EVALUATION OF ANTIBODIES REACTIVE WITH CAMPYLOBACTER-JEJUNI IN EGYPTIAN DIARRHEA PATIENTS

Serum and stool samples were collected from 128 individuals: 96 diarrh ea patients and 32 apparently healthy controls. Stool specimens were c ultured for enteric bacterial pathogens, while sera were screened by e nzyme-linked immunosorbent assay for Campylobacter jejuni-reactive ant ibodies. Of 28 diarrhea patients who demonstrated C. jejuni-reactive a ntibodies (titers, > 100), 14 were culture positive for this organism. The 32 healthy controls showed significantly lower antibody titers (P < 0.05) with the exception of 10 subjects who were culture positive f or C. jejuni and had reactive immunoglobulin M (IgM) (6 subjects) and IgG (7 subjects). IgA was not detected in those 10 individuals (asympt omatic). Avidity was expressed as the thiocyanate ion concentration re quired to inhibit 50% of the bound antibodies, The avidity was higher in symptomatic patients than asymptomatic healthy controls. IgG was le ss avid (0.92 M) compared to IgM (0.1 M) and IgA (1.1 M), with no corr elation between antibody titer and avidity, However, the thiocyanate i on concentration required for the complete inhibition of IgG (5 M)-bou nd antibodies was higher than that of IgA (2 M) and IgM (3 M), This st udy also shows that C. jejuni antibodies were variably cross-reactive with Escherichia coli, Shigella flexneri, Shigella sonnei, and Neisser ia meningitidis in addition to Campylobacter coli and Campylobacter re ctus.