Cytomegalovirus infection in patients with ulcerative colitis diagnosed by quantitative real-time PCR analysis

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.

High mucosal cytomegalovirus DNA helps predict adverse short-term outcome in acute severe ulcerative colitis

BACKGROUND/AIMS

Predictors of short-term outcome of intravenous (IV) steroid therapy in acute severe ulcerative colitis (ASUC) have been well described, but the impact of cytomegalovirus (CMV) infection as a predictor of outcome remains debatable. We investigated the role of quantitative CMV polymerase chain reaction (PCR) as a predictor of short-term outcome in patients with ASUC.

METHODS

Consecutive patients with ASUC satisfying Truelove and Witts criteria hospitalized at All India Institute of Medical Sciences (AIIMS) from May 2016 to July 2019 were included; all received IV steroid. The primary outcome measure was steroid-failure defined as the need for rescue therapy (with ciclosporin or infliximab) or colectomy during admission. AIIMS' index (ulcerative colitis index of severity > 6 at day 1+fecal calprotectin > 1,000 μg/g at day 3), with quantitative CMV PCR on biopsy samples obtained at initial sigmoidoscopy were correlated with the primary outcome.

RESULTS

Thirty of 76 patients (39%) failed IV corticosteroids and 12 (16%) underwent surgery. Patients with steroid failure had a significantly higher mucosal CMV DNA than responders (3,454 copies/mg [0-2,700,000] vs. 116 copies/mg [0-27,220]; P< 0.01). On multivariable analysis, mucosal CMV DNA load > 2,000 copies/mg (odds ratio [OR], 10.2; 95% confidence interval [CI], 2.6-39.7; P< 0.01) and AIIMS' index (OR, 39.8; 95% CI, 4.4-364.4; P< 0.01) were independent predictors of steroid-failure and need for colectomy. The combination correctly predicted outcomes in 84% of patients with ASUC.

CONCLUSIONS

High mucosal CMV DNA ( > 2,000 copies/mg) independently predicts failure of IV corticosteroids and short-term risk of colectomy and it has an additional value to the established markers of disease severity in patients with ASUC.

Current Diagnostic and Therapeutic Approaches to Cytomegalovirus Infections in Ulcerative Colitis Patients Based on Clinical and Basic Research Data

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus (the human herpesvirus 5) and an opportunistic pathogen that primarily infects HIV-positive and other immuno-compromised patients. Retrospective studies in the field of inflammatory bowel disease (IBD) have suggested a relationship between a concomitant colonic HCMV infection and poor outcomes in patients with an ulcerative colitis (UC) due to the presence of HCMV in surgical specimens of patients with a toxic megacolon or a steroid-resistant UC. Therefore, gastroenterologists have focused on the contribution of HCMV infections in the exacerbation of UC. Numerous studies have addressed the benefits of treating colonic HCMV reactivation in UC using an antiviral treatment. However, its clinical relevance remains uncertain as only a few prospective studies have assessed the direct relationship between clinical outcomes and the viral load of HCMV in colonic tissues. HCMV reactivation can be triggered by inflammation according to fundamental research studies. Thus, optimal control of intestinal inflammation is essential for preventing an HCMV reactivation in the intestinal mucosa. Indeed, several reports have indicated the effectiveness of an anti-tumor necrosis factor-alpha (TNFα) treatment in patients with an active UC and concomitant HCMV infections. In this review, we describe the mechanism of HCMV reactivation in UC cases and discuss the current issues regarding diagnosis and treatment of HCMV infections in UC patients.

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.

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.

Cytomegalovirus Colitis, Cytomegalovirus Hepatitis and Systemic Cytomegalovirus Infection: Common Features and Differences

Cytomegalovirus (CMV) is a ubiquitous human herpes virus, which, after often asymptomatic primary infection, establishes a lifelong latent infection that can periodically be reactivated in both immunocompetent and immunosuppressed carriers. Whereas the diagnostic approach in case of a suspicion of CMV reactivation is well defined, the indication for antiviral therapy can often only be made in the context of an extent of organ involvement, the immune status, and comorbidities of the patient. This article reviews the epidemiology, diagnosis, and therapy of CMV reactivation with a focus on inflammatory bowel diseases and potentially different diagnostic and therapeutic approaches in Asia and the Western world.

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.

Tacrolimus or infliximab for severe ulcerative colitis: short-term and long-term data from a retrospective observational study

Objective

Treatment of severe ulcerative colitis (UC) is challenging. Although the efficacy of tacrolimus (TAC) and infliximab (IFX) have been evaluated in patients with severe UC, the safety and efficacy levels of sequential therapies (TAC→IFX/IFX→TAC) in these patients remain unclear. The aim of this study was to assess short-term and long-term outcomes in patients with severe UC treated with TAC and IFX.

Methods

From October 2001 to February 2014, 29 patients with consecutive severe UC treated with TAC or IFX were retrospectively evaluated. Median follow-up duration was 27 months (range 0.5–118 months). The primary end point was short-term outcomes at 8 weeks after induction of TAC (TAC group, n=22) or IFX (IFX group, n=7). The secondary end point included long-term outcomes and colectomy-free survival. The clinical response was evaluated based on a partial Mayo score.

Results

The clinical remission (CR) rate at 8 weeks in the TAC and IFX groups was 63.6% and 71.4%, respectively. In 13 of the 29 patients (10 in the TAC group, 3 in the IFX group), sequential therapies were used in their clinical courses. In 9 of these 13 patients (6 in the TAC group, 3 in the IFX group), CR was achieved and maintained by sequential therapies. Overall cumulative colectomy-free survival was 79.3% at 118 months.

Conclusions

TAC and IFX had similar effects on remission induction in patients with severely active UC. Sequential therapies could rescue patients with UC who failed initial treatment with TAC or IFX. In clinical practice, sequential therapies might be deliberately performed.

Cytomegalovirus infection and postoperative complications in patients with ulcerative colitis undergoing colectomy

BACKGROUND

Ulcerative colitis (UC) can be complicated by reactivation of cytomegalovirus (CMV). CMV reactivation may change the course of UC and may require antiviral treatment. Some risk factors of CMV reactivation have previously been identified, whereas the association between CMV reactivation and postoperative complications has not been examined systematically.

METHODS

Patients with UC operated with colectomy due to active UC were studied (n = 77). Patient and disease characteristics, as well as postoperative complications were recorded and CMV was detected by immunohistochemical examination of multiple sections from the colectomy specimen.

RESULTS

CMV was found in nine (11.7%) colectomy specimens. CMV-positive patients received significantly higher doses of corticosteroids at colectomy than CMV-negative patients (61.1 ± 23 vs 32.5 ± 32 mg/day, p = 0.01). CMV-positive patients were also older, had a higher risk of severe complications, higher American Society of Anesthesiologists (ASA) score, longer preoperative stay, and a higher rate of acute surgery. Complications occurred in 30 (39%) patients after surgery, 8(10.4%) of whom were serious. Two CMV-positive patients (2.6%) died in-hospital after the colectomy. High ASA score was associated with the occurrence of serious complications.

CONCLUSION

A relatively small proportion of patients with UC operated by colectomy were CMV positive. CMV positivity was associated with old age, high dose of corticosteroids at operation, high ASA score, acute surgery, and severe postoperative complications. Patients with such characteristics may be at risk of CMV infection and may require special management.

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.

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.

Neutralizing antibodies against adeno-associated viruses in inflammatory bowel disease patients: implications for gene therapy

BACKGROUND

Inflammatory bowel diseases (IBDs) are comprised of two major disorders: Crohn's disease (CD) and ulcerative colitis (UC). No curative treatment options are available, but gene therapy may offer an alternative therapeutic approach. For this a safe and reliable vector is needed. The adeno-associated viruses (AAV) have attracted considerable interest as gene therapy vectors. However, neutralizing antibodies (nAb's) made in response to wildtype AAV have been associated with a partial to complete block of transduction in case of reexposure. Therefore, and in order to define AAV vector candidates to treat IBD patients, we characterized preexisting humoral responses to AAV in this population.

METHODS

We measured circulating antibodies against AAV serotypes 1, 2, 3, 4, 5, 6, and 8 using a previously established virus neutralization assay. In all, 100 healthy donors and 200 IBD patient's serum samples (101 CD and 99 UC) were analyzed.

RESULTS

A significant difference was detected in the prevalence of nAb's for AAV types 1, 5, 6, and 8 between the healthy donors and the patient population. Furthermore, various disease phenotypic characteristics correlated with the prevalence of nAb's to all the serotypes studied.

CONCLUSIONS

Our study establishes a foundation for the development of an AAV-based gene therapy approach as a novel treatment for IBD. Furthermore, we show a relationship between disease phenotype in IBD patients and the humoral immune response to AAV.

Cytomegalovirus load in inflamed intestinal tissue is predictive of resistance to immunosuppressive therapy in ulcerative colitis

OBJECTIVES

Previous studies have suggested an association between cytomegalovirus (CMV) infection and steroid-refractory inflammatory bowel disease. In this study, the use of CMV DNA load during acute flare-ups of ulcerative colitis (UC) to predict resistance to immunosuppressive therapy was evaluated in intestinal tissue.

METHODS

Forty-two consecutive patients (sex ratio M/F: 0.9, mean age: 43.6 years) hospitalized for moderate to severe UC and treated with IV steroids were included prospectively. A colonoscopy was performed for each patient at inclusion; colonic biopsy samples of the pathological tissue, and if possible, of the healthy mucosa, were tested for histological analysis and determination of CMV DNA load by real-time polymerase chain reaction assay. Patients were treated as recommended by the current guidelines.

RESULTS

Sixteen patients were found positive for CMV DNA in inflamed intestinal tissue but negative in endoscopically healthy tissue; all of these patients were positive for anti-CMV IgG, three exhibited CMV DNA in blood, and none was positive for intestinal CMV antigen by immunohistochemistry detection. In the 26 remaining patients, no stigmata of recent CMV infection were recorded by any technique. By multivariate analysis, the only factor associated with CMV DNA in inflammatory tissue was the resistance to steroids or to three lines of treatment (risk ratio: 4.7; 95% confidence interval: 1.2-22.5). A CMV DNA load above 250 copies/mg in tissue was predictive of resistance to three successive regimens (likelihood ratio+=4.33; area under the receiver-operating characteristic curve=0.85). Eight UC patients with CMV DNA in inflamed tissue and therapeutic failure received ganciclovir; a clinical remission was observed in seven cases, with a sustained response in five of them.

CONCLUSIONS

The CMV DNA load determined in inflamed intestinal tissue predicts resistance to steroid treatment and to three drug regimens in UC. Initiation of an early antiviral treatment in these patients might delay the occurrence of resistance to current treatments.

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

AIM: To evaluate the natural history of human cytomegalovirus (HCMV) infection in a series of 28 ulcerative colitis patients in whom the search for HCMV was positive.

METHODS: A series of 85 patients with moderate-severe ulcerative colitis flare-up were evaluated for a HCMV search by performing a haematoxylin and eosin stain, immunohistochemical assay and nested polymerase chain reaction on rectal biopsies. Among 85 screened patients (19 of whom were steroid resistant/dependant), 28 were positive for HCMV; after remission the patients were followed up clinically and histologically.

RESULTS: Among the 22 patients with complete follow-up, in 8 (36%) patients HCMV-DNA persisted in the intestinal specimens. Among the HCMV positive patients, 4 (50%) experienced at least one moderate-severe flare-up of colitis without evidence of peripheral HCMV. Among the 14 HCMV negative patients, 3 with pouches developed pouchitis and 5 out of 11 (45%) experienced a colitis flare-up.

CONCLUSION: Our preliminary results suggest that HCMV may remain in the colon after an acute colitis flare-up despite remission; it seems that the virus is not responsible for the disease relapse.

Evaluation of a non-invasive method to detect cytomegalovirus (CMV)-DNA in stool samples of patients with inflammatory bowel disease (IBD): a pilot study

BACKGROUND

A severe flare of colitis in patients with IBD treated with immunosuppressive therapy may be complicated by an underlying CMV infection. The aim of this pilot study was to investigate the diagnostic efficacy of quantitative polymerase chain reaction (PCR) to detect CMV DNA in stool samples of IBD patients.

METHODS

Twenty-one patients with a severe flare of IBD, incompletely responding or refractory to either steroids or immunosuppressive agents, were included in the study. Nineteen patients completed the study according to the protocol undergoing an endoscopy with biopsies and collection of stool samples. Biopsy and stool samples were qualitatively and quantitatively analyzed for CMV DNA using real-time PCR.

RESULTS

Thirty-two percent (6/19) of the patients had detectable CMV DNA in colonic biopsies and in five (83%) of those patients CMV DNA was detected in the stool. Thirteen patients had negative findings for CMV DNA in biopsy and stool samples. The sensitivity, specificity, and accuracy of the PCR-based stool test for detection of CMV DNA compared to PCR-based detection of CMV in mucosal biopsies were 83, 93, and 90%, respectively.

CONCLUSIONS

The pilot study suggests a high accuracy of this non-invasive testing method to detect CMV DNA in stool samples as compared to mucosal biopsies. This approach may offer a non-endoscopic testing modality for underlying CMV infection in patients with a severe flare of IBD, which could also be applied more broadly to determine the prevalence of CMV infections in patients with IBD.

Acute Epstein-Barr virus infection presenting as severe gastroenteritis without infectious mononucleosis-like manifestations

Primary Epstein-Barr virus (EBV) infection is usually a self-limiting disease. Although it is sometimes accompanied by severe complications such as thrombocytopenia, hemolytic anemia, and splenic rupture, predominantly gastrointestinal complications are rarely reported. We studied an unusual case of primary EBV infection associated with severe hemorrhagic gastroenteritis. EBV infection was confirmed in the biopsy specimen by demonstrating the presence of EBV DNA by polymerase chain reaction, and of EBV-encoded small RNA (EBER)-positive cells by in-situ hybridization. Our patient was suspected of having primary EBV infection from the serological findings-EBV-viral capsid antigen IgM (+) and EBV nuclear antigen (-)-but he did not show typical clinical features of infectious mononucleosis such as lymph node swelling, pharyngitis, liver dysfunction, and splenomegaly. A definite diagnosis of primary EBV infection was made using biopsy specimens by demonstrating the presence of EBV DNA and EBER-positive cells.

Usefulness of quantitative real-time PCR assay for early detection of cytomegalovirus infection in patients with ulcerative colitis refractory to immunosuppressive therapies

BACKGROUND

Studies suggest that cytomegalovirus (CMV) infection exacerbates ulcerative colitis (UC) refractory to immunosuppressive therapies. Early and accurate diagnosis of CMV infection is important for the treatment of UC. We evaluated the usefulness of quantitative real-time polymerase chain reaction (PCR) for detecting CMV infection in inflamed colonic mucosa of patients with UC refractory to immunosuppressive therapies.

METHODS

From 2003 to 2006, 30 patients (mean age: 41 +/- 18 years; 14 men, 16 women) with UC refractory to immunosuppressive therapies were enrolled in the study. We evaluated CMV infection by CMV antigenemia, histologic examination, and quantitative real-time PCR for CMV using colonic mucosa and investigated the clinical outcomes of antiviral therapy.

RESULTS

CMV-DNA was detected only in the inflamed colonic mucosa in 17 (56.7%) of 30 patients. Of the 17 CMV-DNA-positive patients, 4 were positive for CMV antigenemia or inclusion bodies on histologic examination; of the 13 CMV-DNA-negative patients none was positive for CMV antigenemia or inclusion bodies. Of the 17 CMV-DNA-positive patients, 12 (70.6%) were treated with ganciclovir for 2 weeks and 10 patients went into remission. Two other patients required colectomy after antiviral therapy. In contrast, of the 13 CMV-DNA-negative patients 12 (92.3%) achieved remission after intensifying their immunosuppressive therapies.

CONCLUSIONS

Quantitative real-time PCR assay for detecting CMV-DNA is useful for early, accurate diagnosis of CMV infection in patients with UC refractory to immunosuppressive therapies, enabling prompt and appropriate treatment.