Study of the circumoval precipitate in Schistosomiasis japonica by immunofluorescent technic

The 48-hour circumoval precipitates formed by infected human and rabbit sera on lyophilized Schistosoma japonicum eggs were stained with the corresponding fluorescein-labelled monospecific goat antisera for study under a fluorescent microscope. The three major Ig classes were found to participate in the formation of the precipitate, with major components being IgG and IgM; IgA participated least. IgE and C3 also contributed to the precipitate. The circumoval precipitate on S. japonicum eggs is therefore a complex of different immunoglobulins reactive with antigen(s) from the egg.