Studies on hemagglutination test on filariasis. I. The fractionation and purification of antigens by column chromatography and disc electrophoresis.

The fractionation of antigens for hemagglutination test from adult worms of Dirofilaria (D.) immitis was carried out by defatting with diethylether, sonication, centrifugation, gel-filtration on sephadex G-100 column, DEAE cellulose column chromatography, saturation with ammonium sulfate and disc electrophoresis. An antigen FPSD4 thus obtained, showed potent HA activity against sera from patients infected with Wuchereria (W.) bancrofti. But it was also reactive with normal sera. After elimination of the cross-reacting substance from antigen FPSD4 by the saturation of ammonium sulfate, a specific antigen FPSD4-2 was obtained. By the tests using FSCD4-2 in a protein concentration of 20 mug/ml, sera of 27 patients with microfilariae of W. bancrofti in their blood were examined and 18 positive cases (66.7% positive) were obtained. With 21 normal human sera, no cross reaction was found. As antigen FPSD4-2 showed about 20 protein bands, the further purification of the antigen by disc electrophoresis was carried out. Among three subfractions thus obtained, FPSDA which contained 5 protein bands was most reactive and specific.