Stool PCR for Gastrointestinal Pathogens in Patients With and Without Immune-Mediated Intestinal Diseases

Background: Patients with celiac disease and inflammatory bowel disease, two immune-mediated luminal conditions, have higher rates of certain infections than healthy counterparts. The prevalence of many gastrointestinal infections in these patients, however, is unknown.

Aims: Using a novel clinical stool pathogen PCR test, we investigated the hypothesis that patients with celiac disease/inflammatory bowel disease had different distributions of diarrheal pathogens than other patients.

Methods: We performed a retrospective cohort study of outpatients who underwent stool pathogen testing with the FilmArray Gastrointestinal PCR Panel (BioFire Diagnostics, Salt Lake City, UT) at our institution from January 1 to December 31, 2015. Rates of pathogens were measured in patients with or without celiac disease/inflammatory bowel disease.

Results: Of 955 patients, 337 had positive test for any pathogen, with 465 bacterial, parasitic, or viral pathogens identified. One hundred and twenty-seven patients (13.3%) had celiac disease or inflammatory bowel disease, of which 29/127 (22.8%) had a positive test, compared to 308/828 other patients (37.2%) (p = 0.002). Patients with celiac disease/inflammatory bowel disease had significantly fewer viruses (1.6 vs. 8.1% of patients; p = 0.008) and parasites (0 vs. 3.3%; p = 0.039), with nonsignificant trend toward fewer bacteria (21.3 vs. 29.2%; p = 0.063). Escherichia coli species were most common in both populations.

Conclusions: Stool PCR identified numerous pathogens in patients with or without celiac disease/inflammatory bowel disease. Patients with celiac disease/inflammatory bowel disease were significantly less likely to have any pathogen identified, and had significantly fewer viruses and parasites. In this population, knowledge of common pathogens can guide diagnostic evaluation and offer opportunities for treatment.