Biologics are medications that doctors use to help treat moderate to severe ulcerative colitis (UC), but they do not work for everyone. Biomarker testing may offer a way to predict the body’s response, allowing for more individualized treatment plans.

UC is one of two major inflammatory bowel diseases (IBDs). It occurs when an overactive immune response creates inflammation in the lining of the large intestine. Ulcers form over time, causing a variety of symptoms.

UC severity and experiences can vary significantly between people. Periods of remission — where ulcers heal, and symptoms improve — can complicate diagnosis and treatment.

To gain a more accurate insight into disease severity, experts have turned to biomarkers. These biological measurements not only help indicate UC activity but may also offer insight into biologic treatment options.

This article discusses the role of biomarkers in UC and how they can help direct treatment initiatives.

Biomarkers may be useful tools in predicting the success of treatments known as biologics.

Biologics are therapeutic products made from biological components, such as proteins, sugars, nucleic acids, cells, tissue — or any combination thereof.

Unlike systemic medications that affect the entire body, biologics target specific substances proven to be a part of a disease process. This can result in a reduction in systemic side effects.

In the treatment of UC, biologic medications are anti-tumor necrosis factor (anti-TNF) agents. They work by blocking proteins known to cause inflammation in IBD.

Not everyone responds to biologic treatments for UC, but biomarkers may be able to predict who does and who does not.

A 2021 review in the journal Life (Basel) looked at several common biomarkers for UC and their ability to predict therapeutic response and disease activity.

Of those reviewed, the biomarker fecal calprotectin accurately predicted the therapeutic response to biologics in UC.

A 2017 study in Gastroenterology and Hepatology from Bed to Bench noted that genetic biomarkers, such as IBD risk-increasing IL23R variants, have also been shown to predict response rates to anti-TNF agents.

Biomarkers are biological measurements used to indicate the body’s performance.

Biomarkers can be substances — such as proteins, genes, or enzymes — or functional metrics, such as heart rate, blood pressure, or body temperature.

A biomarker aims to provide an accurate, overall idea of function by viewing a specific, real-time slice of information.

In conditions where disease severity is challenging to determine by outward symptoms, biomarkers offer an accurate assessment tool.

Rather than relying on patient experiences and a wide array of possible symptom presentations in UC, the presence of biomarkers can help determine disease activity and remission.

A 2022 study in BMC Gastroenterology found that the biomarker fecal calprotectin was useful in predicting UC severity in short-term (0–4 years) disease.

Fecal calprotectin is just one of many potential IBD biomarkers that may predict disease activity. A 2021 study in Scientific Reports found 10 serum biomarkers that notably changed based on a person’s state of remission.

Biomarkers may even be able to determine which form of IBD is present without invasive testing in some cases.

Research from 2019 found that T cell biomarkers were able to predict whether IBD was Crohn’s disease or UC.

The most researched biomarkers used in the diagnosis and management of UC are:

  • c-reactive protein (CRP)
  • fecal calprotectin (FP)

Experts have used these to grade inflammation, monitor therapeutic response, and assess remission.

Over time, with the expansion of research, more biomarkers have become known. They include blood, fecal, urine, and genetic components, among many others.

Examples of emerging biomarkers used in IBD and UC include:

  • erythrocyte sedimentation rate (ESR)
  • lactoferrin
  • CD8 T cell transcriptomes
  • fecal immunochemical test (FIT)
  • CD classifier
  • mucosal healing index (MHI)
  • ulcerative colitis response index (UCRI)
  • interleukin
  • IFN-β
  • CXCL9-11
  • S100A8/A9
  • G-CSF
  • Galectin-1
  • TFF3
  • vitamin D

Laboratory testing typically identifies biomarkers. In UC, FP is obtained from fecal testing, while CRP is via blood testing.

Urine samples and genetic testing may also be ways to gather UC biomarkers.

Biomarkers are innovative and may soon offer substitutes for invasive procedures.

However, none are currently proven to be better alternatives to traditional endoscopy.

In addition, individual biomarkers lack specificity. For example, CRP can measure inflammation but cannot determine if it is from IBD or another cause.

Biomarker testing can also be expensive. A 2018 study in Clinical Gastroenterology and Hepatology estimates that biomarker testing for irritable bowel syndrome with diarrhea can be more than $846. The researchers advise that this is not cost-effective, even if it is 100% accurate in diagnosing this condition.

Additionally, the process of testing can take a few weeks, which can delay the start of treatment.

In addition to identifying new biomarkers for UC, future research aims to discover and create biomarker profiles.

These assessment tools would combine multiple UC biomarkers to help create a more accurate picture of what is happening inside the body.

With better insight comes the potential to provide more pinpoint treatment and simultaneous biologic targeting of multiple underlying factors in UC.

UC is an inflammatory bowel disease. While endoscopy remains the most definitive form of diagnosis and assessment, biomarkers can offer insight into treatment response, disease activity, and remission.

FP and CRP are the two most common biomarkers for UC. FP is a possible predictor of biologic treatment success.

Emerging research suggests many other biological measurements may soon help monitor IBD conditions.