Evaluation of in-vitro-cultured Plasmodium falciparum as antigen for malaria serology.
A handicap in developing seroepidemiology for malaria in India is the lack of homologous antigens. Aotus monkeys, in which human plasmodia can be propagated, are not easily available in India. Other alternatives include the use of infected human blood or the in-vitro culture of Plasmodium falciparum, using the candle-jar technique of Trager & Jensen (1976). With certain modifications, the in-vitro culture technique has been established at the St John's Medical College (SJMC) to obtain a regular and high yield of P. falciparum to use as a source of antigen in serological tests. Antigens prepared from in-vitro-cultivated P. falciparum have been tested against positive and negative reference sera by the indirect haemagglutination (IHA) and immunofluorescent antibody (IFA) tests. These reference sera were also tested with the IHA test by using P. falciparum-sensitized human "O' erythrocytes received from the Center for Disease Control (CDC), Atlanta. IHA test results with both types of antigens were comparable (Spearman rank correlation coefficient, rS=0.8440, P less than 0.01). The antigen from in-vitro culture was also found suitable for use in the IFA test. The IFA titres obtained were comparable to those found at the CDC (Spearman rank correlation coefficient, rS=0.7940, P less than 0.01). These results indicate that P. falciparum parasites prepared from in-vitro continuous culture can be used as a source of antigen for use in the IHA and IFA tests for malaria.
D000941:Antigens; D005455:Fluorescent Antibody Technique; D006386:Hemagglutination Tests; D006801:Humans; D008288:Malaria / Q000175:diagnosis*; D010963:Plasmodium falciparum / Q000276:immunology*
D000941:Antigens