A 33-35 kDa circulating antigen from Plasmodium falciparum

Abstract

Isolation and characterisation of Plasmodium falciparum (Welch, 1897) soluble antigens from infected patient plasma, Western blotting, thermal stability and ELISA assays using hyperimmune IgG-antimalaria antibodies was the main objective of this work. A circulating antigen of approximately Mr 33-35 kDa with good specificity and antigenicity, in the plasma of malarial patients was shown. Heating at 100°C did not destroy its antigenicity. When fractions highly enriched in the 33-35 kDa proteins were used in ELISAs, a seroreactivity in plasma obtained from primary-infected individuals was found. Controls from normal patients were always negative. The antigenic characteristics suggest that it may be included within the group of new described Plasmodium soluble antigens.