Low prevalence of CMV infection in patients with Crohn's disease in comparison with ulcerative colitis: effect of different immune response on prevalence of CMV infection

A diagnostic dilemma: cytomegalovirus colitis as an uncommon comorbidity in inflammatory bowel disease: a case report

BACKGROUND

The role of cytomegalovirus infection as an opportunistic pathogen in exacerbating ulcerative colitis and its response to treatment remain a topic of ongoing debate. Clinicians encounter numerous challenges, including the criteria for differentiating between an acute ulcerative colitis flare and true cytomegalovirus colitis, the diagnostic tests for identifying cytomegalovirus colitis, and determining the appropriate timing for initiating antiviral therapy.

CASE PRESENTATION

A 28-year-old Syrian female with a seven-year history of pancolitis presented with worsening bloody diarrhea, abdominal pain, and tenesmus despite ongoing treatment with azathioprine, mesalazine, and prednisolone. She experienced a new flare of acute severe ulcerative colitis despite recently completing two induction doses of infliximab (5 mg/kg) initiated four weeks prior for moderate-to-severe ulcerative colitis. She had no prior surgical history. Her symptoms included watery, bloody diarrhea occurring nine to ten times per day, abdominal pain, and tenesmus. Initial laboratory tests indicated anemia, leukocytosis, elevated C-reactive protein (CRP) and fecal calprotectin levels, and positive CMV IgG. Stool cultures, Clostridium difficile toxin, testing for Escherichia coli and Cryptosporidium, and microscopy for ova and parasites were all negative. Sigmoidoscopy revealed numerous prominent erythematous area with spontaneous bleeding. Biopsies demonstrated CMV inclusions confirmed by immunohistochemistry, although prior biopsies were negative. We tapered prednisolone and azathioprine and initiated ganciclovir at 5 mg/kg for ten days, followed by valganciclovir at 450 mg twice daily for three weeks. After one month, she showed marked improvement, with CRP and fecal calprotectin levels returning to normal. She scored one point on the partial Mayo score. The third induction dose of infliximab was administered on schedule, and azathioprine was resumed.

CONCLUSION

Concurrent cytomegalovirus infection in patients with inflammatory bowel disease presents a significant clinical challenge due to its associated morbidity and mortality. Diagnosing and managing this condition is particularly difficult, especially regarding the initiation or continuation of immunosuppressive therapies.

A case of cytomegalovirus esophagitis difficult to distinguish from Crohn's disease exacerbation

Patients with Crohn's disease are at higher risk of opportunistic infection, especially if treated with immunosuppressive therapy. Cytomegalovirus has been reported to cause ulcerated lesions mainly in the lower gastrointestinal tract of inflammatory bowel disease patients. We herein report a rare case of Crohn's disease complicated with cytomegalovirus esophagitis, which was difficult to distinguish from exacerbation of Crohn's disease. Diagnostic values of clinical course, blood tests, endoscopic and histological examinations are limited but the present case was therapeutically diagnosed by antiviral therapy in combination with histological evidence of cytomegalovirus.

Protective role of flavonoids quercetin and silymarin in the viral-associated inflammatory bowel disease: an updated review

Inflammatory bowel disease (IBD) is a chronic recurrent inflammation of the gastrointestinal tract (GIT). IBD patients are susceptible to various infections such as viral infections due to the long-term consumption of immunosuppressive drugs and biologics. The antiviral and IBD protective traits of flavonoids have not been entirely investigated. This study objective included an overview of the protective role of flavonoids quercetin and silymarin in viral-associated IBD. Several viral agents such as cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV) and enteric viruses can be reactivated and thus develop or exacerbate the IBD conditions or eventually facilitate the disease remission. Flavonoids such as quercetin and silymarin are non-toxic and safe bioactive compounds with remarkable anti-oxidant, anti-inflammatory and anti-viral effects. Mechanisms of anti-inflammatory and antiviral effects of silymarin and quercetin mainly include immune modulation and inhibition of caspase enzymes, viral binding and replication, RNA synthesis, viral proteases and viral assembly. In the nutraceutical sector, natural flavonoids low bioavailability and solubility necessitate the application of delivery systems to enhance their efficacy. This review study provided an updated understanding of the protective role of quercetin and silymarin against viral-associated IBD.

Cytomegalovirus Infection Is Associated With Adverse Outcomes Among Hospitalized Pediatric Patients With Inflammatory Bowel Disease

Background

Adults with inflammatory bowel disease (IBD) are at increased risk of developing cytomegalovirus (CMV) colitis, which is associated with adverse outcomes. Similar studies in pediatric IBD patients are lacking.

Methods

We analyzed non-overlapping years of National Inpatient Sample (NIS) and Kids Inpatient Database (KID) between 2003 and 2016. We included all patients < 21 years with a diagnosis of Crohn's disease (CD) or ulcerative colitis (UC). Patients with coexisting CMV infection during that admission were compared with patients without CMV infection for outcome measures such as in-hospital mortality, disease severity, and healthcare resource utilization.

Results

We analyzed a total of 254,839 IBD-related hospitalizations. The overall prevalence rate of CMV infection was 0.3% with an overall increasing prevalence trend, P < 0.001. Approximately two-thirds of patients with CMV infection had UC, which was associated with almost 3.6 times increased risk of CMV infection (confidence interval (CI): 3.11 to 4.31, P < 0.001). IBD patients with CMV had more comorbid conditions. CMV infection was significantly associated with increased odds of in-hospital mortality (odds ratio (OR): 3.58; CI: 1.85 to 6.93, P < 0.001) and severe IBD (OR: 3.31; CI: 2.54 to 4.32, P < 0.001). CMV-related IBD hospitalizations had increased length of stay by 9 days while incurring almost $65,000 higher hospitalization charges, P < 0.001.

Conclusions

The prevalence of CMV infection is increasing in pediatric IBD patients. CMV infections significantly corelated with increased risk of mortality and severity of IBD leading to prolonged hospital stay and higher hospitalization charges. Further prospective studies are needed to better understand the factors leading to this increasing CMV infection.

The association between antigenemia, histology with immunohistochemistry, and mucosal PCR in the diagnosis of ulcerative colitis with concomitant human cytomegalovirus infection

BACKGROUND

Human cytomegalovirus (HCMV) colitis can be involved in active ulcerative colitis (UC) in patients refractory to steroid and immunosuppressive drugs. Histological examination with colonic biopsy specimens and antigenemia assays are the standard tests for diagnosing HCMV enterocolitis, and we have previously reported the usefulness of mucosal polymerase chain reaction (PCR) methods. However, the associations among histopathological tests, antigenemia assays, and mucosal PCR are unknown.

METHODS

We retrospectively analyzed 82 UC patients who underwent mucosal biopsy from inflamed colonic tissues for histological evaluation and mucosal PCR to detect HCMV. We analyzed the relationships between the HCMV-DNA copy number in colonic mucosa and other HCMV tests.

RESULTS

In total, 131 HCMV mucosal PCR tests from 82 UC patients were positive. The HCMV-DNA copy number was significantly higher in patients with positive immunohistochemistry (IHC) (p < 0.01) and was correlated with the number of positive cells for the antigenemia (C7-HRP, p < 0.01; C10/11, p < 0.01). Receiver operating characteristic curve analysis confirmed 1300 copies/μg of HCMV-DNA as the best diagnostic cut-off value to predict positive results of antigenemia (area under the curve = 0.80, 95% CI 0.68-0.93). HCMV-DNA copy number also correlated with the total UCEIS score (p = 0.013) and the bleeding score (p = 0.014). For each individual patient, a positive correlation between the change in total UCEIS score and HCMV-DNA copy number was observed (p = 0.040).

CONCLUSION

The antigenemia assay and histopathological test with IHC were significantly associated with the HCMV-DNA copy number in colonic tissues. Moreover, endoscopic examination with the UCEIS can help diagnose the HCMV colitis in UC patients.

Current Status of Cytomegalovirus Colitis Among Patients With Inflammatory Bowel Disease in China: A Questionnaire-Based Multicenter Study

BACKGROUND

Cytomegalovirus (CMV) causes infection in patients with inflammatory bowel disease (IBD). This study investigated the prevalence of CMV colitis, the current status of laboratory testing equipment, and physicians' opinions regarding CMV and IBD in China.

METHODS

This retrospective multicenter study was conducted by Chinese members of the Asian Organization for Crohn's and Colitis and included 36 hospitals/institutes divided according to municipality, provincial capital city, and prefectural-level city. A survey questionnaire was administered, and chi-square and Fisher's exact tests were performed.

RESULTS

A total of 4823 inpatients with ulcerative colitis (UC) and 4622 inpatients with Crohn's disease (CD) were included. The percentages of patients with moderate UC in the provincial capital city and municipality were significantly higher than that in the prefectural-level city (38.3% vs 29.1% and 40.1% vs 29.1%, respectively). The percentage of patients with mild CD was significantly lower in the provincial capital city than in the prefectural-level city and municipality (30.4% vs 40.3%; 30.4% vs 39.3%, respectively). There were 3.1% patients with UC and 0.8% patients with CD who had CMV colitis. The prevalence of CMV colitis was lower in patients with CD than in patients with UC (0.8% vs 3.1%). Of the 150 patients with UC and concurrent CMV colitis, 17.3% patients underwent surgery, 2.0% died, and 23.3% experienced complications. Punched-out ulcerations were the major characteristic features for detecting CMV colitis. Approximately 77.8% of hospitals possessed testing facilities capable of conducting CMV immunohistochemistry.

CONCLUSIONS

CMV colitis is an important issue during the disease progression of IBD. However, improvement in knowledge and facilities is required to enhance the prognosis of patients.

Cytomegalovirus Colitis in Immunocompetent and Immunocompromised Children: A 2-Center Study

BACKGROUND

Data about cytomegalovirus (CMV) colitis in children are scarce. We aimed to describe the characteristics of childhood CMV colitis in terms of risk factors, clinical symptoms, diagnosis, therapeutic approaches, and outcomes.

METHODS

Inflammatory bowel disease (IBD) and non-IBD patients with CMV colitis diagnosed by histology and tissue CMV PCR at 2 tertiary centers between January 2017 and November 2019 were studied. Clinical and laboratory data were retrieved from medical records. Underlying conditions, immune status, response to therapy and outcomes were described and followed up to 6 months after diagnosis.

RESULTS

A total of 16 children (8 non-IBD, 7 ulcerative colitis and 1 Crohn's disease) with CMV colitis were included. All patients had persistent diarrhea (bloody in 13 cases). There was a significant age difference between IBD and non-IBD children (P < 0.05). The final diagnosis in 1 patient was immunodeficiency with a mutation in JAK1 gene. Three children were categorized as apparently immunocompromised and 4 children as apparently immunocompetent. Ulcer was not visible in 2 children from the non-IBD group. The mean fecal calprotectin level of IBD children was significantly higher than that of non-IBD children (376.12 ± 231.21 µg/g vs. 160.96 ± 69.94 µg/g, P < 0.05). After follow-up, 1 patient died because of another reason. Ganciclovir was used in 14 of 16 children for 3 weeks and the treatment was continued with valganciclovir in selected 6 children.

CONCLUSIONS

CMV colitis is a rare but overlooked cause of prolonged diarrhea in immunocompetent and immunocompromised children. CMV colitis might present without any ulcer formation at colonoscopy in infants.

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.

Cytomegalovirus reactivation in inflammatory bowel disease: an uncommon occurrence related to corticosteroid dependence

Cytomegalovirus promotes mucosal injury in patients with inflammatory bowel disease, historically affecting 10-25% of ulcerative colitis patients with refractory disease. Viral reactivation is likely related to long-term corticosteroid therapy, which is no longer central to maintenance of patients with inflammatory bowel disease. We hypothesize that viral detection rates have decreased in the modern era, reflecting widespread use of immunomodulatory agents to control inflammation. We performed this study to evaluate the relationships between medical regimens and cytomegalovirus detection rates among patients with inflammatory bowel disease. We searched our database for all patients with established inflammatory bowel disease and severe flares diagnosed from 2002 to 2017. Patients maintained with corticosteroid therapy were considered to be corticosteroid-dependent and those treated with other agents were classified as corticosteroid-independent, provided they had not received corticosteroids within 6 months of colonoscopy. Biopsy samples were reviewed for viral inclusions and subjected to cytomegalovirus immunohistochemistry, and rates of viral detection were compared between groups. There were 135 corticosteroid-dependent patients; most had ulcerative colitis flares occurring during the 2002-2009 period. Patients with ulcerative colitis and Crohn disease were equally represented in the corticosteroid-independent group (n = 133) and most were evaluated for disease flares during the 2010-2017 interval. Cytomegalovirus was detected in 13 (8%) cases; 9 (69%) were diagnosed from 2002 to 2009 and all were obtained from corticosteroid-dependent patients (p = < 0.001). We conclude that rates of cytomegalovirus-related enterocolitis are declining among inflammatory bowel disease patients, reflecting a shift away from corticosteroid-based maintenance therapy in favor of more effective agents that do not promote viral reactivation.

Cytomegalovirus colitis in inflammatory bowel disease and after haematopoietic stem cell transplantation: diagnostic accuracy, predictors, risk factors and disease outcome

BACKGROUND

Concurrent cytomegalovirus (CMV) colitis in inflammatory bowel disease (IBD) and after haematopoietic stem cell transplantation (HSCT) is an important clinical entity associated with high rates of morbidity and mortality.

METHODS

A retrospective study of 47 patients with IBD and 61 HSCT patients was performed regarding the evaluation of diagnostic accuracy of applied methods, predictors, risk factors for CMV disease manifestation, the proportion of patients with antiviral treatment and disease outcome.

RESULTS

The sensitivity of quantitative PCR (qPCR) with a cut-off value of >250 copies/mg for CMV colitis in patients with IBD and HSCT patients was 79% and 92%, respectively. Predictors for CMV colitis in the IBD cohort were anaemia and the presence of endoscopic ulcers. Glucocorticoids, calcineurin inhibitors and >2 concurrent lines of treatment with immunosuppressive drugs could be identified as risk factors for CMV colitis in the IBD cohort with an OR of 7.1 (95% CI 1.7 to 29.9), 21.3 (95% CI 2.4 to 188.7) and 13.4 (95% CI 3.2 to 56.1), respectively. Predictors and risk factors for CMV gastroenteritis in the HSCT cohort was the presence of endoscopic ulcers (OR 18.6, 95% CI 3.3 to 103.7) and >2 concurrent lines of treatment with immunosuppressive drugs. Antiviral therapy was administered in 70% of patients with IBD and 77% of HSCT patients with CMV disease. 71% of antiviral-treated patients with IBD showed an improvement of their disease activity and 14% underwent colectomy. The mortality rate of HSCT patients was 21% irrespective of their CMV status.

CONCLUSIONS

In addition to the implementation of histological methods, qPCR may be performed in patients with suspected high-risk IBD and HSCT patients for CMV colitis. Independent validations of these results in further prospective studies are needed.

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.

Combined Infection of Human Herpes Viruses: A Risk Factor for Subsequent Colectomy in Ulcerative Colitis

BACKGROUND

Little is known about the prevalence and pathogenicity of human herpes viruses except for cytomegalovirus (CMV) in patients with inflammatory bowel disease (IBD). The aim of this study was to determine the prevalence of human herpes viruses on colonic mucosa in patients with IBD and assess the long-term outcomes in these patients.

METHODS

We examined the colonic mucosal specimens from 66 patients with ulcerative colitis (UC), 54 patients with Crohn's disease (CD), and 29 healthy patients to identify the 6 most common types of human herpes virus, using multiplex polymerase chain reaction (PCR) technique.

RESULTS

Herpes simplex virus (HSV)-1/2 and varicella-zoster virus (VZV) were not detected in any of the groups. There was a higher prevalence of Epstein-Barr virus (EBV) (21.2%) and CMV (15.1%) in patients with UC than in patients with CD (EBV 9.3%, CMV 0%) and patents in the healthy control group (EBV 0%, CMV 3.4%). The prevalence of human herpes virus (HHV)-6A/B and HHV-7 was not statistically different among the groups. Five UC patients with inflammation had coexisting CMV and EBV or HHV-6. The combined infection of CMV with EBV or HHV-6 was a significant and independent prognostic factor for subsequent colectomy in patients with UC.

CONCLUSIONS

The increased prevalence of CMV coexisting with EBV/HHV-6 infection was associated with the clinical course in patients with UC. 10.1093/ibd/izy005_video1izy005_Video_15786489376001.

Identification of clinically relevant cytomegalovirus infections in patients with inflammatory bowel disease

Several lines of evidence indicate that cytomegalovirus infection can be substantially associated with onset of inflammatory bowel disease, especially in patients refractory to immunosuppressive treatment. As cytomegalovirus is widely spread in the population, here we present a quantitative detection system suitable to differentiate clinically relevant cytomegalovirus infection from common latent cytomegalovirus. Using a quantitative real-time PCR approach, cytomegalovirus viral load was evaluated in 917 formalin-fixed and paraffin-embedded colon biopsy samples of 136 patients diagnosed with inflammatory bowel disease. Besides initial cytomegalovirus testing, the PCR system was also used to monitor therapy response after antiviral treatment. Cytomegalovirus DNA was detected in 37 patients (27%) with varying viral loads ranging from 5 to 8.7 × 10⁵ copies/10⁵ cells. Thereof, 13 patients (35%) received an antiviral treatment with 12 of them going into remission (92%). Later, five patients displayed a relapse and three patients who agreed to restart antiviral treatment again showed positive therapy response. A retrospective comparison of viral loads with antiviral therapy response revealed a threshold of 600 cytomegalovirus copies/10⁵ cells as indicative for clinically relevant infection. Of note, sensitivity of cytomegalovirus detection by immunohistochemistry was found to be insufficient to reliably identify antiviral therapy responders. In conclusion, quantitative real-time PCR using formalin-fixed biopsy samples is suitable for detection of cytomegalovirus infection in tissue samples of patients with inflammatory bowel disease. Moreover, it allows the definition of a viral load threshold, predictive for clinical relevance concerning antiviral therapy response.

Impact of Infliximab and Cyclosporine on the Risk of Colectomy in Hospitalized Patients with Ulcerative Colitis Complicated by Cytomegalovirus-A Multicenter Retrospective Study

BACKGROUND

Cytomegalovirus (CMV) is frequently detected in patients with ulcerative colitis (UC). The impact of CMV infection on the outcome of UC exacerbation remains unclear. The benefit of combining antiviral with anti-inflammatory treatment has not been evaluated yet. The aim of this study was to compare the outcome of CMV-positive hospitalized patients with UC treated with antiviral therapy either alone or combined with salvage anti-inflammatory therapy (infliximab [IFX] or cyclosporine A [CsA]).

METHODS

This was a multicenter retrospective study of hospitalized CMV-positive patients with UC. The patients were classified into 2 groups: antiviral-if treated with antivirals alone; combined-if treated with both antiviral and anti-inflammatory therapy. The outcomes included the rate of colectomy in both arms during the course of hospitalization and after 3/12 months.

RESULTS

A total of 110 patients were included; 47 (42.7%) patients did not receive IFX nor CsA; 36 (32.7%) received IFX during hospitalization or within 1 month before hospitalization; 20 (18.1%) patients received CsA during hospitalization; 7 (6.4%) were exposed to both IFX and CsA. The rate of colectomy was 14.5% at 30 days, 20.0% at 3 months, and 34.8% at 12 months. Colectomy rates were similar across treatment groups. No clinical and demographic variables were independently associated with the risk of colectomy.

CONCLUSIONS

IFX or cyclosporine therapy is not associated with additional risk for colectomy over antiviral therapy alone in hospitalized CMV-positive patients with UC.

Approach to cytomegalovirus infections in patients with ulcerative colitis

Cytomegalovirus (CMV) reactivation is common in patients with severe ulcerative colitis (UC), and may ref lect exacerbation of mucosal inf lammation and/or administration of immunosuppressants. The question of whether CMV is an active pathogen or 'an innocent bystander' in the exacerbation of UC remains controversial. Patients with UC exacerbated by reactivated CMV experience worse prognoses than those without CMV reactivation and antiviral therapy significantly reduces the need for colectomy in patients with severe UC and high-grade CMV infection, indicating that CMV plays a role in UC prognosis. Therefore, the CMV status of patients on immunosuppressants, particularly those with steroid-refractory or -dependent UC, should be tested. When CMV is detected, be performed based on should adequate treatment the extent of the viral load and the presence of certain clinical features including a large ulcer. Anti-tumor necrosis factor agents may be useful for treating CMV colitis complicating UC.

PCR detection of human herpesviruses in colonic mucosa of individuals with inflammatory bowel disease: Comparison with individuals with immunocompetency and HIV infection

BACKGROUND

Detection of human herpesviruses (HHVs) other than cytomegalovirus (CMV) in colonic mucosa of individuals with inflammatory bowel disease (IBD) remains unknown. This study identified eight HHVs in the colonic mucosa of individuals with IBD and compared the results with immunocompetent and human immunodeficiency virus (HIV)-infected individuals.

METHODS

A total of 89 individuals who had colorectal ulcer on colonoscopy were enrolled: 26 with immunocompetency (n = 26), 41 with IBD, and 22 with HIV infection. We examined the colonic ulcers for the presence of eight HHVs-herpes simplex virus (HSV)-1/2, varicella zoster virus (VZV), CMV, Epstein-Barr virus (EBV), HHV-6, HHV-7, and HHV-8-using mucosal PCR.

RESULTS

The IBD group had positivity rates of 0%, 0%, 0%, 53.7%, 24.4%, 39%, 39%, and 0% for HSV-1, HSV-2, VZV, EBV, CMV, HHV-6, HHV-7, and HHV-8, respectively. The positivity rates of EBV and CMV in colonic mucosa increased significantly in the order of the immunocompetent, IBD, and HIV groups (EBV: 23.1%, 53.7%, 72.7%, P for trend = 0.0005; CMV, 7.7%, 24.4%, 54.5%, P for trend = 0.0003, respectively), but no increase was found in the other HHVs. Median mucosal EBV DNA values in the immunocompetent, IBD, and HIV groups were 0, 76, and 287 copies/μg DNA, respectively (P for trend = 0.002). Corresponding median mucosal CMV DNA values were 0, 0, and 17 copies/μg DNA (P for trend = 0.0001). There was no significant difference in the positivity rates of the eight HHVs between ulcerative colitis and Crohn's disease.

CONCLUSION

The HHVs of EBV, CMV, HHV-6, and HHV-7, but not of HSV-1, HSV-2, VZV, or HHV-8, were identified in the colonic mucosa of IBD individuals. EBV and CMV in colonic mucosa was correlated with host immune status in increasing order of immunocompetent, IBD, and HIV-infected individuals.

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.

Cytomegalovirus disease in inflammatory bowel disease: epidemiology and disease characteristics in a large single-centre experience

BACKGROUND

Patients with inflammatory bowel disease (IBD) show an increased risk of developing cytomegalovirus (CMV) disease because of immunosuppressive medication and malnutrition. Here, we aimed to investigate the prevalence and clinical characteristics of CMV disease in our cohort of IBD patients.

PATIENTS AND METHODS

We carried out a retrospective analysis of 1023 IBD patients treated at our IBD clinic at the University Hospital Zurich between 2007 and 2014. CMV disease was defined as a positive immunohistochemistry for CMV and 14 patients were identified.

RESULTS

The prevalence of CMV disease in our IBD cohort was 1.37%. Twelve patients had ulcerative colitis and two had Crohn's disease with colonic involvement. All patients who developed CMV disease received immunosuppressive medication or, as in one case, had HIV infection. The most used immunosuppressive medications were steroids and azathioprine. The most common therapeutic strategy was the consecutive use of ganciclovir and valganciclovir. Ten patients recovered and two were treatment refractory; among these, one required colectomy and two had a relapse.

CONCLUSION

CMV disease may influence the clinical course of IBD. There is probably an association between CMV disease and IBD-specific medication. Risk factors, epidemiology and therapeutic strategy need to be further investigated.

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.

Clinical features of opportunistic infections in ulcerative colitis patients

AIM: To explore the clinical features of opportunistic infections and the underlying risk factors of cytomegalovirus (CMV) infection in ulcerative colitis (UC) patients.

METHODS: We enrolled 87 ulcerative colitis patients treated at our hospital from March 2004 to April 2015. Data concerning clinical manifestations, endoscopic characteristics, pathological changes as well as laboratory findings were collected and analyzed. We further divided the patients into a CMV positive and a CMV negative group to explore the possible risk factors for CMV infection.

RESULTS: Among 87 patients, there were 12 CMV positive patients, 5 Clostridium difficile positive patients, three oral Candida positive patients, and two Pneumocystis carinii positive patients. Independent risk factors for CMV infection in UC patients included low leukocyte count, pan-colitis, and use of corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs) as well as antibiotics during recent 2 mo, while the use of proton pump inhibitors (PPIs) had no significant impact on CMV infection.

CONCLUSION: UC patients tend to develop opportunistic infections, such as CMV, Clostridium difficile, oral Candida and Pneumocystis carinii infections. Low leukocyte count, pan-colitis, use of corticosteroids, NSAIDs as well as antibiotics during recent 2 mo are risk factors for CMV infection in UC patients.

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.

Diagnosing cytomegalovirus in patients with inflammatory bowel disease--by immunohistochemistry or polymerase chain reaction?

Cytomegalovirus (CMV) reactivation is a common complication in patients with inflammatory bowel diseases (IBD), particularly in those with steroid-resistant ulcerative colitis. It is usually diagnosed by histopathologic and immunohistochemical examination of the colon biopsy. The introduction of quantitative, real-time polymerase chain reaction (qPCR) has been recommended to improve the sensitivity, but there is little consensus on how to use it. We compared the two methods in samples from resected bowel of patients with IBD. Twelve patients with IBD who had undergone bowel resection were analysed for CMV, using qPCR and immunohistochemistry. In all cases, tissue samples from the base and the edge of ulcers and from uninvolved mucosa were obtained. The highest densities of CMV-positive cells were found in samples from the base of ulcers (immunohistochemistry 0-0.47 positive cells/mm(2); qPCR 10-3809 viral copies/mg) or the edge of ulcers (immunohistochemistry 0.06-0.32 positive cells/mm(2); qPCR 35-1049 viral copies/mg). In samples of uninvolved mucosa, immunohistochemistry was negative, whereas qPCR was either negative or showed very low values (0-3 viral copies/mg). We conclude that both immunohistochemistry and qPCR can be successfully used for diagnosing CMV reactivation in patients with IBD. The base and the edge of ulcers are the optimal sites for endoscopic biopsies. The density of CMV-positive cells was low and their distribution within the colon uneven. It therefore seems that the number of sampled biopsies and/or the number of investigated levels is more important that the choice of diagnostic method.

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.

Review article: cytomegalovirus and inflammatory bowel disease

BACKGROUND

The association between ulcerative colitis and cytomegalovirus (CMV) has been recognised for over 50 years; and the role of CMV in ulcerative colitis in general, and steroid resistance in particular, remains a topic of ongoing controversy. The outcome for patients with CMV reactivation appears worse than that for patients without reactivation, but it is not entirely clear whether CMV is a contributor or a bystander and if treatment with anti-virals alters the course of inflammatory bowel disease (IBD).

AIM

To review the role of CMV associated with IBD, including epidemiology, clinical features, diagnosis and management strategies.

METHODS

By reviewing literature available on CMV associated with IBD in adult patients. A PubMed literature search was performed using the following terms individually or in combination: CMV colitis, cytomegalovirus colitis, IBD and CMV, CMV treatment.

RESULTS

Cytomegalovirus reactivation is common in patients with severe colitis, with a reported prevalence of 4.5-16.6%, and as high as 25% in patients requiring colectomy for severe colitis. The outcome for this group of patients appears worse than that for patients without reactivation; however, reported remission rates following treatment with anti-viral therapy are as high as 71-86%.

CONCLUSIONS

Evidence, although not conclusive, supports testing for CMV colonic disease in cases of moderate to severe colitis, by processing biopsies for haematoxylin and eosin staining with immunohistochemistry and/or, CMV DNA real-time polymerase chain reaction; and if present treating with ganciclovir.

A model for identifying cytomegalovirus in patients with inflammatory bowel disease

BACKGROUND & AIMS

The presentation of cytomegalovirus (CMV) disease in patients with inflammatory bowel disease (IBD) can be similar to that of idiopathic IBD. It is a challenge to identify patients at highest risk for CMV. We investigated risk factors and generated a clinical score to identify patients with IBD at highest risk for CMV disease.

METHODS

We performed a retrospective case-control study of 68 patients with IBD (66% with ulcerative colitis, 31% with Crohn's disease, and 3% with unclassified IBD) diagnosed with CMV disease on the basis of tissue analysis from January 2005 through December 2011 at Mayo Clinic, Rochester. The patients were each matched with 3 patients with IBD and suspected CMV disease (controls). An a priori set of the most objective variables was used to create a model to identify those with CMV disease. Scores were assigned to each significant factor from the multivariable analysis. Cutoff values that identified patients with CMV with ≥85% sensitivity and specificity were selected.

RESULTS

Patients with medically refractory IBD (odds ratio [OR], 3.69; P < .001) or endoscopic ulcers (OR, 3.06; P < .001) and those treated with corticosteroids (OR, 2.95; P < .001) or immunomodulators (OR, 1.86; P = .030) but not tumor necrosis factor antagonists (OR, 1.30; P = .376) were more likely to have CMV disease than patients with IBD without these features. In a multivariable model, refractory disease, treatment with immunomodulators, and age older than 30 years were independently associated with CMV disease. Use of tumor necrosis factor antagonists was an insignificant factor even after adjustment.

CONCLUSIONS

Clinical features can identify patients with IBD at risk for CMV disease. This model may help clinicians stratify patients on the basis of risk when CMV disease is suspected.

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 treatment of ulcerative colitis with cytomegalovirus infection: importance of controlling mucosal inflammation to prevent cytomegalovirus reactivation

Human cytomegalovirus (HCMV) is a member of the herpesvirus family. HCMV infection persists throughout the host lifespan in a latent state following primary infection. The ability of HCMV to escape control by the host immune system and its resulting reactivation suggests the importance of ongoing immune surveillance in the prevention of HCMV reactivation. HCMV is a common cause of opportunistic infection that causes severe and fatal disease in immune-compromised individuals. In inflammatory bowel disease patients, particularly those with ulcerative colitis (UC), HCMV is often reactivated because these patients are frequently treated with immunosuppressive agents. This reactivation exacerbates colitis. Additionally, HCMV infection can induce severe colitis, even in patients with UC who have never been treated with immunosuppressive agents. However, the role of HCMV in colonic inflammation in patients with UC remains unclear. Here, we present previous and current clinical data on the diagnosis and treatment of HCMV infection in UC. Additionally, our experimental data from a newly established mouse model mimicking UC with concomitant CMV infection clearly demonstrate that inflammation could result in the exacerbation of UC disease activity with induction of HCMV reactivation. In summary, optimal control of colonic inflammation should be achieved in UC patients who are refractory to conventional immunosuppressive therapies and are positive for HCMV.

Establishment of a novel mouse model of ulcerative colitis with concomitant cytomegalovirus infection: in vivo identification of cytomegalovirus persistent infected cells

BACKGROUND

Human cytomegalovirus (HCMV) infection is considered to be an exacerbating factor in patients with ulcerative colitis (UC). However, the pathogenicity of HCMV in the exacerbation of UC remains unclear. The lack of a model mimicking UC with HCMV infection has posed a challenge for research into the pathogenic mechanism of HCMV in flare of UC. Therefore, the aim of our study was to establish a new mouse model of UC with HCMV infection.

METHODS

We established latent murine CMV (MCMV) infection in T-cell receptor α knockout (TCR-α KO) mice at an early age by adjustment of viral dose. Next, we performed immunohistochemical analysis in various organs of infected adult TCR-α KO mice to prove the correlation between MCMV infection and development of colitis. We then assessed colitis histologically and cytokine expression in the colon of infected and uninfected TCR-α KO mice. Finally, the types of MCMV-infected cells in the inflamed colon were examined by immunohistochemical analysis.

RESULTS

MCMV antigen-positive cells reappeared predominantly in the inflamed colon of TCR-α KO mice. Severe colitis developed in the infected TCR-α KO mice compared with uninfected mice, and Th1/Th17 and Th2 responses were strongly induced. MCMV-infected cells were mainly perivascular stromal cells including pericytes, expressing platelet-derived growth factor receptor-beta (PDGFR-β) and CXC chemokine ligand 12 (CXCL12).

CONCLUSIONS

In this study, we established, to our knowledge, the first mouse model of UC with HCMV infection. This model is an excellent tool for clarifying the detailed pathogenicity of HCMV in the exacerbation of UC and developing new treatment strategy for active UC with HCMV infection.

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.

Human herpesvirus 6 and cytomegalovirus in ileocolonic mucosa in inflammatory bowel disease

OBJECTIVES

Reactivation of a latent cytomegalovirus (CMV) may occur in inflammatory bowel disease (IBD). Data of human herpesvirus 6 (HHV-6)--a close relative to CMV--in active IBD are scarce. The aim of this study was to detect HHV-6 and CMV antigens in the mucosa of active and inactive IBD.

MATERIAL AND METHODS

79 IBD patients (47 ulcerative colitis (UC) and 32 Crohn's disease (CD)) were recruited and endoscopic and histological disease activity was scored. Control group consisted of 15 non-IBD patients with normal colonoscopy. Immunohistochemical stainings for HHV-6B and CMV antigens were performed on biopsy specimens from the ileum and colorectum. The intensity of HHV-6B and CMV expression was graded as negative, mild, moderate, or intense.

RESULTS

HHV-6B antigen was positive in 35 (44%) and CMV in 64 (81%). Of controls, 6 (40%) were mildly positive for HHV-6 and 6 (40%) for CMV. In IBD, both CMV and HHV-6B intensity correlated with endoscopic disease severity (CMV p = 0.010 and HHV-6 p = 0.048). Simultaneous HHV-6B and CMV antigen expression occurred in 29 (37%) and associated with endoscopic activity (p = 0.006) and to a number of immunosuppressives (p = 0.033). A significant difference in HHV-6B positivity was found between endoscopically active and inactive UC (p = 0.040). Both CMV and HHV-6B intensity correlated with histological severity in the rectal biopsy specimens (for CMV p = 0.040 and for HHV-6B p = 0.027).

CONCLUSIONS

Both viruses occurred ubiquitously in the IBD mucosa. Coexistence of viruses was common and associated with disease activity and use of immunosuppressives. HHV-6B intensity correlated with endoscopic severity in UC.