Application of yeast enolase as antigen for immunodiagnosis of malaria.

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.

Neurone-specific enolase as a prognostic marker in childhood acute lymphoblastic leukemia

To test its diagnostic potential and sensitivity in pediatric malignancy, serum levels of neuron enolase [NSE] were measured by radioimunassay in thirty-one patients [18 male and 13 female] with acute lymphoblastic leukemia [ALL], and in thirty eight healthy children acting as controls with the same age match [1-12 years]. Of these patients, 96% had NSE levels more than three standard deviations> 10 micro g/L above the mean or normal children. Mean serum NES for acute lymphoblastic leukemia patients was 67.8 +/- SD 67.4 micro g/L [ranged 13-260 ug/L], whereas that in normal age-matched children was 4.5 +/- Sd 2.1 g/L [ranged 2.1-9.5 micro g/L]. Analysis of NES level in relation to the survival rate suggested that serum level greater than 100 ug/L were associated with poor outcome, and that serum NES levels may be a valuable tumor marker for screening and therapeutic monitoring of acute lymphoblastic leukemia in term of decreasing or intensifying the treatment to achieve remission