Schistosomiasis is a chronic debilitating disease affecting 200 -300 million
throughout the world, a major focus of research has been done to identify and
characterize antigens that may have vaccine and/or diagnostic potential. In the
present study, NP-40 extracted surface proteins of Schistosoma mansoni (S.
mansoni) adult worms were subjected to 12.5% Sodium Dodecyl Sulfate–
Polyacrylamide Gel Electrophoresis (SDS-PAGE) and electrotransfered onto a
nitrocellulose membrane (PVDF), then, incubated with pooled sera collected from S.
mansoni chronically infected patients. The presence of antibodies identify a number
of NP-40 extracted surface proteins of the adult worms of S. mansoni. One of these
proteins of 38 kDa molecular weight with high immunogenicity was selected. The
strip of nitrocellulose membrane containing the complex of the identified protein and
its specific antibody was cut guided by the molecular weight marker, then, the
antibody was micro-eluted. Proteins of urine samples from the same patients were
precipitated and purified over G-Sephadex column. The purified proteins of urine
samples and proteins of sera were subjected to another SDS- PAGE and electrotransferred
onto PVDF membrane. The microeluted antibody was used to identify an
antigen of 38 kDa molecular weight in sera of the chronically infected patients as
well as in urine. The 38 kDa antigen was excreted in the urine of those patients in a
stable form and detected by the specific monoclonal antibody. The active epitope of
38 kDa antigen could be a promising immunochemical probe for S. mansoni
infection diagnosis. Further studies will be done to characterize that antigen as well
as its potential application in immunodiagnosis for S. mansoni