Can testing UC patients for two fecal markers, not one, better predict relapse?

Last Updated: 2017-09-15

By Marilynn Larkin

NEW YORK (Reuters Health) - Using both fecal calprotectin (Fcal) and the fecal immunochemical test (FIT) may improve the reliability of relapse prediction in patients with quiescent ulcerative colitis (UC), researchers in Japan suggest.

"Both Fcal and FIT are useful and convenient fecal markers of inflammatory bowel disease," Dr. Sakiko Hiraoka of Okayama University told Reuters Health by email.

"Although Fcal is frequently used in monitoring UC disease activity in Western countries," he observed, "we have reported that FIT can predict mucosal healing more sensitively than Fcal."

Dr. Hiraoka and colleagues recruited 113 UC patients (median age, 46; about half male) in 2014 who were in clinical remission for at least three months. Patients underwent colonoscopy and Fcal and FIT measurement. They were followed for two years after enrollment or until relapse.

A total of 42% of patients relapsed, according to the report in the Journal of Crohn's and Colitis, online August 31.

Fcal positivity (at least 75 micrograms/gram) and FIT positivity (at least 110 ng/mL) each independently predicted clinical relapse (hazard ratios, 2.29 and 2.91, respectively).

Within a year, FIT-positive patients were more vulnerable to relapse (50%) than were FIT-negative patients (roughly 17%), regardless of the FIT-negative patients' Fcal finding. However, by 2 years, Fcal status did influence the relapse rate for FIT-negative patients: 40% if FIT-negative, Fcal-positive; 22% if negative on both tests.

Categorizing patients according to their fecal marker status revealed variations in risk of relapse. With patients who were negative on both tests as the reference group, the HR for relapse was 2.05 in patients who were FIT-negative and Fcal-positive, and 5.43 in those who were FIT-positive (both HRs were statistically significant).

"These results suggest that FIT positivity reflects a different clinical property than Fcal positivity and that the risk of relapse in UC patients in clinical remission could be stratified more efficiently by using both fecal markers," the authors conclude.

"In clinical practice," Dr. Hiraoka said, "we propose to use these two markers (with UC patients) as follows: Patients in clinical remission should undergo FIT first and confirm a negative FIT result, because of its low cost (approximately 10% cost for Fcal) and the high relapse rate of FIT- positive patients."

"FIT-negative patients should be monitored by Fcal at approximately one-year intervals because the relapse rate of patients with FIT-negative and Fcal-positive increases one year after entering remission," he noted. "Appropriate use of fecal markers in UC patients can reduce burdensome colonoscopies and lead a favorable disease course."

Dr. David Hudesman, medical director of the Inflammatory Bowel Disease Center at NYU Langone Health in New York City, told Reuters Health, "The data here support what previous studies have shown - that both fecal calprotectin Fcal and FIT are good biomarkers for relapse. Both tests have flaws, but they are two of the best biomarkers we have."

"This study looked at whether using both tests was possibly more predictive, and although the data were interesting, the study really wasn't powered enough to say definitely," he said by email.

"Additionally," Dr. Hudesman said, "based on the study design, it wasn't clear how adding both tests would affect long-term outcomes."

"Further studies need to be done," he said. "The study had a limited number of participants and it wasn't clear how these patients were treated, so just looking at a one-time measurement of both fecal calprotectin and FIT probably isn't going to be sufficient."

He concluded, "We use stool biomarkers more routinely and the real questions, where we need more research, are how often should we be using these tests and when we get an elevated result, how do we intervene?"

SOURCE: http://bit.ly/2xEyZvs

J Crohns Colitis 2017.