Progressive changes in serum proteins and the rheumatoid factor of chickens infected with Mycoplasma synoviae

Sera from controls and chickens infected with Mycoplasma synoviae were examined for serum protein content by cellulose-acetate electrophoresis, and for rheumatoid factor (RF) by a latex-agglutination test at 8, 18, 28, 38, and 48 days postinoculation (DPI). Mean total serum protein concentration was significantly elevated by 8 DPI and rose to much higher concentrations on each subsequent day of examination. The mean albumin concentration was significantly decreased by 8 DPI, and continued to decline to very low levels at 18 and 28 DPI, after which it began to rise and by 48 DPI did not significantly differ from the controls. The mean alpha-globulin concentrations were significantly elevated on all days of examination. The mean beta- and gamma-globulin concentrations were significantly elevated by 8 DPI and reached maximum levels at 18 DPI but remained elevated throughout the test. The percentage of chickens having RF titers increased on each successive examination day, but only 56% of the chickens had titers at 48 DPI.