Natural history of cytomegalovirus infection in a series of patients diagnosed with moderate-severe ulcerative colitis

Cytomegalovirus in ulcerative colitis: an evidence-based approach to diagnosis and treatment

INTRODUCTION

The detection of cytomegalovirus (CMV) in the setting of inflammatory bowel disease often creates confusion whether CMV is a 'bystander' or 'disease.'

AREAS COVERED

This review discusses the clinical conundrum of CMV in ulcerative colitis, approach to discriminate infection from disease, and therapeutic considerations (immunosuppressive and anti-CMV treatment). CMV disease should be considered in corticosteroid refractory- dependent and thiopurine refractory disease. Endoscopy may reveal deep punched out ulcers, irregular ulcers, or cobble-stoning. The diagnosis rests on the presence and abundance of viral inclusion bodies on hematoxylin and eosin stain, positive immunohistochemistry, and/or positive tissue polymerase chain reaction. CMV disease is associated with worse outcomes including increased colectomy rates.

EXPERT OPINION

The timing and duration of antiviral drugs in CMV disease is debatable but depends on the load of CMV in tissue. In high-grade infection, CMV needs to be treated while increasing immunosuppression may work in the setting of low-grade infection. Ganciclovir is the drug of choice for treatment of CMV disease. Tumor necrosis factor inhibitors may be useful for treating underlying disease activity in the setting of CMV. Other emerging therapies include fecal microbiota transplantation. Randomized studies are necessary to define the best timing and duration of anti-CMV therapy.

Effects of tissue cytomegalovirus quantitative polymerase chain reaction in the management of ulcerative colitis flare-ups: Should we wave aside?

BACKGROUND AND STUDY AIMS

The role of cytomegalovirus (CMV) infection for disease reactivation in ulcerative colitis (UC) patients remains controversial and diagnostic tests are yet to be standardized. We aimed to define the clinical relevance of CMV detection by mucosal polymerase chain reaction (PCR) in UC patients by comparing the clinical course of UC in CMV-treated and CMV-untreated groups in tissue CMV-PCR positive cases.

PATIENTS AND METHODS

In this retrospective study, 141 patients diagnosed with moderate-to-severe UC admitted to our clinic with disease flare, colonic tissue CMV PCR was assessed.

RESULTS

The median age of the study population was 39 years, and 99 (70.2%) patients were male. Eighty-eight (62.4%) patients were CMV-PCR (+) and 53 (37.6%) were CMV PCR (-). The CMV-PCR (+) and CMV PCR (-) groups showed no significant difference concerning age, sex, disease duration, site of involvement and disease activity and administered treatments. The median tissue CMV-PCR was 41,098 IU/mL (IQR:2,344.25-136,192). Thirty-four of 88 CMV-PCR (+) patients received antiviral therapy. The tissue CMV-PCR level of patients who received antiviral therapy was 124,381 IU/mL (IQR: 19,309-412,335), and it was 6,292 IU/mL (IQR: 997-71,154) in patients who did not receive antiviral therapy; (p < 0.001). Sixteen (47.1%) of 34 patients who received antiviral therapy achieved remission. Two of the non-responders underwent colectomy (one because of dysplasia and one who did not respond subsequent biologic agent either). Remaing 16 achieved remission by escalating the immunsuppresive/biologic agent therapy.

CONCLUSION

CMV infection is responsible for only a minority of cases of UC flares and all are steroid-resistant cases. Most of the patients non-responsive to antiviral treatment respond to increased anti-inflammatory treatment. Hesitancy in the decision of escalating immunsuppresive treatment rather than CMV disease may be responsible for worsening disease course and increased colectomy rate in a significant number of the patients who are tissue CMV-PCR (+).

Risk Factors of Cytomegalovirus Reactivation in Ulcerative Colitis Patients: A Meta-Analysis

Cytomegalovirus (CMV) infection is associated with exacerbation of disease activity in patients with ulcerative colitis (UC). However, the risk factors for CMV reactivation in this population remain debatable. This meta-analysis was performed to identify the risk factors for CMV reactivation in UC patients. PubMed, Cochrane Library, EMBASE, Web of Science, and China National Knowledge Infrastructure were searched from the inception of these databases to 31 August 2021, with the aim of identifying studies that investigated the risk factors of CMV reactivation in UC patients. A quality assessment of the included studies was performed with the Newcastle-Ottawa Scale. The publication bias was assessed respectively via a funnel plot and Egger’s regression asymmetry test. The robustness and reliability of each outcome were evaluated by sensitivity analysis. Twenty studies were included in the final meta-analysis, comprising a total of 2099 patients with UC. A significantly higher risk of CMV reactivation was observed in patients with severe UC (OR = 1.465, 95% CI: 1.107 to 1.939, p = 0.008), pancolitis (OR = 2.108, 95% CI: 1.586 to 2.800, p = 0.0001), older age of UC onset (MD = 6.212, 95% CI: 2.552 to 9.971, p = 0.001), as well as use of glucocorticoids (OR = 4.175, 95% CI: 3.076 to 5.666, p = 0.001), immunosuppressants (OR = 1.795, 95% CI: 1.289 to 2.501, p = 0.001), and azathioprine (OR = 1.444, 95% CI: 1.012 to 2.061, p = 0.043). However, infliximab treatment was observed not to increase the occurrence of CMV reactivation in patients who suffered from UC. In contrast, 5-aminosalicylic acid (OR = 0.674, 95% CI: 0.492 to 0.924, p = 0.014) was associated with a lower risk of CMV reactivation. Patients with UC should be closely monitored for risk factors of CMV reactivation in order to provide timely diagnosis and antiviral treatment.

Ulcerative Colitis and Cytomegalovirus Infection: From A to Z

Despite multiple studies, the role of cytomegalovirus [CMV] infection in exacerbating the severity of inflammation in ulcerative colitis [UC], and its response to treatment, remain debatable. Additionally, the optimal diagnostic tests for CMV infection in the setting of UC relapse, and timing of antiviral treatment initiation, remain unclear. The challenge faced by gastroenterologists is to differentiate between an acute UC flare and true CMV colitis. It seems that the presence of CMV colitis, as defined by the presence of intranuclear or intracellular inclusion bodies on haematoxylin and eosin [H&E] staining and/or positive immunohistochemistry [IHC] assay on histology, is associated with more severe colitis. Patients with CMV infection and acute severe colitis are more resistant to treatment with corticosteroids than non-infected patients. This refractoriness to steroids is related to colonic tissue CMV viral load and number of inclusion bodies [high-grade CMV infection] which may have a pronounced effect on clinical outcomes and colectomy rates. Whereas many studies showed no effect for antiviral treatment on colectomy rates in CMV-infected UC patients, there was a significant difference in colectomy rates of patients with high-grade infection who received anti-viral therapy compared with those who did not receive treatment. It was therefore proposed that high-grade CMV disease indicates that the virus is acting as a pathogen, whereas in those with low-grade CMV disease, the severity of IBD itself is more likely to influence outcome. The different algorithms that have been put forward for the management of patients with UC and concomitant CMV infection are discussed.

Efficacy of antiviral treatment in cytomegalovirus detected ulcerative colitis: meta-analysis of available data

Aim: This meta-analysis aimed to pool available data regarding the efficacy of ganciclovir treatment among cytomegalovirus-detected ulcerative colitis patients.Methods: We screened PubMed, Ovid, Web of Science and Cochrane databases for relevant studies, and four investigators independently evaluated the studies for eligibility. The primary outcome was surgical resection or death from ulcerative colitis. The data were then pooled via DerSimonian-Laird estimator and Mantel-Haenszel (MH) method, two points added for continuity correction and random-effects model fitted in the Bayesian framework. We first constructed a Bugs model with Student t-distribution as prior for between-study heterogeneity. The model was fitted by Gibbs sampler (JAGS) to produce a marginal posterior distribution.Results: Our screening identified 15 eligible studies for final data synthesis and combined data from 191 ganciclovir-treated and 166 non-treated patients. Effect estimates from the fixed-effects meta-analysis model did not encourage ganciclovir treatment (OR, 1.43; 95% CIs [0-95, 2.16]), with a negligible unaccounted heterogeneity (I² = 0%). The Bayesian random-effects model generated high-density credible intervals, suggesting a high probability, that future studies will also not encourage ganciclovir treatment (mu, 1.028; 95% credible intervals [0.054, 2.238]; 80% credible intervals [0.401, 1.703]) which indicates that future studies will favor non-treatment of ulcerative colitis with ganciclovir.Conclusions: Data produced in this study do not encourage ganciclovir treatment for UC patients. However, studies included in this analysis were observational, and thus, inherited severe selection bias. We suggest randomized controlled studies be conducted to make firm recommendations in this context.

Cytomegalovirus infection associated with inflammatory bowel disease

Refractory colitis in patients with inflammatory bowel disease is a complicated clinical disorder that might, in some patients, even necessitate surgery. Hence the diagnosis of additional complications is of utmost importance. Colitis mediated by cytomegalovirus is one such complication. The high seroprevalence and latent nature of cytomegalovirus, with the possibility of viral replication without mediating disease, poses a real challenge for the diagnosis of cytomegalovirus-mediated colitis. The challenge in daily clinical practice is to distinguish cytomegalovirus replication from cytomegalovirus-mediated colitis in patients with inflammatory bowel disease who have refractory colitis. This Review discusses the scientific literature and provides a diagnostic and therapeutic algorithm for clinical practice.

Diagnostic utility of quantitative cytomegalovirus DNA polymerase chain reaction in intestinal biopsies from patients with inflammatory bowel disease

OBJECTIVES

Diagnostic utility of cytomegalovirus (CMV) DNA quantitative polymerase chain reaction (qPCR) in inflammatory bowel disease (IBD) has not been established. We aimed to compare diagnostic utility of qPCR for CMV in biopsy specimens with blood, serology, and histopathology.

MATERIALS AND METHODS

A total of 132 patients were included (92 ulcerative colitis [UC], 9 Crohn's disease, and 31 unclassified IBD). Comparison between CMV IgM, CMV DNA qPCR in biopsy, in blood and histopathology was done. Positive result in any of the test was considered as CMV infection. Various risk factors for CMV association with IBD were analyzed.

RESULTS

Confirmed CMV infection was seen in 41 (31.1%) patients. Diagnostic sensitivity of different assays was: DNA in biopsy seen in 37 (90.2%), DNA in blood in 19 (46.3%), CMV IgM in 15 (36.5%), and histopathology in 8 (19.5%). Thirty-two UC cases were further followed up for a median time of 14.0 (R: 3-31) months. They were grouped as group I - biopsy and blood DNA both positive (14, 43.7%), Group II - biopsy positive and blood negative (17, 53.1%), and Group III - biopsy negative but blood positive (1, 3.1%). CMV DNA viral load in Group I was significantly higher (mean: 4.2 ± 1.0 log₁₀ copies/mg) than Group II (mean: 3.2 ± 0.6 copies/mg) and Group III (viral load: 2.69 log₁₀ copies/ml), P < 0.001. Steroid refractoriness was seen more in Group I cases (n = 9) P < 0.001. A cutoff of ≥2.5 log₁₀ copies/mg of DNA in tissue was predictive for steroid refractoriness (AUROC = 0.84).

CONCLUSIONS

Quantitation of CMV DNA in intestinal biopsy is a useful diagnostic tool and can predict response to steroid treatment in patients with UC.

Is cytomegalovirus infection related to inflammatory bowel disease, especially steroid-resistant inflammatory bowel disease? A meta-analysis

BACKGROUND

Human cytomegalovirus (HCMV) infection has been associated with inflammatory bowel disease (IBD). Numerous studies have been conducted to analyze the association between HCMV infection and risk of IBD and steroid-resistant IBD, but no clear consensus had been reached.

OBJECTIVES

The aim of this study was to confirm this relationship precisely by doing a systematic review and meta-analysis.

STUDY DESIGN

We identified relevant studies through a search of PubMed and Embase. Studies were eligible for inclusion if they 1) evaluated the association between HCMV infection and IBD disease; 2) evaluated the association between HCMV infection and steroid-resistant IBD disease; 3) were case-control studies or nested case-control studies; 4) provided the numbers (or percentage) of positivity for HCMV infection in cases and controls, respectively. Data were extracted and analyzed independently by two investigators.

RESULTS AND CONCLUSION

A total of 18 studies including 1,168 patients and 951 health groups was identified, and HCMV infection was distinctly confirmed as a risk factor for the occurrence and development of IBD. When involving 17 studies including 1,306 IBD patients, a total of 52.9% of patients in the cytomegalovirus (CMV)-positive groups were observed to have steroid resistance, compared with 30.2% of patients in the CMV-negative groups. There was a significant difference in the risk of steroid resistance between people exposed to HCMV infection and those not exposed HCMV infection in IBD patients. This meta-analysis suggested that HCMV infection is associated with an increased risk for IBD and steroid-resistant IBD.

Toward an Algorithm for the Diagnosis and Management of CMV in Patients with Colitis

INTRODUCTION

Concurrent cytomegalovirus (CMV) in inflammatory bowel disease-related colitis is an important yet complex clinical scenario associated with high rates of colectomy and other morbidity. This review aimed to examine the literature to produce a comprehensive diagnostic and treatment algorithm for the management of CMV in patients with colitis.

METHODS

A systematic literature review was conducted via PubMed/Medline databases until August 31, 2015, using multiple keywords in English language and where original data only presented.

RESULTS

This review discusses the concept of CMV reactivation which frequently occurs in inflammatory bowel disease-related colitis, most commonly in those presenting with steroid-refractory colitis. In this context, although signifying a poorer prognosis, in most cases, the virus is nonpathogenic and thus antiviral treatment is unhelpful. However, when reactivation gives rise to true CMV disease (colitis) as best discriminated by histology with immunohistochemistry (and the density of such) in colonic biopsy tissue, the patient does benefit from antivirals.

CONCLUSION

Diagnostic-based patient selection and treatment is integral to optimal outcomes in CMV, and therefore we propose an algorithm based on these concepts that now requires prospective evaluation.

Active cytomegalovirus infection diagnosed by real-time PCR in patients with inflammatory bowel disease: a prospective, controlled observational study (.)

OBJECTIVE

It is assumed that cytomegaloviral (CMV) infection in inflammatory bowel disease (IBD) is caused by reactivation due to the immunosuppressive therapy, but the role of CMV as a pathophysiological factor and prognostic marker in IBD is unclear. The aim of this study was to investigate CMV infection in IBD, with real-time polymerase chain reaction (PCR) and immunohistochemistry, with emphasis on newly diagnosed disease.

MATERIALS AND METHODS

In this prospective, controlled study, 67 patients with IBD and 34 control patients with irritable bowel syndrome (IBS) or rectal bleeding were included. Serology for CMV was analysed along with CMV DNA in plasma, mucosal biopsies, and faeces. Mucosal biopsies were further analysed with histopathology and CMV immunohistochemistry.

RESULTS

Detection of CMV IgM was more common in patients with IBD, compared to controls, 21% versus 3%. CMV DNA was found in 16% of patients with newly diagnosed, untreated IBD and in 38% of steroid-treated patients. Four of the five patients that needed urgent surgery were CMV-DNA positive in at least one of three sample types. None of the controls had detectable CMV DNA.

CONCLUSIONS

Active CMV infection was found in high proportions of newly diagnosed untreated patients with IBD, in patients on immunosuppression and in patients in the need of surgery. Low CMV-DNA levels in non-immunosuppressed patients were not a risk factor for the development of more severe IBD, while the detection of CMV DNA in patients on immunosuppressive therapy may foresee disease progression.

Role of intestinal flora imbalance in pathogenesis of pouchitis

OBJECTIVE

To discuss the role of intestinal flora imbalance in the pathogenesis of pouchitis.

METHODS

The pouchitis rat model was established and the faeces sample and the mucous membrane sample were collected regularly, in which the bacterial nucleic acids were extracted for quantitative analysis of the intestinal flora in the samples through using the real-time quantitative PCR technique and high energy sequencing technology.

RESULTS

The disorder phenomenon of the intestinal flora appeared at the 7th day of the experiment, and the pouchitis was presented at the 21st day of the experiment. At the 31st day of the experiment, compared to control group and non-pouchitis group, the quantity of Bifidobacterium and the Lactobacillus of the pouchitis model rats in the mucous membrane sample and the faeces sample were significantly decreased (P < 0.05), and the Bacteroidetes, Faecalibacterium prausnitzii and XIV Clostridium leptum subgroup in the mucous membrane of pouchitis were significantly decreased (P < 0.05). The IV Clostridium coccoides group was the main flora in the mucous membrane of pouchitis, the bacterial diversity of non-pouchitis group and control group was significantly higher than that of the pouchitis group (P < 0.05).

CONCLUSIONS

The intestinal flora imbalance is one of the factors that cause the incidence of the pouchitis; this study provides a clue of the pathogenesis and treatment direction of the intestinal inflammatory disease.

Cytomegalovirus and ulcerative colitis: Place of antiviral therapy

The link between cytomegalovirus (CMV) infection and inflammatory bowel diseases remains an important subject of debate. CMV infection is frequent in ulcerative colitis (UC) and has been shown to be potentially harmful. CMV reactivation needs to be diagnosed using methods that include in situ detection of viral markers by immunohistochemistry or by nucleic acid amplification techniques. Determination of the density of infection using quantitative tools (numbers of infected cells or copies of the genome) is particularly important. Although CMV reactivation can be considered as an innocent bystander in active flare-ups of refractory UC, an increasing number of studies suggest a deleterious role of CMV in this situation. The presence of colonic CMV infection is possibly linked to a decreased response to steroids and other immunosuppressive agents. Some treatments, notably steroids and cyclosporine A, have been shown to favor CMV reactivation, which seems not to be the case for therapies using anti-tumor necrosis factor drugs. According to these findings, in flare-ups of refractory UC, it is now recommended to look for the presence of CMV reactivation by using quantitative tools in colonic biopsies and to treat them with ganciclovir in cases of high viral load or severe disease.

Cytomegalovirus in inflammatory bowel disease: A systematic review

AIM

To identify definitions of cytomegalovirus (CMV) infection and intestinal disease, in inflammatory bowel disease (IBD), to determine the prevalence associated with these definitions.

METHODS

We conducted a systematic review and interrogated PubMed, EMBASE and Cochrane for literature on prevalence and diagnostics of CMV infection and intestinal disease in IBD patients. As medical headings we used "cytomegalovirus" OR "CMV" OR "cytomegalo virus" AND "inflammatory bowel disease" OR "IBD" OR "ulcerative colitis" OR "colitis ulcerosa" OR "Crohn's disease". Both MeSH-terms and free searches were performed. We included all types of English-language (clinical) trials concerning diagnostics and prevalence of CMV in IBD.

RESULTS

The search strategy identified 924 citations, and 52 articles were eligible for inclusion. We identified 21 different definitions for CMV infection, 8 definitions for CMV intestinal disease and 3 definitions for CMV reactivation. Prevalence numbers depend on used definition, studied population and region. The highest prevalence for CMV infection was found when using positive serum PCR as a definition, whereas for CMV intestinal disease this applies to the use of tissue PCR > 10 copies/mg tissue. Most patients with CMV infection and intestinal disease had steroid refractory disease and came from East Asia.

CONCLUSION

We detected multiple different definitions used for CMV infection and intestinal disease in IBD patients, which has an effect on prevalence numbers and eventually on outcome in different trials.

Detection of Cytomegalovirus in Patients with Inflammatory Bowel Disease: Where to Biopsy and How Many Biopsies?

BACKGROUND

The potential negative impact of cytomegalovirus (CMV) in ulcerative colitis (UC) and Crohn's disease (CD) warrants efforts to improve the yield of diagnostic techniques.

METHODS

We retrospectively determined the optimal biopsy location and number from sixty-eight patients with inflammatory bowel disease (66% UC, 31% CD, and 3% inflammatory bowel disease-unclassified) with CMV disease between 2005 and 2011. Biopsies with endoscopic and histologic inflammation were analyzed by immunohistochemistry and/or in situ hybridization. The proportion of positive biopsies was determined, and using data from the 25th percentile, we assessed the number of biopsies required to achieve an 80% probability of a single positive biopsy.

RESULTS

Of the patients with a diagnosis by immunohistochemistry and/or in situ hybridization, 27 of 61 (44%; 95% confidence interval, 32-57) were positive by hematoxylin and eosin, and 11 of 36 (31%; 95% confidence interval, 16-46) had systemic CMV by polymerase chain reaction. Of the patients with biopsies proximal and distal to the splenic flexure, 1 of 11 with UC and 4 of 8 with CD had a diagnosis limited to the right colon. Twenty percent of biopsies were positive by immunohistochemistry or in situ hybridization (20% in UC and 17% in CD). Eleven biopsies in UC and 16 in CD were required to achieve an 80% probability of a positive biopsy.

CONCLUSIONS

Biopsy location and number are important considerations when assessing for CMV. We recommend a flexible sigmoidoscopy with 11 biopsies in UC and a colonoscopy with 16 biopsies in CD.

Antiviral Therapy in Steroid-refractory Ulcerative Colitis with Cytomegalovirus: Systematic Review and Meta-analysis

BACKGROUND

The role of antiviral therapy in patients with ulcerative colitis (UC) with cytomegalovirus (CMV) remains unclear. We therefore performed a systematic review and meta-analysis to assess the association between antiviral therapy and the risk of colectomy.

METHODS

Multiple electronic databases were searched systematically through July 2014 for studies reporting the risk of colectomy in patients with UC with CMV stratified by treatment with antiviral agents. Colectomy rates were assessed for the overall cohort and stratified by corticosteroid (CS) refractoriness. We estimated summary odds ratios and 95% confidence intervals, using random-effects model, and used Grading of Recommendations Assessment, Development, and Evaluation criteria to appraise the quality of evidence.

RESULTS

Fifteen observational studies (333 patients with UC with CMV, 43.2% treated with antiviral agents) were identified, of which 8 stratified patients according to CS-refractory disease (55.4% treated with antiviral agents). Antiviral therapy resulted in a significantly lower risk of colectomy in patients with CS-refractory disease (odds ratio, 0.20; 95% confidence interval, 0.08-0.49; I = 0%) but not in the overall population of patients with UC (odds ratio, 0.92; 95% confidence interval, 0.31-2.76; I = 65). The quality evidence was low. The results were stable when restricting the analysis to patients with a tissue diagnosis of CMV and studies that defined CS-refractory disease as a failure to respond to intravenous CS.

CONCLUSIONS

Antiviral therapy may benefit a subgroup of patients with UC who are refractory to CS. Further prospective trials are required to confirm these findings.

Relationship between cytomegalovirus infection and inflammatory bowel disease

Human cytomegalovirus (HCMV) is a common opportunistic pathogenic virus, which causes dormant or latent infection following primary infection in immunocompetent individuals and overt infection in immunocompromised patients. Inflammatory bowel disease (IBD) is a chronic, recurrent inflammatory illness and patients with IBD are often immunosuppressed, through combined action of potentially malnutrition, use of immunosuppressants, etc. These factors predispose patients with IBD to an increased risk of developing HCMV infection. The number of IBD patients with concomitant HCMV infection is increasing and the adverse role of HCMV in IBD has drawn much attention from clinicians. Recent evidence suggests that HCMV may play an essential role in the progression of IBD, and elucidating the possible association between HCMV infection and IBD as well as the underlying mechanisms has great diagnostic and therapeutic implications. Here we review the possible relationship between HCMV and IBD.

Relationship Between Cytomegalovirus Infection and Steroid Resistance in Inflammatory Bowel Disease: A Meta-Analysis

BACKGROUND AND AIMS

Steroid resistance presents an administration difficulty in inflammatory bowel disease (IBD). The reason of steroid resistance is still unclear, but cytomegalovirus (CMV) infection may be a potential cause in some IBD patients. We carried out a meta-analysis to investigate the relationship between CMV infection and steroid-resistant IBD.

METHODS

The PubMed, EMBASE, and Cochrane Library databases were searched up to June 2014, with no language restrictions, for observational studies. Additional references were obtained from reviewed articles.

RESULTS

Eleven studies involving 867 IBD patients were included in the meta-analysis. Steroid resistance rate was 70.0% in CMV-positive IBD patients, which was significantly higher than that in CMV-negative IBD patients (RR = 2.12, 95% CI = 1.72-2.61). There was significant heterogeneity in the included eleven studies (I (2) = 57.6%). When the only one study with a few patients was excluded, sensitivity analysis suggested a similar outcome (RR = 2.07, 95% CI = 1.80-2.39, 10 studies). Based on the funnel plot and Egger's test, we considered that there was a probable publication bias.

CONCLUSION

Our meta-analysis suggests that CMV-positive IBD patients have a nearly double risk of steroid resistance compared with CMV-negative IBD patients, indicating that CMV infection is a probable cause of steroid-resistant IBD.

Relationship between human cytomegalovirus infection and refractory ulcerative colitis: A meta-analysis

AIM: To investigate the relationship between human cytomegalovirus (HCMV) infection and refractory ulcerative colitis (UC), and evaluate the necessity of antiviral therapy in refractory UC patients with HCMV infection.

METHODS: We searched Medline, PubMed, CNKI and Wanfang databases till 2013 to retrieve relevant studies. Meta-analyses were performed for the included case-control studies using RevMan4.2 software after strict screening to estimate odds ratio (OR) and 95% confidence interval (CI) for the association between HCMV infection and refractory UC. We also performed heterogeneity test, sensitivity analysis and publication bias assessment.

RESULTS: Eighteen eligible studies, including 15 carried out by foreigners and 3 by Chinese researchers, were included in the meta-analysis, involving 831 patients with UC. Seven included studies were analyzed at both blood and intestinal tissue levels. Six studies on HCMV infection and refractory UC were also collected for analysis at intestinal tissue level. The results of meta-analysis showed that there was a significant difference in the HCMV infection rate between patients with refractory UC and health controls (OR = 10.62, 95%CI: 4.79-23.54, P < 0.00001). At the blood level, three studies on HCMV infection and refractory UC were collected. It was showed that there was a significant difference in the HCMV infection rate between patients with refractory UC and health controls (OR = 3.22, 95%CI: 1.48-7.00, P = 0.003). Six studies on patients with active UC who were infected with HCMV and non-responsive to steroids were collected. The results of meta-analysis showed that the incidence of hormone resistance in patients with refractory UC was positively correlated with the HCMV infection rate (OR = 8.88, 95%CI: 4.43-17.17, P < 0.00001). Three studies on whether antiviral therapy could increase platelet count in patients with refractory UC were collected. It was showed that the group treated by antiviral therapy was superior to others in the response rate (OR = 7.53, 95%CI: 1.59-35.72, P = 0.01). Funnel plot analysis indicated the existence of publication bias.

CONCLUSION: Patients with refractory UC undergoing steroid treatment are susceptible to HCMV infection. In the presence of HCMV, UC becomes more complex. Patients with active UC who are infected with HCMV are usually non-responders to steroids. The prompt application of antiviral therapy can significantly improve the condition of patients with refractory UC. High quality, multi-center, prospective randomized controlled studies are needed to confirm our findings.

Diagnosis and management of common gastrointestinal tract infectious diseases in ulcerative colitis and Crohn's disease patients

Management of inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, stretches beyond control of flares. Some infections of the gastrointestinal tract are more commonly seen in patients with IBD. Work from the Human Microbiome Project has been instrumental in our understanding of the interplay between the vast gut microbiota and host immune responses. Patients with IBD may be more prone to infectious complications based on their underlying inflammatory disease and variations in their microbiome. Immunosuppressant medications commonly used to treat patients with Crohn's and colitis also play a role in predisposing these patients to acquire these infections. Here, we present a detailed review of the data focusing on the most common infections of the gastrointestinal tract in patients with IBD: Clostridium difficile infections (CDI) and cytomegalovirus (CMV). We will discuss appropriate diagnostic tools and treatment options for these infections. Other less common infections will also be reviewed briefly. Studying the various infections of the gastrointestinal tract in these patients could enhance our understanding of the pathophysiology of IBD.

Long-term outcome of inflammatory bowel diseases with cytomegalovirus colitis: effect of antiviral treatment

OBJECTIVE

The role of cytomegalovirus (CMV) reactivation in the outcome of inflammatory bowel diseases (IBDs) is unclear. Uncertainties remain on the treatment of CMV infection, especially in patients with a viral load just above the normal value in the blood or with very few positive cells in colonic biopsies. This retrospective cohort study reports the long-term outcome of 38 active IBD patients with CMV infection, 13 of whom received an antiviral treatment.

PATIENTS AND METHODS

Thirty patients with ulcerative colitis (UC) and eight patients with Crohn's colitis with active colitis and CMV infection, diagnosed by detection of at least one CMV inclusion by histology and immunohistochemistry and/or with the CMV antigen test or the CMV DNA test, were studied. Their clinical history at 6 months and up to 1 year following hospital discharge was reviewed. Clinical remission at hospital discharge and recurrences requiring new treatments or colectomy were considered major outcomes of the study. The features of treated and untreated patients were compared using the Fisher exact test and the Student t-test.

RESULTS

All patients showed rare CMV inclusions, and only three had positive blood CMV PCR. Thirteen patients received antiviral treatment, whereas 25 patients did not. No patient underwent colectomy during the hospitalization. The 12-month cumulative rate of clinical relapse requiring new treatment or colectomy was 23% in patients treated with antivirals and 50% in untreated patients (P=0.165). However, in patients with UC and in those with steroid-dependent/refractory disease, antiviral treatment was associated with a significantly higher clinical remission rate at 12 months (77.8 vs. 45%, P=0.049, and 77.8 vs. 19.4%, P=0.038, respectively).

CONCLUSION

In IBD patients with active CMV colitis, antiviral treatment seems to have a marginal impact in the short term, during the treatment of the acute phase, but it may have some beneficial effect in maintaining remission up to 1 year of follow-up in patients with UC and steroid-dependent/refractory disease.

Antiviral therapy in cytomegalovirus-positive ulcerative colitis: A systematic review and meta-analysis

AIM: To evaluate the impact of antiviral treatment on cytomegalovirus (CMV)-positive ulcerative colitis patients.

METHODS: We performed a systematic review and meta-analysis (MA) of comparative cohort and case-control studies published between January 1966 and March 2013. Studies focusing on colectomy series and studies including only less than 3 patients in the treated or non-treated arm were excluded. The primary outcome was colectomy within 30 d of diagnosis. Secondary outcomes included colectomy during the follow-up period Subgroup analyses by method of detection of CMV, study design, risk of bias and country of origin were performed. Quality of studies was evaluated according to modified New-Castle Ottawa Scale.

RESULTS: After full-text review, nine studies with a total of 176 patients were included in our MA. All the included studies were of low to moderate quality. Patients who have received antiviral treatment had a higher risk of 30-d colectomy (OR = 2.40; 95%CI: 1.05-5.50; I² = 37.2%). A subgroup analysis including only patients in whom CMV diagnosis was based did not demonstrate a significant difference between the groups (OR = 3.41; 95%CI: 0.39-29.83; I² = 56.9%). Analysis of long-term colectomy rates was possible for 6 studies including 110 patients. No statistically significant difference was found between the treated and untreated groups (OR = 1.71; 95%CI: 0.71-4.13; 6 studies, I² = 0%). Analysis of mortality rate was not possible due to a very limited number of cases. Stratification of the outcomes by disease severity was not possible.

CONCLUSION: No positive association between antiviral treatment and a favorable outcome was demonstrated. These findings should be interpreted cautiously due to primary studies’ quality and potential biases.

Cytomegalovirus: a probable cause of steroid-refractory ulcerative colitis

Cytomegalovirus, regarded as a trigger of several autoimmune diseases, is an opportunistic pathogen. Patients with ulcerative colitis (UC) undergoing steroid treatment are susceptible to this infection. In the presence of cytomegalovirus, inflammation becomes more complex. Patients with active UC who are infected with cytomegalovirus are usually non-responders to steroid, while antiviral drugs could induce remission. Cytomegalovirus should be suggested as a probable cause of steroid-refractory UC based on the clinical data in the literatures.

Clinical significance of cytomegalovirus infection in patients with inflammatory bowel disease

Cytomegalovirus (CMV) infection is common in humans. The virus then enters a “latency phase” and can reactivate to different stimuli such as immunosuppression. The clinical significance of CMV infection in inflammatory bowel disease is different in Crohn’s disease (CD) and ulcerative colitis (UC). CMV does not interfere in the clinical course of CD. However, CMV reactivation is frequent in severe or steroid-resistant UC. It is not known whether the virus exacerbates the disease or simply appears as a bystander of a severe disease. Different methods are used to diagnose CMV colitis. Diagnosis is classically based on histopathological identification of viral-infected cells or CMV antigens in biopsied tissues using haematoxylin-eosin or immunohistochemistry, other tests on blood or tissue samples are currently being investigated. Polymerase chain reaction performed in colonic mucosa has a high sensitivity and a positive result could be associated with a worse prognosis disease; further studies are needed to determine the most appropriate strategy with positive CMV-DNA in colonic mucosa. Specific endoscopic features have not been described in active UC and CMV infection. CMV colitis is usually treated with ganciclovir for several weeks, there are different opinions about whether or not to stop immunosuppressive therapy. Other antiviral drugs may be used. Multicenter controlled studies would needed to determine which subgroup of UC patients would benefit from early antiviral treatment.

Progress in understanding the relationship between inflammatory bowel disease and human cytomegalovirus infection

Human cytomegalovirus (HCMV) is a ubiquitous DNA virus that can cause severe disease in immunosuppressive or immunocompromised patients. Recent studies have found that CMV might play a role in the pathogenesis and progression of inflammatory bowel disease (IBD). This paper gives a review of the epidemiology, clinical diagnosis, and pathogenesis of HCMV infection in patients with IBD.

Management of cytomegalovirus infection in inflammatory bowel diseases

Cytomegalovirus is a deoxyribonucleic acid virus that infects a large part of the human population; after primary infection, it develops a latent state and can be reactivated, notably after a decrease in host immune defences. In patients with inflammatory bowel diseases, cytomegalovirus is frequently involved, either as an agent of colitis or through local asymptomatic reactivation. Due to the immune context of inflammatory bowel diseases and to the immunosuppressive therapies that are used to treat them, cytomegalovirus entertains complex relationships with these diseases. Whereas Crohn's disease seems little impacted by cytomegalovirus, this agent interferes strongly with the natural progression of ulcerative colitis. While immune treatments have a clear influence on the occurrence of cytomegalovirus colitis in ulcerative colitis (favourable for steroids and cyclosporine and rather inhibitory for infliximab), the role of cytomegalovirus infection on ulcerative colitis is more debated with roles ranging from innocent bystander to key pathogen suggested. There is however growing evidence for a participation of intestinal cytomegalovirus infection in the resistance of ulcerative colitis to steroids and the investigation of cytomegalovirus infection in intestinal biopsies by immunohistochemistry or quantitative polymerase chain reaction assay is strongly recommended. In several studies, treatment of cytomegalovirus infection by ganciclovir was shown to restore the response to immunomodulatory therapies and even to prevent the need for colectomy. All of these recently acquired data need to be validated by randomised clinical trials conducted on a large panel of ulcerative colitis patients.