Immunoglobulin G response in patients with Campylobacter concisus diarrhea.

Limited information is available on the systemic immunoglobulin response in patients infected with the emerging pathogen Campylobacter concisus. The aim of the present study was to detect anti-C. concisus antibodies in serum of 88 patients with C. concisus gastroenteritis. Specific IgG antibodies to C. concisus were measured in serum using an in-house enzyme-linked immunosorbent assay, and pooled donor serum was used as a control. The mean optical density was 0.135 (SEM: 0.020) for the 88 adult patients and 0.100 (SEM: 0.011) in controls. When using an optical density value equal to the mean +3 SEM for the control serum, 22 (25%) C. concisus-positive patients had increased IgG antibodies. Patients with high IgG levels more often reported headache, and they had a trend toward more mucus in stools, whereas IgG levels were unrelated to age, duration of diarrhea, number of stools per day, and weight loss.