Surreal illustration of CMV infection in the colon.

Is CMV Causing Your Ulcerative Colitis Flare-Up? A New Way to Tell

Theo Raines in Health & Wellness November 2025 • 4 min read.

"Discover how a simple clinical model can help detect cytomegalovirus (CMV) infection during ulcerative colitis (UC) exacerbations, leading to faster treatment and better outcomes."

Ulcerative colitis (UC) is a chronic inflammatory condition affecting the colon, characterized by periods of remission and flare-ups. Managing these flare-ups can be challenging, as various factors can trigger them, including infections. One such infection is cytomegalovirus (CMV), a common virus that can reactivate during periods of immune suppression.

While CMV is frequently detected in the colonic biopsies of UC patients, especially those with steroid-refractory UC, its exact role remains controversial. Is it merely an innocent bystander, or does it actively contribute to the worsening of UC symptoms? Distinguishing between these possibilities is critical for determining the appropriate course of treatment.

A recent study published in 'Digestion' provides a promising clinical model to detect CMV infection in UC patients experiencing exacerbations. This model relies on readily available clinical parameters, offering a way to quickly assess the likelihood of CMV involvement and guide timely interventions. Here's a breakdown of the study and its potential implications for managing UC.

The CMV-UC Connection: Unpacking the Research

Surreal illustration of CMV infection in the colon.

The study, led by Avi Levin, Shaul Yaari, and colleagues, retrospectively analyzed data from patients hospitalized for UC exacerbations. The researchers aimed to identify clinical and pathological parameters associated with CMV infection in the colon. They compared various methods for detecting CMV, including histopathology, immunohistochemistry (IHC), and CMV-PCR, to determine the most effective approach.

The study revealed some key findings:

CMV-PCR was the most sensitive method for detecting CMV in colonic tissue, outperforming histopathology and IHC.
CMV-positive patients had a significantly higher frequency of recent steroid treatment and fever.
They also had higher mean partial Mayo scores (indicating more severe disease activity) and lower mean albumin levels.
Multivariate analysis identified recent steroid treatment and fever as independent predictors of colonic CMV infection.

Based on these findings, the researchers developed a clinical model to predict the presence of CMV infection in hospitalized UC patients. This model uses a combination of recent steroid use and the presence of fever to estimate the likelihood of CMV involvement. Notably, patients with both recent steroid treatment and fever had a 100% positive predictive value for CMV infection. In contrast, patients without these factors had a very low risk of CMV.

What This Means for You: A Practical Takeaway

This study offers a valuable tool for clinicians managing UC patients experiencing flare-ups. By incorporating this clinical model into their assessment, doctors can more quickly identify patients at high risk for CMV infection. This, in turn, can lead to earlier initiation of appropriate diagnostic tests, such as CMV-PCR, and timely implementation of antiviral therapy when needed. While further research is always warranted, this clinical model represents a significant step forward in optimizing the management of UC and improving patient outcomes.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1159/000479865, Alternate LINK

Title: Diagnosis Of Cytomegalovirus Infection During Exacerbation Of Ulcerative Colitis

Subject: Gastroenterology

Journal: Digestion

Publisher: S. Karger AG

Authors: Avi Levin, Shaul Yaari, Ronen Stoff, Orit Caplan, Dana G. Wolf, Eran Israeli

Published: 2017-01-01

Everything You Need To Know

In individuals with Ulcerative Colitis (UC), how might Cytomegalovirus (CMV) impact their condition during flare-ups?

The study suggests that Cytomegalovirus (CMV) might contribute to the worsening of Ulcerative Colitis (UC) symptoms during flare-ups, especially in patients with steroid-refractory UC. Identifying whether CMV is an active contributor or merely present is crucial for determining the appropriate treatment course.

How does the clinical model predict the presence of Cytomegalovirus (CMV) infection in hospitalized Ulcerative Colitis (UC) patients?

The clinical model uses readily available clinical parameters such as recent steroid treatment and the presence of fever to assess the likelihood of Cytomegalovirus (CMV) involvement in patients hospitalized for Ulcerative Colitis (UC) exacerbations. Patients with both recent steroid treatment and fever had a 100% positive predictive value for CMV infection.

What methods exist for detecting Cytomegalovirus (CMV) in colonic tissue, and which is considered the most effective in Ulcerative Colitis (UC) patients?

Cytomegalovirus-Polymerase Chain Reaction (CMV-PCR) was identified as the most sensitive method for detecting Cytomegalovirus (CMV) in colonic tissue samples from Ulcerative Colitis (UC) patients. It outperformed both histopathology and immunohistochemistry (IHC) in detecting CMV.

How does the clinical model influence the management and treatment of Ulcerative Colitis (UC) patients experiencing Cytomegalovirus (CMV) infections?

The clinical model, based on recent steroid use and the presence of fever, helps doctors quickly identify Ulcerative Colitis (UC) patients at high risk for Cytomegalovirus (CMV) infection during flare-ups. This allows for earlier initiation of diagnostic tests like Cytomegalovirus-Polymerase Chain Reaction (CMV-PCR) and timely implementation of antiviral therapy, potentially improving patient outcomes.

What are the limitations of the clinical model, and what future research is needed to refine the understanding of the Cytomegalovirus (CMV) and Ulcerative Colitis (UC) connection?

While the clinical model offers a promising approach, it's important to note that further research is warranted to validate its effectiveness across diverse patient populations and settings. Additionally, future studies could explore the underlying mechanisms by which Cytomegalovirus (CMV) interacts with Ulcerative Colitis (UC) to exacerbate symptoms and identify additional clinical or pathological parameters that could enhance the model's predictive accuracy.