RAPID COMPETITIVE ENZYME-LINKED-IMMUNOSORBENT-ASSAY USING A MONOCLONAL-ANTIBODY REACTING WITH A 15-KILODALTON TEGUMENTAL ANTIGEN OF SCHISTOSOMA-MANSONI FOR SERODIAGNOSIS OF SCHISTOSOMIASIS

A competitive enzyme-linked immunosorbent assay (CELISA) for antibody detection was developed by using a monoclonal antibody which reacts wi th a 15-kDa tegumental antigen of the adult worm of Schistosoma manson i. This monoclonal antibody was not able to react with antigens of Sch istosoma japonicum or Schistosoma haematobium in enzyme-linked immunoe lectrotransfer blot (EITB) and indirect immunofluorescence tests. The assay was performed in a period of 1 h using an adult worm crude extra ct antigen. To evaluate the CELISA, a total of 73 serum samples was an alyzed: 35 were from S. mansoni-infected patients, 23 were from indivi duals with parasitic infections other than schistosomiasis, and 14 wer e from healthy individuals. All serum samples from healthy individuals and from patients infected with other parasites were negative, as wer e two (6%) samples from patients infected with S. mansoni. EITB analys is showed that 32 of 33 CELISA-positive samples were positive in the E ITB but with different patterns of reactivity. A 15-kDa protein reacte d with 60% of serum samples, and a 60-kDa protein showed the highest l evel of reactivity (85%). The two samples from patients infected with S. mansoni that were negative in the CELISA reacted with 70-, 60-, 50- , 47-, and 38-kDa proteins. One sample, positive in CELISA, did not re act with proteins of the antigenic extract.