[Establishment and application of dipstick sandwich colloidal dye immunoassay for circulating antigen detection in schistosomiasis patients].
OBJECTIVE
To set up a simple immunoassay for the detection of circulating antigens in host serum.


METHODS
A kind of colloidal pale purple dye (HFRL) used as a staining reagent for immunoassay was first selected from the dyes produced in China and an optimum condition for labelling the dye onto the combined IgM antibodies was explored. A dipstick sandwich colloidal dye immunoassay (DS-DIA) for the detection of circulating antigens in host sera was established.


RESULTS
The minimal concentration of SEA detected was 5 ng/ml by DS-DIA. Serum circulating antigen detection in 14 cases of acute schistosomiasis japonica, 113 chronic cases and in 113 healthy controls revealed that the sensitivity was 100% in acute cases, 52.2% in chronic cases and the specificity was 92.9% for uninfected students. The sensitivity and specificity of DIA were similar to those of dot-ELISA. A certain degree of diagnostic complementarity up to 76.1% in sera from these patients was seen when DS-DIA and dot-ELISA were used in paralle.


CONCLUSIONS
DS-DIA is a simple, economical and reliable method for detecting circulating antigens of Schistosoma japonicum, having a wide potential value especially for field use.
Xie
Y
Y
Department of Parasitology, Shanghai Second Medical University, Shanghai 200025.
Xue
C
C
Lou
W
W
D000328:Adult; D000818:Animals; D000947:Antigens, Helminth / Q000097:blood*; D004396:Coloring Agents; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D012549:Schistosoma japonicum / Q000276:immunology*; D012554:Schistosomiasis japonica / Q000175:diagnosis*; D012680:Sensitivity and Specificity
D000947:Antigens, Helminth; D004396:Coloring Agents