A BRUGIA-MALAYI ANTIGEN SPECIFICALLY RECOGNIZED BY INFECTED INDIVIDUALS

Western blot analyses were performed on 444 serum specimens: 40 sera f rom microfilaraemic individuals, 10 sera from elephantiasis patients, 24 treated individuals, 50 sera from residents of endemic areas withou t anti-filarial IgG4 antibodies (endemic normals), 20 sera from amicro filaraemic individuals with high antifilarial IgG4 antibodies, 200 ser a from healthy city-dwellers (non-endemic samples), and 100 sera from soil-transmitted helminth-infected individuals. Phast electrophoresis system was used to electrophorese Brugia malayi soluble adult worm ant igen on 10-15% SDS-PAGE gradient gels followed by electrophoretic tran sfer onto PVDF membranes. Membrane strips were then successively incub ated with blocking solution, human sera, and monoclonal anti-human IgG 4 antibody-HRP, with adequate washings done in between each incubation step. Luminol chemiluminescence detection was then used to develop th e blots. An antigenic band with the MW of similar to 37 kDa was found to be consistently present in the Western blots of all microfilaraemic sera, all amicrofilaraemic sera with high titres of anti-filarial IgG 4 antibodies, some treated patients, and some elephantiasis patients. The antigen did not occur in immunoblots of individuals with other hel minthic infections, normal endemic individuals, and city dwellers. The refore the B. malayi antigen of with the MW of similar to 37 kDa demon strated specific reactions with sera of B. malayi-infected individuals and thus may be useful for diagnostic application. (C) 1998 Academic Press.