parva in the peripheral lymph nodes; IgG 1 levels also fell, but not IgG 2 . In cattle that recovered from severe infections there was a marked drop in the levels of all 3 immunoglobulins and in 7 Sγ 1 , but not until the peak of the clinical reactions. In these cattle the levels ofIgG 1 , IgG 2 and IgM returned to the pre-infection levels within 5 days and of 7 Sγ 1 within 14 days. However, the IgG 1 and, in particular, IgM levels continued to rise after recovery from infection, reaching a peak concentration by day 28 post-infection and thereafter falling slowly to pre-injection levels. In cattle recovering from mild infections there were negligible effects on IgG 1 and IgG 2 levels, but a rise in IgM and a slight fall in 7 Sγ 1 levels were detected.