Urinary filarial antigen isolated from urine samples of microfilaraemi
c patients was analysed for its antigenic activity by immunoblotting a
nd enzyme linked immunosorbent assay.techniques. SDS-PAGE fractionatio
n of urinary filarial antigen showed 11 protein bands, of which two sh
owed reactivity with immunoglobulin-G fraction of filarial serum immun
oglobulin in immunoblotting. Antigenic analysis of SDS-PAGE fractions
of urinary filarial antigen by inhibition enzyme linked immunosorbent
assay using filarial serum immunoglobulin-G and Wuchereria bancrofti m
icrofilarial excretory-secretory antigen revealed 3 fractions, numbers
5, 6 and 9 with significant activity. In indirect enzyme linked immun
osorbent assay using fractions 5 and 6, filarial immunoglobulin-G anti
body was detected in about 90% of microfilaraemics, 80% clinical filar
iasis and 20% of endemic normal individuals. Further, there was no pho
sphorylcholine epitope in these fractions. Fractions 5 and 6 can be a
candidate antigens for the immunodiagnosis of filariasis.