COMPARISON OF ANTIBODY ISOTYPE RESPONSES TO SCHISTOSOMA-MANSONI ANTIGENS BY INFECTED AND PUTATIVE RESISTANT INDIVIDUALS LIVING IN AN ENDEMIC AREA

The isotopic patterns of antibodies against Schistosoma mansoni antige nic preparations from eggs (SEA), adult worms (SWAP) and cercariae (CE RC) have been studied in sera from two groups of individuals living in an area endemic for S. mansoni. One of the groups was comprised of in dividuals diagnosed as having S. mansoni infections based on their pat ency, i.e. those passing eggs in their faeces (patent infections, PI). The other group has been consider putatively resistant' due to their residence in an endemic area, their documented exposure to positive tr ansmission sites, and their repented negativity upon stool examination s (endemic normals, EN). There are strong specific responses of IgG1, IgG4 and IgM, particularly to SEA and CERC, by both groups. The reacti vities of all isotypes were lower to SWAP. The responses of IgG4, IgM anti IgE anti-CERC in EN and PI are higher than those found in normal individuals from outside endemic areas. In general, EN individuals exp ress a relative higher level of anti-STEG IgE as compared to IgG4, On the other hand the pool of ser a from PI showed the opposite pattern o f higher IgG4 as compared to IgE. Several correlations are seen betwee n isotypic responses to SEA, SWAP and CERC based on comparisons to the anti-SWAP IgE responses of the individuals in the two groups. These c omparisons indicate the presence of distinct immunologic differences b etween individuals in the PI and the EN groups.