EFFECT OF CHEMOTHERAPY ON IMMUNE-RESPONSE TO EGG ANTIGENS OF SCHISTOSOMA-MANSONI IN CHRONICALLY INFECTED CHILDREN FROM AREAS OF LOW TRANSMISSION

In an attempt to identify antigenic molecules from Schistosoma mansoni eggs, a serological study was performed on children of a Venezuelan t own (Caraballeda) in which the transmission of schistosomiasis had bee n interrupted two years prior to sera sampling. Infected children rece ived treatment with Praziquantel and, based on the disappearance of eg gs in the stools plus negativization of the circumoval precipitin test (COPT) one year after treatment, they were classified as either respo nders or non-responders to chemotherapy. Western blots of soluble egg antigen (SEA) with a very sensitive chemiluminescent substrate were pe rformed. Sera from responder children recognized a 25 kDa band of SEA which diminished significantly after treatment. This was less frequent in non-responder children. When the sera of responder and non-respond er children were compared before treatment, we found that the recognit ion of the 40 and 41 kDa proteins could be predictive of response to c hemotherapy. All these antigens, used in ELISA-type techniques, might be of importance in the evaluation and follow-up of large scale schist osome control programmes.