Comparative Evaluation of Conventional Stool Testing and Multiplex Molecular Panel in Outpatients With Relapse of Inflammatory Bowel Disease

Abstract

Background Differentiating between enteric infection and relapse of inflammatory bowel disease (IBD) is a common clinical challenge. Few studies have evaluated the impact of multiplex gastrointestinal polymerase chain reaction (GI PCR) pathogen panels on clinical practice compared to stool culture. Our aim was to compare the impact of PCR stool testing to conventional stool testing in outpatients presenting with relapse of IBD. Methods In a retrospective cohort study of outpatients with IBD presenting to NYU Langone Health with flare from September 2015 to April 2019, we compared patients who underwent stool testing with GI PCR to age-, sex-, and IBD-subtype-matched patients who underwent culture and ova and parasite exam (conventional testing). The primary outcome was IBD therapy escalation after testing. Secondary outcomes included rates of posttesting endoscopy, abdominal radiography, antibiotics, and IBD-related emergency department visits, hospitalizations, and abdominal surgeries. Results We identified 134 patients who underwent GI PCR matched to 134 patients who underwent conventional testing. Pathogens were more frequently identified on GI PCR (26 vs 5%; P < 0.01). We found that GI PCR was associated with less escalation in IBD therapy (16 vs 29%; P < 0.01) and fewer posttest endoscopies (10% vs 18%; P = 0.04), with no differences in IBD outcomes. On multivariate analysis, testing with GI PCR was associated with an odds ratio of 0.26 (95% confidence interval, 0.08-0.84; P = 0.02) for escalation of IBD therapies. Conclusions Testing with GI PCR was associated with higher rates of pathogen detection and lower rates of IBD therapy escalation and endoscopy in the outpatient setting. These changes in management were not associated with a difference in IBD outcomes.

Risk factors and clinical outcomes associated with multiple as opposed to single pathogens detected on the gastrointestinal disease polymerase chain reaction assay

“…24 In a study of GI PCR testing in patients with HIV, Axelrad et al found that 25% of men who have sex with men patients had multiple gut pathogens regardless of their degree of immunosuppression. 11,25 Our study was not powered to look at specific categories of immunosuppression and it is likely that there was heterogeneity in the degree of immunosuppression within the diverse group of immunosuppressed patients included in the study.…”

The role of gastrointestinal pathogens in inflammatory bowel disease: a systematic review

“…Gastrointestinal infections are commonly implicated in relapse (flares) of already established IBD (Table 2). [83][84][85][86][87][88] There is considerable overlap between the clinical presentation of enteric infection and IBD flare, suggesting that these conditions may be mutually exclusive or co-exist, further complicating interpretation and causal determination. Current clinical guidelines recommend testing for C. difficile in all patients with IBD who have worsening or new onset diarrhea and testing for CMV in patients with severe active IBD, particularly if there is concomitant steroid use and disease refractory to medical therapy.…”

The effect of gastrointestinal pathogen panel (GIP) on antibiotic management

“…The utility of GIP in immunocompromised patients has also been documented. In patients with inflammatory bowel disease (IBD), Hong et al 4 showed that GIP testing was associated with increased detection of microbes and lower rates of IBD therapy escalation and endoscopies with no difference in adverse outcomes. GIP testing in hematopoietic stem-cell transplant recipients has been associated with increased identification of infectious pathogens without increasing overall testing cost.…”