Inflammatory bowel disease exacerbation associated with Epstein-Barr virus infection

The role of Epstein-Barr virus in autoimmune and autoinflammatory diseases

Epstein-Barr Virus (EBV), a dsDNA herpesvirus, is believed to play a significant role in exacerbating and potentially triggering autoimmune and autoinflammatory maladies. Around 90% of the world is infected with the virus, which establishes latency within lymphocytes. EBV is also known to cause infectious mononucleosis, a self-limited flu-like illness, in adolescents. EBV is often reactivated and it employs several mechanisms of evading the host immune system. It has also been implicated in inducing host immune dysfunction potentially resulting in exacerbation or triggering of inflammatory processes. EBV has therefore been linked to a number of autoimmune diseases, including systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, and Sjögren's syndrome. The review examines the molecular mechanisms through which the virus alters host immune system components thus possibly resulting in autoimmune processes. Understanding the mechanisms underpinning EBV-associated autoimmunity is pivotal; however, the precise causal pathways remain elusive. Research on therapeutic agents and vaccines for EBV has been stagnant for a long number of years until recent advances shed light on potential therapeutic targets. The implications of EBV in autoimmunity underscore the importance of developing targeted therapeutic strategies and, potentially, vaccines to mitigate the autoimmune burden associated with this ubiquitous virus.

Positive correlation between latent Epstein-Barr virus infection and severity of illness in inflammatory bowel disease patients

BACKGROUND

Emerging studies indicate the critical involvement of microorganisms, such as Epstein-Barr virus (EBV), in the pathogenesis of inflammatory bowel disease (IBD). Immunosuppressive therapies for IBD can reactivate latent EBV, complicating the clinical course of IBD. Moreover, the clinical significance of EBV expression in B lymphocytes derived from IBD patients’ intestinal tissues has not been explored in detail.

AIM

To explore the clinical significance of latent EBV infection in IBD patients.

METHODS

Latent EBV infection was determined by double staining for EBV encoded RNA and CD20 in colon specimens of 43 IBD patients who underwent bowel resection. Based on the staining results, the patients were divided into two groups, according to their latent EBV infection states - negative (n = 33) and positive (n = 10). Illness severity of IBD were assigned according to Crohn’s disease activity index (ulcerative colitis) and Mayo staging system (Crohn’s disease). The clinic-pathological data were analyzed between the two different latent EBV groups and also between the mild-to-moderate and severe disease groups.

RESULTS

Systolic pressure (P = 0.005), variety of disease (P = 0.005), the severity of illness (P = 0.002), and pre-op corticosteroids (P = 0.025) were significantly different between the EBV-negative and EBV-positive groups. Systolic pressure (P = 0.001), variety of disease (P = 0.000), pre-op corticosteroids (P = 0.011) and EBV infection (P = 0.003) were significantly different between the mild-to-moderate and severe disease groups.

CONCLUSION

IBD patients with latent EBV infection may manifest more severe illnesses. It is suggested that the role of EBV in IBD development should be further investigated, latent EBV infection in patients with serious IBD should be closely monitored, and therapeutic course should be optimized.

Impact of Epstein-Barr virus infection in patients with inflammatory bowel disease

A high prevalence of Epstein-Barr virus (EBV) infection in patients with inflammatory bowel disease (IBD) has been reported in many case reports and studies; thus, the association between EBV and IBD has gained increasing attention. Patients with IBD are at an increased risk of opportunistic EBV infection owing to the common use of immunomodulators. EBV infection in IBD patients can cause various complications, including superimposed viral colitis, which is associated with chronicity, exacerbation, and poor prognosis of refractory IBD, and can induce progression to lymphoproliferative disorders, such as EBV-positive mucocutaneous ulcer (EBVMCU), lymphomatoid granulomatosis (LYG), hemophagocytic lymphohistiocytosis (HLH) and diffuse large B-cell lymphoma (DLBCL). It has been suggested to screen for EBV before initiating immunosuppressive therapy and monitor the status of EBV infection in patients with IBD, especially those who are EBV-seronegative and have a risk of primary EBV infection. Clinicians should also be careful of misdiagnosing IBD and EBV-associated lymphoproliferative diseases due to similarities in both clinical symptoms and endoscopic manifestations. Withdrawal of immunosuppressants has been shown to be an effective strategy to achieve remission of disease at the time of EBV diagnosis, but antiviral therapy remains controversial. The present review aims to describe the characteristics of the complications caused by EBV infection and generalize the recent research progress on and challenges caused by EBV infection in IBD patients. The literature for writing this review was collected from 'PubMed' research engine. The keywords 'inflammatory bowel disease and Epstein-Barr virus' or 'ulcerative colitis and Epstein-Barr virus' or 'Crohn's disease and Epstein-Barr virus' were used to collect the literature and relevant papers were collected to help writing this review.

Chronic active Epstein-Barr virus enteritis: A literature review

Chronic active Epstein-Barr virus (CAEBV) enteritis is a rare disease that has not been well described. Owing to the similarities between CAEBV enteritis and inflammatory bowel diseases such as ulcerative colitis and Crohn's disease, it is easy to be misdiagnosed and mistreated in clinical practice, resulted in complications and even death in severe cases. Through a literature review, this study aimed to summarize the clinical characteristics, pathological features, examinations, and treatment strategies of CAEBV enteritis and its similarities and differences with inflammatory bowel diseases.

SERO-PREVALENCE OF EPSTEIN-BARR VIRUS IN IRAQI INFLAMMATORY BOWEL DISEASE

OBJECTIVE

The aim: Determine the frequency of anti-viral capsid antigen IgM, IgG and IgA in inflammatory bowel disease.

PATIENTS AND METHODS

Materials and methods: Case controlled study conducted during involved 60 Crohn's disease, 60 ulcerative colitis and 60 subjects as a control group with negative gastroin¬testinal symptoms. Diagnosis and disease classification were established according to Montreal disease classification of inflammatory bowel diseases. Measurement of serum anti-VCA IgM, IgG and IgA was done, using ELISA method.

RESULTS

Results: The current results showed a higher frequency of EBV seropositivity among both Crohn's disease and ulcerative colitis 96.67% in comparison with controls 78.33. None statistical significance observed according to sex of patients. IgM were significantly associated with younger than 16 years 33.33%. IgA anti-VCA were significantly frequent within 17-40 years old comprising 100%. Patients with colonic and ileocolonic site of lesions were significantly have frequent anti-VCA IgA 96.43% and 96%. In ulcerative colitis IgM subtype of anti-VCA 35.71% frequent in extensive colitis. Anti-VCA IgG were statistically significant with moderate and severe ulcerative colitis cases 100%. Also, anti-VCA IgA associated with severity of ulcerative colitis 100% of mild cases, 96.43% of moderate cases and 100% of severe cases.

CONCLUSION

Conclusion: EBV seropositivity were detected among IBD cases, however viral infection might be associated with distinct and severe cases that requires anti-viral therapy.

Epstein-Barr virus nuclear antigen 2 extensively rewires the human chromatin landscape at autoimmune risk loci

The interplay between environmental and genetic factors plays a key role in the development of many autoimmune diseases. In particular, the Epstein-Barr virus (EBV) is an established contributor to multiple sclerosis, lupus, and other disorders. Previously, we showed that the EBV nuclear antigen 2 (EBNA2) transactivating protein occupies up to half of the risk loci for a set of seven autoimmune disorders. To further examine the mechanistic roles played by EBNA2 at these loci on a genome-wide scale, we globally examined gene expression, chromatin accessibility, chromatin looping, and EBNA2 binding in a B cell line that was (1) uninfected, (2) infected with a strain of EBV lacking EBNA2, or (3) infected with a strain that expresses EBNA2. We identified more than 400 EBNA2-dependent differentially expressed human genes and more than 5000 EBNA2 binding events in the human genome. ATAC-seq analysis revealed more than 2000 regions in the human genome with EBNA2-dependent chromatin accessibility, and HiChIP data revealed more than 1700 regions where EBNA2 altered chromatin looping interactions. Autoimmune genetic risk loci were highly enriched at the sites of these EBNA2-dependent chromatin-altering events. We present examples of autoimmune risk genotype-dependent EBNA2 events, nominating genetic risk mechanisms for autoimmune risk loci such as ZMIZ1 Taken together, our results reveal important interactions between host genetic variation and EBNA2-driven disease mechanisms. Further, our study highlights a critical role for EBNA2 in rewiring human gene regulatory programs through rearrangement of the chromatin landscape and nominates these interactions as components of genetic mechanisms that influence the risk of multiple autoimmune diseases.

Impact of Epstein-Barr virus infection on inflammatory bowel disease (IBD) clinical outcomes

OBJECTIVE

To evaluate the role of Epstein-Barr virus (EBV) on the intestinal mucosa in the evolution of inflammatory bowel disease (IBD), to investigate the risk factors for EBV infection and the frequency of EBV-associated lymphoproliferative disorders in IBD patients.

METHODS

Intestinal biopsies of IBD patients with available EBV status determined by Epstein-Barr-encoding RNA (EBER) in situ hybridization were searched in the Pathology Database of our center. Clinical information, including phenotypic characteristics of IBD, previous treatments, diagnosis of lymphoma, and patient outcome, were reviewed for all cases.

RESULTS

56 patients with IBD (28 Crohn´s disease, 27 ulcerative colitis and one unclassified colitis) were included. EBV in intestinal mucosa was positive in 26 patients (46%), in one case associated to a lymphoproliferative syndrome. EBV positivity was associated with severe histological activity (52% vs. 17.2%; p 0.007), presence of a lymphoplasmacytic infiltrate (50% vs. 33.3%; p 0.03) and active steroid treatment (61.5% vs. 33.3%; p 0.03). Multivariate analyses only found association between EBV and lymphoplasmacytosis (p 0.001). Escalation in previous treatment was significantly more frequent in the EBER+ group (53.8% vs. 26.7%; p 0.038). No cases developed lymphoma in the follow-up.

CONCLUSIONS

EBV on the intestinal mucosa is associated with a poor outcome of IBD and the need for escalation in therapy. Lymphoplasmacytic infiltrate is associated with EBV infection. EBER+ patients used steroids more frequently compared with EBER- patients. No EBER+ patients developed a lymphoma during follow-up.

Human Cytomegalovirus and Epstein-Barr virus specific immunity in patients with ulcerative colitis

Human Cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) are endowed with the ability of establishing lifelong latency in human hosts and reactivating in immunocompromised subjects, including patients suffering from ulcerative colitis (UC). We, therefore, aimed to investigate virus-specific immunity in UC patients. A cohort of 24 UC patients (14 responders and 10 refractory to therapy) and 26 control subjects was prospectively enrolled to undergo virus-specific serology (by ELISA assay) and assessment of both CD4⁺ and CD8⁺ virus-specific T-cell response (by interferon-γ enzyme-linked immunospotanalysis). In parallel, mucosal viral load was determined by quantitative real-time PCR and the values were correlated with both clinical and endoscopic indexes of activity. For statistics, the t-test, Mann-Withney test, Fisher's exact test and Spearman rank correlation test were applied; p < 0.05 was considered significant. EBV-specific CD4⁺ and CD8⁺ T-cell responses were significantly lower in UC patients compared to controls (p < 0.0001 and p = 0.0006, respectively), whereas no difference was found for HCMV-specific T-cell response. When dividing the UC group according to response to therapy, both responders and refractory UC patients showed a deficient EBV-specific CD4⁺ T-cell response with respect to controls (p < 0.04 and p = 0.0003, respectively). Moreover, both EBV and HCMV mucosal loads were significantly higher in refractory UC than in responders and controls (p = 0.007 and 0.003; and p = 0.02 and 0.001, respectively), and correlated with activity indexes. Steroid therapy seemed the main risk factor for triggering EBV colitis. Finally, no cases of IgM positivity were found in the study population. An impaired EBV-specific immunity was clearly evident in UC patients, mostly in those refractory to therapy. The ELISPOT assay may serve as new tool for quantifying and monitoring virus-specific T-cell immunity in UC.

Substantial Epstein-Barr virus reactivation in a case of severe refractory ulcerative colitis: a possible role in exacerbation

Ulcerative colitis (UC) is an inflammatory bowel disease that causes chronic inflammation in the colon. 5-aminosalicylic acid and immunosuppressive medications such as corticosteroids, immunomodulators, and biologic agents are used to treat these patients. However, patients with UC who receive immunosuppressive medications may be at risk for certain opportunistic infections. Epstein-Barr virus (EBV) is one of those opportunistic infections, and its pathogenic role has been implicated in refractory UC, but its pathogenicity should be further investigated. Here, we report a surgical case of refractory UC that demonstrated a serologically post-infected pattern of EBV at admission but that later had a high load of EBV in both the peripheral blood and colonic mucosa. These findings suggest that EBV may have been reactivated in the colon, after which it damaged the colonic mucosa and aggravated inflammation in this patient with UC. Thus, EBV might lead to severity and a refractory response against corticosteroids and anti-TNFα agents, necessitating emergency surgery. Viral surveillance for EBV in patients with refractory UC may facilitate understanding of the patient's pathophysiology and predicting response to medications, and the development of antiviral intervention for those patients may improve their prognosis.

Clinical features of Epstein-Barr virus in the intestinal mucosa and blood of patients with inflammatory bowel disease

BACKGROUND

The role of Epstein-Barr virus (EBV) in inflammatory bowel disease (IBD) remains to be elucidated. The aim of this study was to investigate the presence of EBV in the blood and intestinal mucosa of patients with IBD and evaluate the association between EBV positivity and IBD.

METHODS

Patients with IBD, hospitalized between January 2015 and April 2018, were enrolled. The EBV-DNA load in blood samples from each subject was analyzed by quantitative real-time polymerase chain reaction. EBV-encoded small-RNA 1 (EBER-1) was detected by in-situ hybridization in intestinal mucosa tissue sections of patients with IBD.

RESULT

EBV-DNA was detected in 48 out of 568 patients with IBD (8.4%), and EBER-1 positivity was detected in 27 of these patients (56.3%). Refractory IBD and severe mucosal inflammation were more common in patients with detectable levels of EBER-1 than in those without; the number of EBER-1-positive cells positively correlated with mucosal inflammation (P value < 0.05). Age (≥60 years old) and use of azathioprine were risk factors for EBV infection. There was no significant difference in clinical remission rate and surgical rate between the EBER-1 positive group and EBER-1 negative group, antiviral group and the non-antiviral group, among IBD patients who tested positive for EBV-DNA.

CONCLUSION

Elderly patients with IBD, treated with azathioprine, are more susceptible to EBV positivity. Further, EBV mucosal detection correlated with the severity of mucosal damage and refractoriness, but not prognosis.

A review on co-existent Epstein-Barr virus-induced complications in inflammatory bowel disease

There have been growing reports regarding the presence of Epstein-Barr virus (EBV) in the intestine portions of patients suffering from ulcerative colitis and Crohn's disease, collectively termed as inflammatory bowel disease (IBD). Indeed, the prevalence of EBV infection increases in IBD patients due to prolonged employment of immunosuppressive drugs including azathioprine and infliximab. In turn, coinfection with EBV increases the propensity of development of lymphoproliferative disorders in the gastrointestinal tract including Hodgkin lymphoma, non-Hodgkin lymphomas, and lymphoepithelioma-like cholangiocarcinoma. Therefore, it is recommended that IBD patients on prolonged immunomodulator therapy should be monitored for the presence of primary intestinal lymphoproliferative diseases. Moreover, coinfection of EBV complicates the clinical course of IBD by increasing the severity, chronicity, inducing refractoriness and increasing relapse incidences. Therefore, it is recommended that antiviral drugs should be added in the conventional IBD therapy in the suspected cases of EBV infection. Research has also revealed that EBV-induced colitis is very similar to IBD and there are chances of misdiagnosis of IBD in the presence of EBV colitis. The proper diagnosis of EBV infection along with its timely treatment is necessary to avoid the severe complications in patients of IBD. The present review discusses the role of EBV coinfection in increasing the clinical complications of IBD patients.

Refractory inflammatory bowel disease: is there a role for Epstein-Barr virus? A case-controlled study using highly sensitive Epstein-Barr virus-encoded small RNA1 in situ hybridization

A potential role for viral infections has been implicated in inflammatory bowel disease (IBD) unresponsive to medical treatment. It is well known that Epstein-Barr virus (EBV) infection can elicit a brisk mononuclear response in the gastrointestinal tract. The aim of this study was to further evaluate the role of EBV in patients with refractory IBD and compare them with nonrefractory IBD cases. Surgically resected colonic specimens from 67 patients with refractory IBD (62 with ulcerative colitis, 3 patients with Crohn disease, and 2 patients with indeterminate colitis) were retrieved. Twelve colectomy specimens from patients with ulcerative colitis who had undergone resections for dysplasia or endometriosis were included as controls. Highly sensitive EBV-encoded small RNA1 (EBER-1) in situ hybridization was performed on a representative block from each specimen. EBER-1 reactivity was graded as absent, focal, or diffuse. EBV was detected in 60% (40/67) of patients with refractory IBD compared with 25% (3/12) of the control group (P < .05). Focal EBER-1 positivity was present in 45% of cases of refractory IBD compared with 25% of controls. Diffuse EBER-1 reactivity was seen in 15% of cases of refractory IBD (10/67); none of the samples from the control group contained diffuse EBER-1 positivity. There was a positive correlation between EBER positivity and depth of inflammation and mucosal ulceration in patients with refractory IBD. Our findings suggest a potential role for EBV infection in patients with refractory IBD.

vhfRNAi: a web-platform for analysis of host genes involved in viral infections discovered by genome wide RNAi screens

Knockdown of host genes using high-throughput genome-wide RNA interference screens has identified numerous host factors that affect viral infections, which would be helpful in understanding host-virus interactions. We have developed a vhfRNAi web resource based on genome-wide RNAi experiments for viruses. It contains experimental details of 12 249 entries (host factors + restriction factors) for 18 viruses. Simultaneously, this resource encompasses analysis of overlapping genes, genome wide association studies, gene ontology (GO), pathogen interacting proteins, interaction networks and pathway enrichment. Using overlap analysis, it was found that Influenza A virus shared overlapping host genes with the majority of viruses including Hepatitis C virus and Dengue virus 2. In the genome wide association studies analysis, 429 diseases/traits were mapped, of which obesity-related traits were the most common. GO analysis revealed that the major categories belonged to metabolic processes, molecule transport, signal transduction, proteolysis, etc. In the pathogen interacting protein analysis, protein interaction data from different resources can be explored for further understanding of host-virus biology. By pathway enrichment analysis, a total of 8955 genes were mapped on 303 pathways with most of the hits coming from metabolic pathways. We have found 491 genes that are not essential for the host but essential for the virus and can be targeted to inhibit the virus. These may be explored as potential candidates for drug targets. The resource is freely accessible at and will be useful in understanding host-virus biology as well as identification of targets for the development of antiviral therapeutics.

Differential cellular localization of Epstein-Barr virus and human cytomegalovirus in the colonic mucosa of patients with active or quiescent inflammatory bowel disease

The role of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in the exacerbation of inflammatory bowel disease (IBD) is still uncertain. We prospectively investigated the presence of EBV and HCMV infection in both epithelial and immune cells of colonic mucosa of IBD patients, both refractory and responders to standard therapies, in comparison with patients suffering from irritable bowel syndrome who were considered as controls, by using quantitative real-time polymerase chain reaction, immunohistochemistry and in situ hybridization, in an attempt to assess viral localization, DNA load, life cycle phase and possible correlation with disease activity indexes. We obtained clear evidence of the presence of high DNA loads of both viruses in either enterocytes or immune cells of refractory IBD patients, whereas we observed low levels in the responder group and an absence of detectable copies in all cell populations of controls. Remarkably, the values of EBV and HCMV DNA in inflamed mucosa were invariably higher than in non-inflamed areas in both IBD groups, and the EBV DNA loads in the cell populations of diseased mucosa of refractory IBD patients positively correlated with the severity of mucosal damage and clinical indexes of activity. Moreover, EBV infection resulted the most prevalent either alone or in combination with HCMV, while immunohistochemistry and in situ hybridization did not allow us to distinguish between the different phases of viral life cycle. Finally, as regards treatment, these novel findings could pave the way for the use of new antiviral molecules in the treatment of this condition.

Long-term microbiota and virome in a Zürich patient after fecal transplantation against Clostridium difficile infection

Fecal microbiota transplantation (FMT) is an emerging therapeutic option for Clostridium difficile infections that are refractory to conventional treatment. FMT introduces fecal microbes into the patient's intestine that prevent the recurrence of C. difficile, leading to rapid expansion of bacteria characteristic of healthy microbiota. However, the long-term effects of FMT remain largely unknown. The C. difficile patient described in this paper revealed protracted microbiota adaptation processes from 6 to 42 months post-FMT. Ultimately, bacterial communities were donor similar, suggesting sustainable stool engraftment. Since little is known about the consequences of transmitted viruses during C. difficile infection, we also interrogated virome changes. Our approach allowed identification of about 10 phage types per sample that represented larger viral communities, and phages were found to be equally abundant in the cured patient and donor. The healthy microbiota appears to be characterized by low phage abundance. Although viruses were likely transferred, the patient established a virome distinct from the donor. Surprisingly, the patient had sequences of algal giant viruses (chloroviruses) that have not previously been reported for the human gut. Chloroviruses have not been associated with intestinal disease, but their presence in the oropharynx may influence cognitive abilities. The findings suggest that the virome is an important indicator of health or disease. A better understanding of the role of viruses in the gut ecosystem may uncover novel microbiota-modulating therapeutic strategies.

Intestinal Behçet's Disease: A True Inflammatory Bowel Disease or Merely an Intestinal Complication of Systemic Vasculitis?

Behçet's disease (BD) is a multi-systemic inflammatory disorder of an unknown etiology and shows a chronic recurrent clinical course. When the disease involves the alimentary tract, it is called intestinal BD because of its clinical importance. Intestinal BD is more frequently reported in East Asian countries than in Western or Middle Eastern countries. While any part of the gastrointestinal tract can be involved, the most common location of intestinal BD is the ileocecal area. A few, large, deep ulcerations with discrete border are characteristic endoscopic findings of intestinal BD. Currently, there is no single gold standard test or pathognomonic finding of intestinal BD. However, recently developed novel diagnostic criteria and a disease activity index have helped in assessing intestinal BD. As intestinal BD shares a lot of characteristics with inflammatory bowel disease, including genetic background, clinical manifestations, and therapeutic strategies, distinguishing between the two diseases in clinical practice is quite difficult. However, biologic agents such as anti-tumor necrosis factor α antibody shows a considerable efficacy similar to inflammatory bowel disease cases. It is important to distinguish and treat those two disease entities separately from the standpoint of precise medicine. Clinicians should require comprehensive knowledge regarding the similarities and differences between intestinal BD and inflammatory bowel disease for making an accurate clinical decision.

Effects of Mycotoxins on mucosal microbial infection and related pathogenesis

Mycotoxins are fungal secondary metabolites detected in many agricultural commodities and water-damaged indoor environments. Susceptibility to mucosal infectious diseases is closely associated with immune dysfunction caused by mycotoxin exposure in humans and other animals. Many mycotoxins suppress immune function by decreasing the proliferation of activated lymphocytes, impairing phagocytic function of macrophages, and suppressing cytokine production, but some induce hypersensitive responses in different dose regimes. The present review describes various mycotoxin responses to infectious pathogens that trigger mucosa-associated diseases in the gastrointestinal and respiratory tracts of humans and other animals. In particular, it focuses on the effects of mycotoxin exposure on invasion, pathogen clearance, the production of cytokines and immunoglobulins, and the prognostic implications of interactions between infectious pathogens and mycotoxin exposure.

Human cytomegalovirus and Epstein-Barr virus infection in inflammatory bowel disease: Need for mucosal viral load measurement

AIM: To evaluate the best diagnostic technique and risk factors of the human Cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) infection in inflammatory bowel disease (IBD).

METHODS: A cohort of 40 IBD patients (17 refractory) and 40 controls underwent peripheral blood and endoscopic colonic mucosal sample harvest. Viral infection was assessed by quantitative real-time polymerase chain reaction and immunohistochemistry, and correlations with clinical and endoscopic indexes of activity, and risk factors were investigated.

RESULTS: All refractory patients carried detectable levels of HCMV and/or EBV mucosal load as compared to 13/23 (56.5%) non-refractory and 13/40 (32.5%) controls. The median DNA value was significantly higher in refractory (HCMV 286 and EBV 5.440 copies/10⁵ cells) than in non-refractory (HCMV 0 and EBV 6 copies/10⁵ cells; P < 0.05 and < 0.001) IBD patients and controls (HCMV and EBV 0 copies/10⁵ cells; P < 0.001 for both). Refractory patients showed DNA peak values ≥ 10³ copies/10⁵ cells in diseased mucosa in comparison to non-diseased mucosa (P < 0.0121 for HCMV and < 0.0004 for EBV), while non-refractory patients and controls invariably displayed levels below this threshold, thus allowing us to differentiate viral colitis from mucosal infection. Moreover, the mucosal load positively correlated with the values found in the peripheral blood, whilst no correlation with the number of positive cells at immunohistochemistry was found. Steroid use was identified as a significant risk factor for both HCMV (P = 0.018) and EBV (P = 0.002) colitis. Finally, a course of specific antiviral therapy with ganciclovir was successful in all refractory patients with HCMV colitis, whilst refractory patients with EBV colitis did not show any improvement despite steroid tapering and discontinuation of the other medications.

CONCLUSION: Viral colitis appeared to contribute to mucosal lesions in refractory IBD, and its correct diagnosis and management require quantitative real-time polymerase chain reaction assay of mucosal specimens.

Clinical and pathologic characteristics of inflammatory bowel disease

AIM: To investigate the clinical and pathological characteristics of inflammatory bowel disease to raise the early diagnosis of this disease.

METHODS: One hundred and twenty-two cases of inflammatory bowel disease including 101 cases of ulcerative colitis and 21 cases of Crohn's disease were analyzed.

RESULTS: Non-necrotizing granuloma, fissure ulcer and chronic inflammation were morphological features of Crohn's disease. Massive inflammatory cell infiltration in the lamina propria, destroyed glands and reduced secretion, and polyangitis were the hallmarks of ulcerative colitis.

CONCLUSION: The diagnosis of inflammatory bowel disease should be made based on endoscopic, macroscopic and clinical findings. Awareness of the clinical and pathologic features of inflammatory bowel disease can help make an early diagnosis of this disease.