Antibody determination in the diagnosis of Wuchereria bancrofti infection in man.

The levels of IgG and IgE antibodies reacting with somatic antigens of adult Setaria digitata and Wuchereria bancrofti microfilariae were determined in sera of 90 patients with Bancroftian filariasis and 379 non-filarial subjects. Antibodies reacting with adult antigens and with soluble microfilarial antigens were seen in both microfilaraemic and amicrofilaraemic patients. Antibodies reacting with surface antigens of W. bancrofti microfilariae were seen only in amicrofilaraemic subjects. IgE antibodies were detected with the adult antigen only in both microfilaraemic and amicrofilaraemic patients. The absolute levels of IgG antibodies were significantly higher than those of IgE antibodies. It is concluded that the determination of serum antibodies reacting with adult antigens is suitable for the diagnosis of both the microfilaraemic and amicrofilaraemic phases of infection, and the determination of antibody to microfilarial surface antigens is applicable in patients with clinically evident disease.