IDENTIFICATION AND DISTRIBUTION OF SWINE SERUM IMMUNOGLOBINS THAT REACT WITH TRICHINELLA-SPIRALIS ANTIGENS AND MAY INTERFERE WITH THE ENZYME-LABELED ANTIBODY-TEST FOR TRICHINOSIS

Sera from T. spiralis digestion-negative swine contained variable amounts of 2 immunoglobulins (Ig) that reacted with T. spiralis antigen [Ag] in the indrect enzyme-labeled antibody [Ab] test for trichinosis. One of these Ig, detected by H chain-specific anti-swine IgG conjugate, was removed by absorption with T. spiralis larvae. A 2nd Ig, detected by H chain-specific anti-swine IgM, was not removed by absorption with T. spiralis larvae and increased in amount with the age of the animal. These 2 Ig varied independently in individual animals and showed some specificity for the Ag, i.e., they did not merely reflect changes in total serum IgG or IgM. In contrast to IgG anti-T. spiralis Ab from experimentally infected animals, neither of these Ig could be detected in double-diffusion tests against the Ag or by counter immunoelectrophoresis. Either of these Ig could interfere with the indirect test for T. spiralis Ab, depending upon whether anti-swine IgG or IgM conjugate is used. The factors which initiate synthesis and control serum concentrations of these Ig are not known.