Heterozygosity at the Km locus associated with humoral immunity to Campylobacter jejuni.

Serum samples from 43 Caucasian subjects convalescing from acute Campylobacter jejuni infection were typed for nine Gm and two Km determinants. The sera were also used to measure IgA, IgG, and IgM classes of antibody to acid-labile surface proteins of C. jejuni by an enzyme-linked immunosorbent assay. A highly significant association (p = 0.004) was found between Km1/Km3 heterozygotes and the level of IgA antibodies. These results suggest the existence of complementary immune response genes which in the heterozygous condition permit a humoral response to C. jejuni.