Masamitsu Otsuru

Detection of antibodies in strongyloidiasis by enzyme-linked immunosorbent assay (ELISA)

Detection of IgG antibodies to Strongyloides stercoralis in sera of 29 patients with strongyloidiasis was attempted by the enzyme-linked immunosorbent assay (ELISA) using an extract of filariform larvae of S. stercoralis. The antibodies were found with a high degree of sensitivity in almost all patients. The ELISA values, however, did not correlate with the intensity of the infection or with differences in clinical and laboratory parameters. When the ELISA values of persons with Strongyloides were compared with those showing no S. stercoralis by faecal examinations, a significant difference was obtained between these two groups. The cross reactions with other helminth infections were significantly weaker than the reaction with Strongyloides infection. It was concluded that the antibodies are strongly elicited in human strongyloidiasis and that the assay provides a sensitive and specific method for diagnosis of strongyloidiasis.

Polyclonal B cell activation during the course of Angiostrongylus cantonensis infection

The numbers of IgM antibody forming cells against various heterologous antigens: SRBC, HRBC, TNP and FITC, were found to be elevated in the spleens of rats after infection with Angiostrongylus cantonensis. In these rats, the number of splenic B cells and total IgG and IgM levels in serum also increased spontaneously about 2- to 3-fold of uninfected rats during the course of the infection. These results suggested that A. cantonensis infection may activate B cells polyclonally in the spleens of the infected rats. While, it was clearly observed that the antibody response to SRBC injection was significantly depressed in these rats, compared to those of uninfected rats. The relation between the polyclonal B cell activation and the immunodepression was discussed.