Serum immunoglobulin and antibody levels and the passive transfer of resistance in hamsters infected with Dipetalonema viteae.

Clearance of microfilariae from the circulation of hamsters infected with Dipetalonema viteae was demonstrated following passive transfer of serum obtained from hyperinfected hamsters. The exclusion fraction after gel filtration of this serum on Sephacryl S 200 also cleared microfilariae whereas the other fractions did not. There was no clearance with serum taken during the pre-patent, patent or latent periods of singly infected hamsters. IgM antibody to the microfilaria cuticle measured by the fluorescent antibody technique was increased 2 to 4 times in the protective serum over the other sera. Suppression of microfilaremia was also adoptively transferred by cells from infected hamsters. Serum Ig and antibody levels to microfilaria cuticle were measured in 3 strains of hamsters differing in their ability to clear microfilariae. IgM antibody to microfilaria cuticle correlated with the ability to clear. No IgG antibody to microfilaria cuticle was detected and the major Ig response to infection was in IgG1, which increased 10 to 20 fold.