The Mongolian jird is used widely in
filariasis research for studies of protective immunity, pathogenesis, and
therapy. The purpose of this study was to evaluate parasite
antigen detection as a means of noninvasively monitoring Brugia pahangi
infection in jirds. A parasite
antigen with Mr of 105-110 kDa was identified in sera from i.p.- and s.c.-infected jirds by immunoblot with a
monoclonal antibody to
phosphorylcholine. The same antibody was used in a direct sandwich
enzyme immunoassay to measure
antigen in jird sera. Parasite
antigen was detectable as early
as 2 wk after i.p. or s.c. injection of L3.
Antigen titers increased between 2 and 12 wk and stabilized between 12 and 36 wk after
infection in s.c.-infected animals. A different pattern was seen in i.p.-infected jirds with
antigen titers peaking at 16 wk and falling significantly between 16 and 32 wk after
infection. Parasite
antigen titers correlated significantly with adult worm
infection intensities in jirds with mature i.p. and s.c.
infections. Antigenemia was also detectable in sera from jirds after i.p. implantation of adult parasites of either sex. However,
antigen was not detected in sera from infant offspring of antigenemic infected mothers. We conclude that parasite
antigen detection allows B. pahangi development and survival as well as
infection intensity to be monitored in living animals with unprecedented sensitivity and accuracy. This technique should facilitate
drug and
vaccine studies in this important experimental
filariasis model.