Serum protein changes induced by plasmodium berghei infection in rats and plasmodium knowlesi infection in monkeys

Abstract
1. (1) A significant increase in the γ globulin fraction in the serum was observed in rats 6 to 7 months after infection with P. berghei. 2. (2) No significant changes in the protein fractions in the serum of rats were observed between the time of infection with P. berghei and the time of disappearance of the infection 25 to 84 days later or death of the animals as the result of infection. 3. (3) In animals “challenged” with P. berghei 6 to 7 months after initial infection, the γ globulin in the serum further increased after 19 weeks but by amounts which were not statistically significant. 4. (4) Serum protein fractions were observed at weekly intervals for 10 weeks in monkeys infected with P. knowlesi and the γ globulin was found to increase by amounts which were not statistically significant. 5. (5) Similar statistically insignificant differences were observed between the γ globulin fractions in the serum of uninfected monkeys and others which had been infected for 5 to 19 months with P. knowlesi. 6. (6) The statistically insignificant increases in γ globulin observed after malarial infection are probably not the result of chance, since they are constant in direction in the several similar experiments carried out.