HUMORAL IMMUNE-RESPONSE OF CHILDREN WITH CHRONIC SCHISTOSOMIASIS - ISOTYPE RECOGNITION OF ADULT WORM ANTIGENS

In areas of low transmission of schistosomiasis, the evaluation of the success of control depends on reliable diagnostic tests. Under such c onditions, some of the serological tests better estimate the real prev alence of this parasitosis than the classical stool examinations. On t he search of higher sensitive and specific antigenic fractions for use in serological tests, an immunoblot technique with a luminescent subs trate teas used in order to evaluate, under dissociating and reducing conditions, the Schistosoma mansoni adult worm antigen (AWA). The sera of 30 infected Venezuelan children were assayed for specific recognit ion of AWA by IgG, IgM, IgE, IgA, and the foul IgG subclasses. Eight h ighly specific polypeptide molecules fr om the parasite of 118, 114, 1 05, 74, 71, 45, 36, and 30 kDa were recognized by total IgG. Additiona lly, IgG1 and IgG2 recognized a molecule of 100 kDa and IgM one of 77 kDa. The present data suggests that certain molecules from the adult w orm, specially the 36 kDa, might be relevant in the specific immunodia gnosis of this parasitic disease. The fact that the children antibodie s were able to recognize the primary structure of these antigens, will allow us to chemically synthesize the relevant linear epitopes.