Calprotectin in the Updated ACG Ulcerative Colitis Guidelines

Microscope photo of a human large intestine section with inflammation (Colitis).

What is Ulcerative colitis?

Ulcerative colitis (UC) is a chronic disease affecting the large intestine, in which the lining of the colon becomes inflamed and develops tiny open sores, or ulcers. This condition is the result of the immune system’s overactive response.1 This is a disease with increasing incidence worldwide- nearly one million individuals each in the United States and Europe are affected by this condition and many more globally. The management of this disease has grown increasingly complex with the availability of additional classes of therapeutic agents since the last guideline from the American College of Gastroenterology (ACG) was published on this topic.1

What is Calprotectin?

Calprotectin (MRP8/14 or S100A8/A9) also known as fCAL or FC, is a protein found extensively in the cytoplasm of neutrophils. It has been shown to be extremely useful as an aid for diagnosis of inflammatory diseases in the gastrointestinal tract.2

“FC levels correlate with degrees of endoscopic and histologic inflammation in UC and therefore have been proposed as a marker of disease activity to guide treatment. FC levels are more sensitive and specific than serum inflammatory markers and obviously also less invasive than endoscopy or mucosal biopsies, so this assessment has become routine for many clinicians who are managing patients with UC. ” 3

David T. Rubin, MD, FACG, lead a team of experts that established the ACG Clinical Guidelines for Ulcerative colitis, published in the March issue of The American Journal of Gastroenterology

Rubin DT, et al. Am J Gastroenterol. March 2019- Volume 114 – Issue 3 – p 384–413. doi:10.14309/ajg.0000000000000152

Highlights of  Updated Guidelines

According to David T. Rubin MD,FACG:

“Recognizing that the choice of therapies for patients is not only about how sick they are at the time their disease may be active, but also what their prognosis is,” he said. “You can choose therapies based on prognosis even in somebody who may have a milder disease. In consideration of this, we also developed a new disease activity index. The ACG disease activity index for the first time includes urgency as a symptom, which has not been included before, but is obviously a significant symptom in people with ulcerative colitis and it includes endoscopic activity as a component of it, as well as fecal calprotectin.”


  1. Crohn’s & Colitis Foundation. “What is Ulcerative Colitis?” Accessed June 20, 2019.
  2. Nilsen, T. et. al.  A novel turbidimetric immunoassay for fecal calprotectin optimized for routine chemistry analyzers. J Clin Lab Anal. 2016 Sep 15. PMID:27629827
  3. Rubin, David T. et al. ACG Clinical Guideline: Ulcerative Colitis in Adults. American Journal of Gastroenterology. March 2019 – Volume 114 – Issue 3 – p 384–413 doi: 10.14309/ajg.0000000000000152.