Antibody response in patients infected with one common strain of Campylobacter jejuni. Evidence for production of antibodies against thermostable soluble antigens.

Antibody production was investigated for ten patients from a group of 20 who had contracted infections with a strain of Campylobacter jejuni of serotype PEN 6,7. Production of antibody was determined by titrating ten sets of paired sera for agglutination of formalin-treated and heat-treated cell suspensions and by passive hemagglutination using both sheep and human O Rh-red blood cells sensitized with extracted soluble thermostable antigens. All patients had demonstrable antibodies against the formalin-treated cells, six had a four-fold or greater increase in antibody levels. Nine patients showed antibodies against the heat-inactivated cells of whom five showed a fourfold or greater rise in antibody levels. Three patients developed antibodies against the extracted thermostable antigens. Sera from 100 blood donors served as controls. Six paired sera from patients that had antibodies against the heated suspension were analyzed by an immunofluorescence technique for determining IgM, IgA and IgG antibodies against live and heat-inactivated bacteria. Each of the six sera displayed antibody response primarily of the IgM and IgA class with highest levels against live cell suspensions.