ABSTRACT
In 1998, we reported that Plasmodium falciparum (Pf) enolase was useful as the capture antigen for the immunodiagnosis of malaria. In the present study, we modified a fluorescence-ELISA for the diagnosis of malaria by applying yeast enolase or rabbit muscle enolase as antigen. Sera from 67 falciparum malaria patients and 15 vivax malaria patients were tested by the method. Positivity rates of the former was 82.1% against yeast enolase antigen and 90.5% against rabbit muscle enolase antigen, and those of latter was 93.3% against both enolase antigens. Mean antibody level (RFU values) of sera from falciparum and vivax malaria patients were significantly higher than those from healthy individuals. There was a significant correlation between anti-yeast and anti-rabbit muscle enolase antibody level (RFU values) in the group of falciparum subjects (r = 0.401, p<0.001). A significant correlation between RFU values against yeast enolase antigen and indirect fluorescent antibody titers against crude Pf antigen in the same subjects was recognized (r = 0.518, p<0.001). Longitudinal changes of RFU values against yeast enolase for the following 4 weeks after admission were also examined for sera from falciparum malaria patients. Patients with more severe malaria showed increasing RFU values as the clinical courses progressed. However, in the mild cases, each RFU value stayed unchanged during the course. We concluded that yeast and rabbit muscle enolase could be appropriately used as antigen for the immunodiagnosis of malaria.
Subject(s)
Animals , Antibodies, Protozoan/blood , Case-Control Studies , Enzyme-Linked Immunosorbent Assay , Humans , Malaria, Falciparum/blood , Malaria, Vivax/blood , Phosphopyruvate Hydratase/diagnosis , Rabbits , Severity of Illness Index , Thailand , YeastsABSTRACT
It was reported that a 47kDa antigenic polypeptide of Plasmodium falciparum had been strongly presented by the sera from 1) imported Japanese malaria patients with severe symptoms and 2) symptomatic and parasitemic inhabitants in endemic areas in the Sudan, Malaysia and the Philippines. In the present study, we observed the reactivity of the sera from falciparum malaria patients who had been hospitalized in the Bangkok Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, and compared the antibody response against the 47kDa antigenic polypeptide according to the severity of the patients. It was observed that antibodies to this molecule were more commonly shared in sera from severer patients, although the IFAT titers against the whole P. falciparum parasite antigen were lower in the group, which suggested that this antibody against the 47kDa molecule was playing a specific role at a severe stage of the infection. Determination of the immunological features of the antigenic molecules of parasites by this type of sero-epidemiological study will provide a new assay system for evaluation of immune status of individuals in different severity and suggest a way of vaccine development.
Subject(s)
Adolescent , Adult , Aged , Animals , Antibodies, Protozoan/biosynthesis , Antigens, Protozoan/immunology , Blotting, Western , Electrophoresis, Polyacrylamide Gel , Female , Fluorescent Antibody Technique, Indirect , Humans , Malaria, Falciparum/blood , Male , Middle Aged , Plasmodium falciparum/immunology , Severity of Illness Index , ThailandABSTRACT
A case of Dipetalonema perstans infection in a 34-year-old Japanese male is presented and from his past history there is no doubt that he obtained the infection in Zaire, Africa. The morphology and periodicity of the microfilaria were studied in detail and the clinical manifestations of the infection documented. This is the first report of imported D. perstans infection in Japan.