Experimental infection with Plasmodium chabaudi in rats: antigen and antibody associated with anemia and glomerulonephritis of acute infection.

Rat-adapted Plasmodium chabaudi caused a syndrome characterized by hemolytic anemia, splenomegaly, and glomerulonephritis. All rats recovered and appeared normal after 4 weeks despite persistence of proteinuria. Serologic studies on the malarious rats revealed that the infection was associated with a soluble antigen which was present concurrently with antibody in plasma, in material eluted from blood cells, in extracts of kidney tissues, and in the urine. This antigen appeared to be identical with one extracted from P. chabaudi parasites and did not cross-react with antigens of Plasmodium gallinaceum. Tests for the cold-active hemagglutin (CAH) and the globulin associated serum antigen (SA) previously associated with acute malaria, revealed that CAH, but not SA, was present. From these observations it is suggested that soluble complexes of the parasite antigen and its antibody may have been causal in this syndrome.