Immunocytochemical localization of antigens recognized by asymptomatic microfilaremic patient's antisera in microfilariae of Wuchereria bancrofti

Ultrathin sections of microfilariae of Wuchereria bancrofti embedded in hyd rophilic resin were incubated with sera from patients, using antisera from asymptomatic microfilaremic patients with different microfilarial densities [1-100 microfilariae (mf)/ml, 101-500 mf/ml, > 1,000 mf/ml]. All groups st udied showed reactivity against relevant epitopes in all tissues of microfi lariae of W. bancrofti, instead of being localized in a specific nematode r egion, although the number of colloidal per square micron was inversely pro portional to the microfilaremia. Such results confirm data obtained by othe r authors and indicate a possible role for the humoral response in the mech anism for the destruction of circulating microfilariae.