THE MEASUREMENT OF ANTIBODY IN HUMAN MALARIA BY A FORMOLIZED TANNED SHEEP CELL HAEMAGGLUTINATION TEST.

A major obstacle to serological testing for malaria immunity has been the difficulty in obtaining sufficient antigen from the small, intracellular parasite. This is overcome by the formolized, tanned, sheep red cell haemagglutination test described in this paper, as only minute quantities of antigen protein and very small amounts of patient's serum are required for its performance.In the trials reported, antigens derived from Plasmodium berghei, P. vivax, P. coatneyi and P. cynomolgi were tested mainly against sera from patients with P. vivax infections. Sera from these patients gave highest titres (up to 1:25 600) with P. cynomolgi and P. vivax antigens. Positive haemagglutination reactions were noted with P. berghei antigens but in lower titres. P. coatneyi antigens cross-reacted with the few sera from patients with P. falciparum infections that could be tested.The authors foresee the application of this test for following the immune reaction during the course of malaria infections and for determining the antigenic relationship between different Plasmodium species.