Fecal calprotectin predicts mucosal healing in ulcerative colitis

Last Updated: 2017-06-14

By Will Boggs MD

NEW YORK (Reuters Health) - Fecal calprotectin levels can predict histological healing in patients with ulcerative colitis (UC), a retrospective study suggests.

"Fecal calprotectin (FC) levels can play a significant role in disease monitoring and be used as an alternative to more invasive studies, such as colonoscopies,” Dr. Anish Patel from Carl R. Darnall Army Medical Center, Fort Hood, Texas told Reuters Health by email. “Also, we would like to emphasize that histological healing plays a significant role in activity and can be detected with FC, despite endoscopic inactivity.”

Endoscopy remains the gold standard for assessing UC disease activity, but its invasive nature, high costs, and risk of associated complications make it less than ideal for repeated monitoring. Fecal calprotectin, a surrogate biomarker of inflammation, might be an alternative.

Dr. Patel’s team evaluated the accuracy and clinical utility of FC levels to predict histological remission in their retrospective chart review of 68 patients with UC who had undergone full colonoscopy and had FC results within 6 weeks of the colonoscopy and no evidence of infection.

The median fecal calprotectin level was 247 ug/g, and two-thirds of patients were not in clinical remission based on patient-reported outcome measures (rectal bleeding and stool frequency), according to the June 5 Inflammatory Bowel Diseases online report.

Patients in clinical remission had significantly lower FC levels (50 ug/g) than did those not in remission (409 ug/g), and increasing FC levels were associated with increasing severity of endoscopic activity as defined by the Mayo endoscopic subscore (MES).

FC levels correlated directly with increasing histological inflammatory activity, as determined by the Nancy histological scoring system. FC levels were significantly lower in patients with Nancy 0/1 compared with Nancy 2, 3, and 4.

At a cutoff <60 ug/g, FC showed 87% specificity, 86% sensitivity, 86% positive predictive value, and 87% negative predictive value for deep remission, with an overall accuracy of 0.92 (based on ROC analysis).

“Even with evidence of endoscopic healing, the FC level was sensitive to histological activity, demonstrating that histological activity plays a significant role in the FC level,” Dr. Patel said.

“Based on our findings, we are hoping to provide a noninvasive option with respect to disease monitoring,” he said. “We hope this will allow payers to allow more access to the use of FC levels and hopefully will minimize invasive studies such as colonoscopy in disease monitoring.”

“We are planning a larger study to validate our findings, collaborating with partners both in academic institutions and private practices to simulate more ‘real world’ medicine,” Dr. Patel said.

Dr. Paula Ministro from Tondela-Viseu Hospital Center in Viseu, Portugal, who recently reviewed fecal biomarkers in inflammatory bowel disease, told Reuters Health by email, "Calprotectin levels are already used as surrogate markers of inflammation in clinical practice. They are used in addition to patient-related outcomes and serological markers like CRP to monitor both disease activity and response to treatment.”

“Calprotectin levels are easy to measure in a non-invasive, rapid, and inexpensive manner,” she said. “Still, there are some pitfalls, like interference with drugs such as NSAIDs or proton pump inhibitors (PPIs), variability of measurements during the day, and no capability of differentiating inflammation from infection.”

“More robust data is needed to shift the paradigm from endoscopic remission to histological remission,” Dr. Ministro concluded. “Calprotectin as a surrogate marker of inflammation, with the capacity of accurately predicting histological activity/remission, is an important issue. These results are very promising and shed light on that direction.”

SOURCE: http://bit.ly/2s1pi6e

Inflam Bowel Dis 2017.