Clinical and immunologic aspects of cytomegalovirus infection in solid organ transplant recipients

Radiation proctitis with recurrent gastrointestinal bleeding complicated by cytomegalovirus

Cytomegalovirus (CMV) usually causes infections with mild symptoms in immunocompetent individuals. However, in immunocompromised patients, these infections can be serious or life-threatening. Following initial infection, CMV typically becomes dormant but remains lifelong in the host. Reactivation of the latent virus can occur in many organ systems, including the gastrointestinal (GI) tract. Radiation proctitis is a known risk factor associated with prostate radiation, with complicating ulceration and GI bleeding. We present the first case report of an immunocompetent 81-year-old male with multiple episodes of life-threatening GI bleeding, secondary to a non-healing CMV-positive rectal ulcer and CMV colitis following radiation for prostate cancer. Multiple insults including prostate radiation, repeated blood transfusions and CMV infection likely contributed to the recurrent bleeding episodes.

Prevalence and Risk Factors of Cytomegalovirus Colitis in Inflammatory Bowel Disease Patients in Riyadh, Saudi Arabia: A Tertiary Center Experience

Background

Patients with inflammatory bowel disease (IBD) are at a higher risk of cytomegalovirus (CMV) colitis because of their immunocompromised status. There are no studies from Saudi Arabia regarding the prevalence of CMV colitis in patients with IBD.

Objective

To determine the prevalence, characteristics, and risk factors of CMV colitis in patients with IBD in Riyadh, Saudi Arabia.

Materials and Methods

This retrospective study included patients with a confirmed diagnosis of IBD (aged 14-75 years) who were followed up at King Fahad Medical City, a referral care center in Riyadh, between January 2016 and December 2021; patients with indeterminate colitis or incomplete medical records were excluded.

Results

A total of 341 patients with IBD were included, of which 236 (72.2%) had Crohn's disease (CD) and 105 (27.8%) had ulcerative colitis (UC). Qualitative CMV PCR was done for 192 patients (60 UC and 132 CD patients), of which 14 patients were positive for CMV colitis (7.3%), and all positive CMV colitis cases were among UC patients (23.3%). However, the hematoxylin and eosin (H and E) stain and immunohistochemistry were negative for all patients. Most patients with CMV colitis were on steroids (71.4%), had at least one flare-up (64.3%), and were on biologic treatment (71.4%). Significant predictors of CMV colitis were hemoglobin (OR: 0.7; 95% CI: 0.51-0.96), albumin (OR: 0.88; 95% CI: 0.78-0.98), and C-reactive protein (OR: 1.03; 95% CI: 1.01-1.06) levels.

Conclusion

This study found that the prevalence of CMV colitis was 7.3% among patients with IBD, and no case was diagnosed in patients with CD. In addition, as all cases diagnosed using qualitative CMV PCR were negative on H and E stain and immunohistochemistry, there is need for large-scale studies to improve the diagnosis of CMV colitis.

The essential role of intestinal microbiota in cytomegalovirus reactivation

Human cytomegalovirus (HCMV) is a member of Herpesviridae. It has been reported that HCMV is reactivated in the breast milk of HCMV-seropositive lactating women. As we have reported various aspects of the roles of indigenous microbiota, its role in the murine CMV (MCMV) reactivation was examined in this study. MCMV was latently infected in the salivary gland, mammary tissues, and colon in the pregnant mice. When the salivary gland, mammary tissues, and colon were removed 5 days after delivery, MCMV reactivation of latent infection in each organ was confirmed by the detection of MCMV IE1 mRNA using reverse transcription-quantitative PCR. MCMV reactivation was observed in 100% of the mice during pregnancy. Next, for the elimination of intestinal microbiota, the pregnant mice were treated with low-dose or high-dose non-absorbable antibiotics. Although the numbers of aerobe/anaerobe in cecal content in low-dose antibiotic-treated mice were comparable to those in untreated controls, high-dose antibiotic treatment decreased the number of aerobe/anaerobe microbes from ca.9.0 Log10 to ca.3.0 Log10 (cfu/g). However, it could not be confirmed in 16S rRNA analysis that specific bacterial phylum or genus was eliminated by this high-dose treatment. Interestingly, MCMV reactivation was also observed in 100% of low-dose antibiotic-treated mice, whereas, in high-dose antibiotic-treated mice, MCMV reactivation was not observed in the salivary gland or colon. MCMV IE1 mRNA was detected only in 33% of the mammary tissues of those high-dose-treated mice. These results suggest that the indigenous microbiota played a crucial role in the reactivation of latent infection. IMPORTANCE Human cytomegalovirus (HCMV) infection via breast milk is a serious problem for very preterm infants such as developing a sepsis-like syndrome, cholestasis, or bronchopulmonary dysplasia, among others. It has been reported that HCMV is reactivated in the breast milk of HCMV-seropositive lactating women. In this study, the roles of indigenous microbiota in the murine CMV (MCMV) reactivation were examined using a mouse model. In MCMV latently infected mice, MCMV reactivation was observed in 100% of the mice during pregnancy. For the elimination of intestinal microbiota, MCMV-latent mice were treated with non-absorbable antibiotics. After delivery, MCMV reactivation was not observed in antibiotic-treated mice. This result suggested that the indigenous microbiota played a crucial role in the reactivation of latent infection.

Increased CMV disease and "severe" BK viremia with belatacept vs. sirolimus three-drug maintenance immunosuppression

OBJECTIVES

Belatacept may provide benefit in delayed graft function, but its association with infectious complications is understudied. We aim to assess the incidence of CMV and BK viremia in patients treated with sirolimus or belatacept as part of a three-drug immunosuppression regimen after kidney transplantation.

MATERIALS AND METHODS

Kidney transplant recipients from 01/01/2015 to 10/01/2021 were retrospectively reviewed. Maintenance immunosuppression was either tacrolimus, mycophenolate and sirolimus (B0) or tacrolimus, mycophenolate, and belatacept (5.0 mg/kg monthly) (B1). Primary outcomes of interest were BK and CMV viremia which were followed until the end of the study period. Secondary outcomes included graft function (serum creatinine, eGFR) and acute rejection through 12 months.

RESULTS

Belatacept was initiated in patients with a higher mean kidney donor profile index (B0:0.36 vs. B1:0.44, p = .02) with more delayed graft function (B0:6.1% vs. B1:26.1%, p < .001). Belatacept therapy was associated with more "severe" CMV viremia >25,000 copies/mL (B0:1.2% vs. B1:5.9%, p = .016) and CMV disease (B0:0.41% vs. B1:4.2%, p = .015). However, there was no difference in the overall incidence of CMV viremia >200 IU/mL (B0:9.4% vs. B1:13.5%, p = .28). There was no difference in the incidence of BK viremia >200 IU/mL (B0:29.7% vs. B1:31.1%, p = .78) or BK-associated nephropathy (B0:2.4% vs. B1:1.7%, p = .58), but belatacept was associated with "severe" BK viremia, defined as >10,000 IU/mL (B0:13.0% vs. B1:21.8%, p = .03). The mean serum Cr was significantly higher with belatacept therapy at 1-year follow up (B0:1.24 mg/dL vs. B1:1.43 mg/dL, p = .003). Biopsy-proven acute rejection (B0:1.2% vs. B1:2.6%, p = .35) and graft loss (B0:1.2% vs. B1:0.84%, p = .81) were comparable at 12 months.

CONCLUSIONS

Belatacept therapy was associated with an increased risk of CMV disease and "severe" CMV and BK viremia. However, this regimen did not increase the overall incidence of infection and facilitated comparable acute rejection and graft loss at 12-month follow up.

The Value of Single-cell Technologies in Solid Organ Transplantation Studies

Single-cell technologies open up new opportunities to explore the behavior of cells at the individual level. For solid organ transplantation, single-cell technologies can provide in-depth insights into the underlying mechanisms of the immunological processes involved in alloimmune responses after transplantation by investigating the role of individual cells in tolerance and rejection. Here, we review the value of single-cell technologies, including cytometry by time-of-flight and single-cell RNA sequencing, in the context of solid organ transplantation research. Various applications of single-cell technologies are addressed, such as the characterization and identification of immune cell subsets involved in rejection or tolerance. In addition, we explore the opportunities for analyzing specific alloreactive T- or B-cell clones by linking phenotype data to T- or B-cell receptor data, and for distinguishing donor- from recipient-derived immune cells. Moreover, we discuss the use of single-cell technologies in biomarker identification and risk stratification, as well as the remaining challenges. Together, this review highlights that single-cell approaches contribute to a better understanding of underlying immunological mechanisms of rejection and tolerance, thereby potentially accelerating the development of new or improved therapies to avoid allograft rejection.

Sarcopenia and risk of infection in adult heart transplant recipients in Japan

AIMS

Heart transplantation (HT) is an effective therapeutic option for end-stage heart failure. Infection is a major cause of morbidity and mortality after HT. Sarcopenia, defined as the loss of muscle mass and strength, is a common comorbidity in HT candidates with end-stage heart failure. However, the effects of sarcopenia on the occurrence of post-HT infections are not well understood. Therefore, we explored the association between the skeletal muscle mass and post-transplant infections in adult HT recipients.

METHODS AND RESULTS

We retrospectively examined the records of 135 patients who underwent HT between August 2007 and November 2019 at our institution. Pre-transplant computed tomography was used to calculate the skeletal muscle index (SMI) at the level of the third lumbar vertebra. Muscle wasting was defined as the SMI of the lowest sex-based tertiles. The primary endpoint was infections within 6 months of HT. The study included 109 patients (80 men, mean age: 41.6 ± 12.0 years): 37 patients in the muscle wasting group and 72 patients in the non-muscle wasting group. The mean SMI values in the muscle wasting and non-muscle wasting groups were 29.9 ± 4.8 cm² /m² and 40.7 ± 6.7 cm² /m² , respectively. Prior to HT, 108 (99.1%) patients were on left ventricular assist device support, and during that support, the rate of late right heart failure was significantly higher in the muscle wasting group than non-muscle wasting group (P = 0.012). Sixteen infections occurred within 6 months of HT. The most common infection sites included the respiratory tract (n = 5) and the upper gastrointestinal tract (n = 5), followed by the urinary tract (n = 4). Overall, 10 patients experienced infections in the muscle wasting group (27.0%) and 6 in the non-muscle wasting group (8.3%) (P = 0.009). Two patients in the muscle wasting group required intensive care unit admission, compared to none in the non-muscle wasting group. Low skeletal muscle mass was associated with infections in the univariate and multivariate logistic regression models (hazard ratio: 3.68, 95% confidence interval: 1.19-11.3; P = 0.023). However, the duration of all-cause mortality within 3 years did not differ between the groups (P = 0.56).

CONCLUSIONS

Low skeletal muscle mass is a predictor of post-HT infections within 6 months of HT.

Valganciclovir prophylaxis extension from 3 to 6 months in high-risk pancreas-transplant recipients does not impact incidence of cytomegalovirus infection at 12 months

PROBLEM

Incidence and impact of CMV infection in pancreas-transplant recipients (PTRs) in the valganciclovir prophylaxis era has not been completely elucidated.

METHODS

Adult D+/R- PTRs were divided into a current era (1/1/2011-12/31/17; 6-month PPX) and a historic era (1/1/2003-12/31/09; 3-month PPX).

PRIMARY OBJECTIVE

effect of prophylaxis extension on the incidence of CMV infection.

SECONDARY OBJECTIVE

impact of extension on valganciclovir-related toxicity (leukopenia) and transplant outcomes.

RESULTS

There were 177 D+/R- PTRs in the study period (historic:98, current:79). Prophylaxis extension resulted in significant reduction of CMV infection from 25.4% to 10.9% at 6 months, (57% reduction, p = .021). However, 1-year rates of CMV infection (historic:31% vs current:36%) and end-organ disease (historic:7.7% vs current:6.9%) were not different (p = .93). Prophylaxis extension significantly increased leukopenia (white blood cell count<3 K/uL) at 6 months (historic:9.5% vs current:28.6%, p = .018). On multivariable analysis prophylaxis extension was not associated with reduced rates of CMV infection (p = .99) or CMV end-organ disease (p = .3). Additionally, there was no significant difference in rejection (p = .2), graft survival (p = .08), death-censored graft survival(p = .07) or patient survival (p = .6).

CONCLUSIONS

Prophylaxis extension in D+/R- PTRs appears to delay time to first CMV but not reduce overall incidence. These findings suggest a hybrid approach, incorporating antiviral withdrawal and protocolized monitoring, may be needed to improve CMV-related outcomes.

Cytomegalovirus in urinary sediment in patients with acute kidney injury

Background

Immunosuppression in solid organ transplantation is associated with frequent infections. Renal allograft recipients are susceptible to opportunistic infections and can acquire human cytomegalovirus (HCMV) infections even within the allograft. There, HCMV can be found in both the glomerulus and tubular cells, but is mostly restricted to specific and circumscribed sites. Therefore, not all organ infections are identifiable by immunohistology for HCMV proteins in fine needle core biopsies. Thus, we performed a urinalysis study to search for HCMV-specific RNA transcripts in the urine sediment of patients with acute kidney injury.

Methods

Urinary sediment of 90 patients with acute kidney injury (AKI), including 48 renal transplant recipients (RTX) and 42 non-transplant recipients (nRTX), was collected from morning urine for RNA extraction and reverse transcription. The copy number of HCMV transcripts was evaluated using a UL132 HCMV-specific probe set and by real-time quantitative polymerase chain reaction (RT-qPCR).

Results

Of the 48 RTX patients, ten showed HCMV copies in their urine sediment cells. Within this group, three recipients had negative HCMV serology and received an allograft from an HCMV-seropositive donor. In addition, all three RTX patients on a belatacept-based immunosuppressive regimen had HCMV transcripts in their urine. Of the 42 nRTX patients, only two had detectable HCMV transcripts in urine sediment cells and both were under immunosuppression.

Conclusions

Ten immunosuppressed renal allograft recipients and two immunosuppressed non-transplant patients with AKI showed HCMV copies in urine sediment. Thus, HCMV positivity in urinary sediment appears to be associated with immunosuppression. This study describes a novel noninvasive method for detection of HCMV in urinary sediment. Whether all HCMV infections can be detected or only those with viral replication warrants further investigation.

Cytomegalovirus antiviral stewardship in the COVID-19 Era: Increasing complexity of prophylaxis and treatment and potential mitigation strategies

Cytomegalovirus (CMV) infection is one of the most common and significant complications after solid organ transplant (SOT). Severe acute respiratory coronavirus 2 (SARS‐CoV‐2), which causes the novel betacoronavirus 2019 disease (COVID‐19), has become the first global pandemic in 100 years. The world's attention has turned to address this unanticipated development; however, the viral infection that has long plagued outcomes after solid organ transplantation still requires vigilance. With physical distancing as the key intervention to reduce the healthcare burden, and the unease related to healthcare contact within the transplant population given the associated morbidity and mortality of COVID‐19 in transplant recipients, providers have struggled to evaluate and streamline essential in‐person healthcare contact, including laboratory visits. Owing to this, the COVID‐19 pandemic has placed a significant strain on the delivery of CMV prophylaxis and treatment after solid organ transplantation. In this piece, we will describe issues our CMV antiviral stewardship service has encountered in the care of the transplant recipient with CMV during the this unprecedented time and share our expert opinion to approaches to providing optimal, evidenced based care during a pandemic associated with a seemingly unrelated viral infection.

Clinical features of BK-polyomavirus and cytomegalovirus co-infection after kidney transplantation

BK polyomavirus (BKPyV) and cytomegalovirus (CMV) are the main viral pathogens affecting the graft and recipient outcome after allogenic kidney transplantation. It has recently been found that infection with both viruses has a greater impact on kidney graft function than a single infection. We retrospectively analyzed a cohort of 723 recipients who received kidney transplantation between 2007 and 2015 after living and postmortal donation for differences in risk and outcome parameters regarding BKPyV (DNAemia) and CMV (CMV DNAemia) co-infection compared to sole viremias and to patients without viremia. Of all kidney allograft recipients in our cohort, 8.2% developed co-infection with BKPyV DNAemia and CMV DNAemia, 15.1% showed BKPyV viremia alone and 25.2% sole CMV DNAemia. Acute rejection was closely linked with co-infection (multivariable analysis, p = 0.001). Despite the fact that the estimated glomerular filtration rate of patients with co-infection was noticeably reduced compared to patients with BKV or CMV infection alone, transplant survival and patient survival were not significantly reduced. Co-infection with BKPyV and CMV in kidney transplanted patients is significantly associated with inferior allograft function. Since co-infection is strongly associated with acute rejection, co-infected individuals should be considered a risk collective.

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.

Biologic Immunomodulatory Drugs and Infection in the Respiratory Tract of Nonhuman Primates

Though rare due to measures and practices to control the risk, infections can occur in research and toxicology studies, especially in nonhuman primates (NHPs) exposed to xenobiotics, particularly immunomodulatory drugs. With such xenobiotics, immunocompromised or immunosuppressed animals will not be able to mount a protective response to infection by an opportunistic pathogen (bacteria, virus, parasite, or fungus) that might otherwise be nonpathogenic and remain clinically asymptomatic in immunocompetent animals. The respiratory tract is one of the most commonly affected systems in clinic, but also in toxicology studies. Pulmonary inflammation will be the main finding associated with opportunistic infections and may cause overt clinical disease with even early sacrifice or death, and may compromise or complicate the pathology evaluation. It is important to properly differentiate the various features of infection, to be aware of the range of possible opportunistic pathogens and how they may impact the interpretation of pathology findings. This review will present the most common bacterial, viral, parasitic, and fungal infections observed in the respiratory tract in NHPs during research and/or toxicology studies.

Cytomegalovirus Viremia after Living and Deceased Donation in Kidney Transplantation

Despite screening, effective anti-viral drugs and risk-balanced prophylaxis, cytomegalovirus (CMV) remains a major cause of morbidity in transplant patients. The objective of this study was to retrospectively analyze the risk factors associated with CMV viremia after kidney transplantation in a large European cohort with standardized valganciclovir prophylaxis in the present era. A special focus was placed on the comparison of living and postmortal donation. We conducted a longitudinal observational study involving 723 adult patients with a total of 3292 patient-years who were transplanted at our center between 2007 and 2015. Valganciclovir prophylaxis was administered over 100 days for CMV+ donors (D) or recipients (R), over 200 days for D+/R−, and none in D−/R−. A CMV+ donor, rejection episodes, and deceased donor transplantation were identified to be associated with increased incidences of CMV viremia. Although we did not find a reduced overall survival rate for patients with CMV viremia, it was associated with worse graft function. Since we observed a relevant number of CMV infections despite prescribing valganciclovir prophylaxis, a pre-emptive strategy in patients with (suspected) adherence restrictions could be favored. Our data can help transplant physicians educate their patients about their individual CMV risk and choose the most appropriate CMV treatment approach.

New Developments in the Management of Cytomegalovirus Infection After Transplantation

Cytomegalovirus (CMV) continues to be one of the most important pathogens that universally affect solid organ and allogeneic hematopoietic stem cell transplant recipients. Lack of effective CMV-specific immunity is the common factor that predisposes to the risk of CMV reactivation and clinical disease after transplantation. Antiviral drugs are the cornerstone for prevention and treatment of CMV infection and disease. Over the years, the CMV DNA polymerase inhibitor, ganciclovir (and valganciclovir), have served as the backbone for management, while foscarnet and cidofovir are reserved for the management of CMV infection that is refractory or resistant to ganciclovir treatment. In this review, we highlight the role of the newly approved drug, letermovir, a viral terminase inhibitor, for CMV prevention after allogeneic hematopoietic stem cell transplantation. Advances in immunologic monitoring may allow for an individualized approach to management of CMV after transplantation. Specifically, the potential role of CMV-specific T-cell measurements in guiding the need for the treatment of asymptomatic CMV infection and the duration of treatment of CMV disease is discussed. The role of adoptive immunotherapy, using ex vivo-generated CMV-specific T cells, is highlighted. This article provides a review of novel drugs, tests, and strategies in optimizing our current approaches to prevention and treatment of CMV in transplant recipients.

Cytomegalovirus infection in pediatric patients with hepatoblastoma after liver transplantation

No studies have examined CMV infection in pediatric patients with HB receiving LT. Here, we retrospectively analyzed the incidence of and risk factors for CMV infection in 24 pediatric patients with HB who underwent LT between 1997 and 2015. CMV infection was monitored by measuring expression of pp65 CMV antigen for up to 4 months post-LT. CMV infection, defined as detection of at least one pp65-positive leukocyte, was detected in nine (37.5%) patients who did not develop CMV disease. Nine (47.4%) of nineteen patients who received post-LT chemotherapy experienced CMV infection; however, no CMV infection was observed in the five patients who did not receive post-LT chemotherapy (P = 0.012). There were no significant differences in the incidence of CMV infection between patients with ACR (60.0%) and those without (21.4%, P = 0.092), or between CMV seropositive (55.6%) and seronegative patients (33.3%, P = 0.675). All nine patients with CMV infection did not experience CMV disease due to the use of preemptive antiviral therapy. Close monitoring of CMV infection is recommended for patients with HB, particularly those receiving post-LT chemotherapy. Preemptive antiviral therapy is feasible for prophylaxis of CMV disease.

Outcome of Cytomegalovirus Colitis in Inflammatory Bowel Disease with Different Regimes of Ganciclovir

BACKGROUND Cytomegalovirus (CMV) infection is common in individuals with inflammatory bowel disease (IBD) and is responsible for relapse, increased severity, and poor outcome if left untreated. Ganciclovir is the mainstay of treatment but data regarding its use, mode of administration, and duration of treatment is poorly described. We reviewed the practice of treating CMV colitis with different regimes of ganciclovir at a district NHS hospital to compare the clinical outcome. METHODS 35 patients with IBD and concurrent diagnosis of CMV infection were evaluated. The parameters studied were clinical outcome in term of clinical response, length of hospital stay, readmission, or colectomy with three different regimes of ganciclovir, in addition to treatment for IBD. RESULTS 35 patients with IBD (ulcerative colitis = 23, Crohn's disease = 5, Indeterminate colitis = 7) and positive diagnosis of CMV infection were studied. Clinical outcome with two weeks of intravenous (IV) ganciclovir regime was superior than one week of IV ganciclovir and two weeks of oral Valganciclovir in term of clinical response on day 15 (95.8% vs 74%, 24.3%, respectively p = 0.45) and colectomy rate within 3 months (6.25% vs 27.3%, vs 25%, respectively). CONCLUSION CMV colitis is associated with poor outcome in patient with IBD if left untreated. 2 weeks IV ganciclovir was associated with a better outcome than 1 week of IV treatment or oral treatment.

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.

Characteristics of cytomegalovirus enterocolitis in patients with or without inflammatory bowel diseases

OBJECTIVES

Cytomegalovirus (CMV) disease is more common in immunocompromised patients but may occur in people with normal immune function. In addition, CMV enterocolitis can aggravate inflammatory bowel diseases (IBD), but there was little knowledge of differences in clinical and endoscopic features of CMV enterocolitis between patients with IBD and without IBD. The aim of this study was to determine the difference in clinical implication in CMV enterocolitis between the IBD patients and non-IBD patients.

METHODS

This was a retrospective study of 82 patients with CMV enterocolitis based on the pathologic findings at two tertiary referral hospitals from 2003 to 2013. Clinical and endoscopic characteristics and clinical course were analyzed according to the presence of IBD.

RESULTS

Of the 82 patients, 25 (30.5%) had IBD and 57 (69.5%) did not have IBD. Hematochezia was more common in IBD patients (84.0% vs. 35.1%; p = .001), but fever and positive CMV antigenemia were more common in non-IBD patients (50.9% vs. 12.0%; p = .001; 54.4% vs. 28.0; p = .027). Endoscopic findings showed more ulcer with inflammation in IBD patients (68.0% vs. 35.2%; p = .005). Sixty-four patients were treated with antiviral agents and 12 patients who did not receive antiviral agents recovered spontaneously. All naturally healed patients were in normal immune status.

CONCLUSIONS

Hematochezia is more common in IBD patients and fever/CMV antigenemia is more common in patients without IBD. In patients without IBD, the natural resolution of CMV enterocolitis is expected at least in normal immune function.

Antiviral Treatment for Colonic Cytomegalovirus Infection in Ulcerative Colitis Patients Significantly Improved Their Surgery Free Survival

BACKGROUND

The frequency of cytomegalovirus (CMV) colitis in steroid-refractory inflammatory bowel disease has been reported to range from 15.8% to 34.0%. Infected patients are more likely to become hospitalized, have longer lengths of stay, and higher mortality rates. Current data are limited to small scale studies and showed conflicting result regarding the role of antiviral therapy.

AIMS

(1) To investigate the role of antiviral treatment in ulcerative colitis (UC) patients with CMV infection. (2) To investigate the role of viremia in the outcomes of these patients.

MATERIALS AND METHODS

The Cleveland Clinic pathology database identified 1478 patients who had colon biopsy and were tested for CMV during 1990 to 2013. After inclusion and exclusion, 41 UC patients were selected. Among them, 24 (58.5%) received treatment, 17 (41.5%) did not. A total of 14 demographic data and 4 clinical outcomes (surgery free survival, hospitalization, rehospitalization, and mortality) were compared between treated and nontreated patients. The same outcomes were also compared in patients who received treatment based on their viremia status.

RESULTS

All demographic variables are similar between those treated and nontreated groups. Antiviral therapy significantly improved the surgery free survival within 30 days, and lasted 70 months (P<0.01). In contrast, hospitalization, rehospitalization, and mortality were comparable (P>0.05). No significant difference was observed in any of the clinical outcomes based on viremia status.

CONCLUSIONS

Our small scale study demonstrates that antiviral treatment for colonic CMV infection significantly improves the surgery free survival short-term and long-term in patients with UC.

Successful and Maladaptive T Cell Aging

Throughout life, the T cell system adapts to shifting resources and demands, resulting in a fundamentally restructured immune system in older individuals. Here we review the cellular and molecular features of an aged immune system and discuss the trade-offs inherent to these adaptive mechanisms. Processes include homeostatic proliferation that maintains compartment size at the expense of partial loss in stemness and incomplete differentiation and the activation of negative regulatory programs, which constrain effector T cell expansion and prevent increasing oligoclonality but also interfere with memory cell generation. We propose that immune failure occurs when adaptive strategies developed by the aging T cell system fail and also discuss how, in some settings, the programs associated with T cell aging culminates in a maladaptive response that directly contributes to chronic inflammatory disease.

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.

ACSS2-mediated acetyl-CoA synthesis from acetate is necessary for human cytomegalovirus infection

Recent studies have shown that human cytomegalovirus (HCMV) can induce a robust increase in lipid synthesis which is critical for the success of infection. In mammalian cells the central precursor for lipid biosynthesis, cytosolic acetyl CoA (Ac-CoA), is produced by ATP-citrate lyase (ACLY) from mitochondria-derived citrate or by acetyl-CoA synthetase short-chain family member 2 (ACSS2) from acetate. It has been reported that ACLY is the primary enzyme involved in making cytosolic Ac-CoA in cells with abundant nutrients. However, using CRISPR/Cas9 technology, we have shown that ACLY is not essential for HCMV growth and virally induced lipogenesis. Instead, we found that in HCMV-infected cells glucose carbon can be used for lipid synthesis by both ACLY and ACSS2 reactions. Further, the ACSS2 reaction can compensate for the loss of ACLY. However, in ACSS2-KO human fibroblasts both HCMV-induced lipogenesis from glucose and viral growth were sharply reduced. This reduction suggests that glucose-derived acetate is being used to synthesize cytosolic Ac-CoA by ACSS2. Previous studies have not established a mechanism for the production of acetate directly from glucose metabolism. Here we show that HCMV-infected cells produce more glucose-derived pyruvate, which can be converted to acetate through a nonenzymatic mechanism.

Bioactive Nutrients and Nutrigenomics in Age-Related Diseases

The increased life expectancy and the expansion of the elderly population are stimulating research into aging. Aging may be viewed as a multifactorial process that results from the interaction of genetic and environmental factors, which include lifestyle. Human molecular processes are influenced by physiological pathways as well as exogenous factors, which include the diet. Dietary components have substantive effects on metabolic health; for instance, bioactive molecules capable of selectively modulating specific metabolic pathways affect the development/progression of cardiovascular and neoplastic disease. As bioactive nutrients are increasingly identified, their clinical and molecular chemopreventive effects are being characterized and systematic analyses encompassing the "omics" technologies (transcriptomics, proteomics and metabolomics) are being conducted to explore their action. The evolving field of molecular pathological epidemiology has unique strength to investigate the effects of dietary and lifestyle exposure on clinical outcomes. The mounting body of knowledge regarding diet-related health status and disease risk is expected to lead in the near future to the development of improved diagnostic procedures and therapeutic strategies targeting processes relevant to nutrition. The state of the art of aging and nutrigenomics research and the molecular mechanisms underlying the beneficial effects of bioactive nutrients on the main aging-related disorders are reviewed herein.

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.

Sociodemographic factors associated with IgG and IgM seroprevalence for human cytomegalovirus infection in adult populations of Pakistan: a seroprevalence survey

Background

The seroprevalence of human cytomegalovirus (HCMV) infection ranges from 30 to 90 % in developed countries. Reliable estimates of HCMV seroprevalence are not available for Pakistan. This study determined the seroprevalence and sociodemographic factors associated with HCMV infection in adult populations of Karachi, Pakistan.

Methods

A seroprevalence survey was conducted on 1000 adults, including residents of two semi-urban communities, and visitors to a government and a private hospital. Questionnaire-based interviews were conducted. Sera were analysed for HCMV-specific IgG and IgM. Chi-square or Fisher’s exact test was used for comparing sociodemographic variables against seropositivity of HCMV-IgG or IgM. Multiple logistic regression modeling was performed for IgG seroprevalence and adjusted odds ratios were computed.

Results

The seroprevalence of HCMV-IgG and IgM was 93.2 and 4.3 % respectively. 95.3 % of individuals who were IgM seropositive were also seropositive for IgG. Around 6 % (15/250) of women of childbearing age remained uninfected and were therefore susceptible to primary infection. HCMV-IgG seroprevalence was associated with being female (p = 0.001), increasing age (p = 0.002) and crowding index (p = 0.003) and also with lower levels of both education (p < 0.001) and income (p = 0.008). Seroprevalence also differed significantly by marital status (p = 0.008) and sampling location (p < 0.001). A logistic regression model for HCMV-IgG seroprevalence showed associations with being female (OR = 1.89; 95 % CI: 1.10–3.25), increasing age (OR = 3.95; 95 % CI: 1.79–8.71) and decreasing income (OR = 0.72; 95 % CI: 0.54–0.96). A strong association was observed between increased seroprevalence of HCMV-IgM and decreasing household size (p = 0.008).

Conclusions

Seroprevalence of HCMV is very high in Pakistan, although 6 % of women of childbearing age remain at risk of primary infection. The IgM seropositivity observed in some individuals living in small household size (1–3 individuals) with persistent HCMV infection could have resulted from a recurrent HCMV infection. Future longitudinal research in pregnant women and neonates is required to study the trends in HCMV seroprevalence over time in Pakistan for the development of a potential HCMV prevention and vaccination programme.

CD28 positive, cytomegalovirus specific cytotoxic T lymphocytes as a novel biomarker associated with cytomegalovirus viremia in kidney allorecipients

BACKGROUND

CMV infection remains major complication after kidney transplantation, thus diagnostics tools that would improve identification of individuals at risk of development of CMV - related complications are useful. For this reason, searching for proper immunological biomarkers candidates gives hope to individualize antiviral therapy and minimize side effects of antiviral drugs.

OBJECTIVES

The purpose of this research was to assess immune assays that can be used to predict the likelihood of CMV viremia after kidney allotransplantation.

STUDY DESIGN

In the study, immunological markers of CMV viremia were assessed in 52 kidney transplant recipients during two years lasting follow-up. Immunological markers associated with viral infection, like lymphocytosis, cytotoxic T lymphocytes (CTL) and serum cytokines levels were compared with less common immunological assays, like activated T lymphocytes, CMV-specific CTL stratified according to naïve/memory phenotype. The test to assess expression of CD28 antigen on CTL, as a possible additional marker of CMV-specificity, was developed.

RESULTS

CD28-positive CMV-specific CTL have been found the most useful marker for CMV viremia prediction. Tested value of 3 cells/μl was found to be most suitable for CMV activation assessment with acceptable sensitivity and specificity.

DISCUSSION

This preliminary report suggests that CD28-positive CMV-specific CTL could be put at the first line, as possible novel marker associated with CMV viremia development.

Cytomegalovirus Colitis and Subsequent New Diagnosis of Inflammatory Bowel Disease in an Immunocompetent Host: A Case Study and Literature Review

Patient: Male, 40

Final Diagnosis: CMV colitis

Symptoms: Abdominal pain • diarrhea • jaundice

Medication: —

Clinical Procedure: Flexible sigmoidoscopy • colonoscopy

Specialty: Family Medicine

Treatment and prevention of cytomegalovirus infection in heart and lung transplantation: an update

INTRODUCTION

Heart and lung transplantation are standard therapeutic strategies to improve survival and quality of life in selected patients with end-stage heart or lung diseases. Cytomegalovirus (CMV) is one the most clinically relevant and frequent post-transplant infectious agents, which may cause direct acute syndromes, and chronic indirect graft-related injury. Despite effective antiviral drugs being available to prevent and treat CMV infection, due to the immunosuppression burden and the specific characteristics of thoracic grafts, CMV infection remains a major clinical problem in heart and lung transplant recipients.

AREAS COVERED

We performed an extensive literature search focused on studies specifically including heart or lung transplantation, when available, or kidney transplant recipients when data on thoracic transplants were not available. We discuss the pros and cons supporting the use of currently available drugs and strategies for CMV prevention and treatment, highlighting current unmet needs.

EXPERT OPINION

While (Val)Ganciclovir remains the cornerstone of anti-CMV therapy, prolonged universal prophylaxis may expose a large number of patients to an excess of drug toxicity. Additional drugs with lower toxicity may be available in the context of anti-CMV prophylaxis, and effective CMV-risk stratification, by means of novel immune monitoring assays, which may help to customize the therapeutic approach.

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.

The Immunology of Posttransplant CMV Infection: Potential Effect of CMV Immunoglobulins on Distinct Components of the Immune Response to CMV

The immune response to cytomegalovirus (CMV) infection is highly complex, including humoral, cellular, innate, and adaptive immune responses. Detection of CMV by the innate immune system triggers production of type I IFNs and inflammatory cytokines which initiate cellular and humoral responses that are critical during the early viremic phase of CMV infection. Sustained control of CMV infection is largely accounted for by cellular immunity, involving various T-cell and B-cell subsets. In solid organ transplant patients, global suppression of innate and adaptive immunities by immunosuppressive agents limits immunological defense, including inhibition of natural killer cell activity with ongoing lowering of Ig levels and CMV-specific antibody titers. This is coupled with a short-term suppression of CMV-specific T cells, the extent and duration of which can predict risk of progression to CMV viremia. CMV immunoglobulin (CMVIG) preparations have the potential to exert immunomodulatory effects as well as providing passive immunization. Specific CMVIG antibodies and virus neutralization might be enhanced by modulation of dendritic cell activity and by a decrease in T-cell activation, effects which are of importance during the initial phase of infection. In summary, the role of CMVIG in reconstituting specific anti-CMV antibodies may be enhanced by some degree of modulation of the innate and adaptive immune responses, which could help to control some of the direct and indirect effects of CMV infection.

Infections and Chronic Inflammatory Bowel Disease

In the more recent years since the introduction of anti-TNF therapy, the treatment strategy in chronic inflammatory bowel disease has developed more towards an early intensive, often double immunosuppression. While this leads to an improved therapeutic success, this intensified therapy also increases the risk for side effects and especially for infectious complications. The early detection of this complication in the immunocompromised patient is often more difficult due to the potential broad spectrum of infectious agents, the often atypical presentation in conjunction with the immunosuppression as well as often similar symptoms regarding intestinal infectious complications common for a flare of the underlying disease. In the first part, this overview will discuss the broad spectrum of potential infectious complications, using pulmonary infections as an example and presenting an algorithm for detection and therapy. In the second part, common intestinal infectious complications will be discussed from diagnosis to therapy.

A novel flow cytometry-based tool for determining the efficiency of human cytomegalovirus infection in THP-1 derived macrophages

Human cytomegalovirus (hCMV) is a ubiquitous pathogen that causes congenital infection and severe infections in immunocompromised patients. Chronic hCMV infection may also play an important role in immunosenescence and adverse health outcomes in older adults. THP-1, a human monocytic cell line and its derived macrophages serve as a useful cell culture model for mechanistic studies of hCMV infection and its underlying biology. A major methodological challenge is the lack of a quick and reliable tool to accurately determine the efficiency of hCMV infection in THP-1 derived macrophages. In this study, we developed a flow cytometry based method using commercially available monoclonal antibody (MAb) against hCMV immediate early (IE) antigen that can accurately determine infection efficiency. We used 0.5% formaldehyde for fixation, 90% methanol for permeabilization, and incubation with FITC conjugated MAb at 37°C. The method was tested by hCMV infection with laboratory Towne strain in the presence or absence of hydrocortisone. It was also compared with the routine flow cytometry protocol using Cytofix/Cytoperm solution and with immunofluorescence. The results indicate that this new method is reliable and time saving for accurate determination of infection efficiency. It may facilitate further investigations into the underlying biological mechanisms of hCMV infection.

Induction of cytomegalovirus-specific T cell responses in healthy volunteers and allogeneic stem cell recipients using vaccination with messenger RNA-transfected dendritic cells

Background

Infection with human cytomegalovirus (CMV) is a significant cause of morbidity and mortality in solid organ and hematopoietic stem cell transplant (HSCT) recipients.

Methods

The present study explored the safety, feasibility, and immunogenicity of CMV pp65 messenger RNA–loaded autologous monocyte-derived dendritic cells (DC) as a cellular vaccine for active immunization in healthy volunteers and allogeneic HSCT recipients. Four CMV-seronegative healthy volunteers and three allogeneic HSCT recipients were included in the study. Four clinical-grade autologous monocyte-derived DC vaccines were prepared after a single leukapheresis procedure and administered intradermally at a weekly interval.

Results

De novo induction of CMV-specific T-cell responses was detected in three of four healthy volunteers without serious adverse events. Of the HSCT recipients, none developed CMV disease and one of two patients displayed a remarkable threefold increase in CMV pp65-specific T cells on completion of the DC vaccination trial.

Conclusion

In conclusion, our DC vaccination strategy induced or expanded a CMV-specific cellular response in four of six efficacy-evaluable study subjects, providing a base for its further exploration in larger cohorts.

Supplemental digital content is available in the text.

Human cytomegalovirus infection is associated with essential hypertension in Kazakh and Han Chinese populations

Background

We aimed to study the association between cytomegalovirus (CMV) infection and hypertension in Kazakh and Han populations from Xinjiang Province, China.

Material/Methods

We analyzed data on 800 Kazakhs (467 hypertension patients and 333 healthy control participants) and 800 Hans (482 hypertension patients and 318 healthy control participants) aged 18–84 years old. ELISA and real-time quantitative PCR coupled with restriction fragment length polymorphism analysis were applied for determining CMV infection and glycoprotein B (gB) genotypes, respectively.

Results

Serologic evidence of CMV infection was obtained for 95.4% and 90.1% of the Kazakhs and Hans, respectively. The CMV seroprevalence rates among the Kazakh and Han participants with hypertension were 96.8% and 89.8%, respectively. Multiple logistic regression analyses revealed statistically significant independent associations between CMV seropositivity and hypertension in Kazakh males and between CMV antibody titers and hypertension in Hans; significant relationships also existed between CMV antibody titers and blood pressure in Hans. In Kazakhs, 3 CMV gB genotypes were identified: gB2 and genotype mixtures gB1+gB2 and gB2+gB3. In Hans, 4 CMV gB genotypes were identified: gB1, gB2, gB1+gB2, and gB2+gB3. Of the 4 studied genotypes, gB2+gB3 showed a significant independent association with hypertension in Kazakh females.

Conclusions

CMV infection is associated with essential hypertension in Kazakh males and Hans in Xinjiang. CMV seropositivity is associated with hypertension in Kazakh males, and CMV antibody titers are associated with blood pressure and hypertension in Han males and females. Moreover, the CMV gB2+gB3 genotype mixture is associated independently with essential hypertension in Kazakh females.

Cytomegalovirus infection in inflammatory bowel disease is not associated with worsening of intestinal inflammatory activity

Background

Cytomegalovirus is highly prevalent virus and usually occurs in immunocompromised patients. The pathophysiology and treatment of inflammatory bowel disease often induce a state of immunosuppression. Because this, there are still doubts and controversies about the relationship between inflammatory bowel disease and cytomegalovirus.

Aim

Evaluate the frequency of cytomegalovirus in patients with inflammatory bowel disease and identify correlations.

Methods

Patients with inflammatory bowel disease underwent an interview, review of records and collection of blood and fecal samples. The search for cytomegalovirus was performed by IgG and IgM blood serology, by real-time PCR in the blood and by qualitative PCR in feces. Results were correlated with red blood cell levels, C-reactive protein levels, erythrocyte sedimentation rates and fecal calprotectin levels for each patient.

Results

Among the 400 eligible patients, 249 had Crohn's disease, and 151 had ulcerative colitis. In the group of Crohn's disease, 67 of the patients had moderate or severe disease, but 126 patients presented with active disease, based on the evaluation of the fecal calprotectin. In patients with ulcerative colitis, only 21 patients had moderate disease, but 76 patients presented with active disease, based on the evaluation of the fecal calprotectin. A large majority of patients had positive CMV IgG. Overall, 10 patients had positive CMV IgM, and 9 patients had a positive qualitative detection of CMV DNA by PCR in the feces. All 400 patients returned negative results after the quantitative detection of CMV DNA in blood by real-time PCR. Analyzing the 19 patients with active infections, we only found that such an association occurred with the use of combined therapy (anti-TNF-alpha + azathioprine)

Conclusion

The findings show that latent cytomegalovirus infections are frequent and active cytomegalovirus infection is rare. We did not find any association between an active infection of CMV and inflammatory bowel disease activity.

Delayed-onset cytomegalovirus disease coded during hospital readmission after kidney transplantation

BACKGROUND

Use of prophylactic anti-CMV therapy for 3 to 6 months after kidney transplantation can result in delayed-onset CMV disease. We hypothesized that delayed-onset CMV disease (occurring >100 days posttransplant) occurs more commonly than early-onset CMV disease and that it is associated with death.

METHODS

We assembled a retrospective cohort of 15,848 adult kidney transplant recipients using 2004 to 2010 administrative data from the California and Florida Healthcare Cost and Utilization Project State Inpatient Databases. We identified demographic data, comorbidities, CMV disease coded during readmission, and inpatient death. We used multivariate Cox proportional hazards modeling to determine risk factors for delayed-onset CMV disease and inpatient death.

RESULTS

Delayed-onset CMV disease was identified in 4.0%, and early-onset CMV disease was identified in 1.2% of the kidney transplant recipients. Risk factors for delayed-onset CMV disease included previous transplant failure or rejection (HR 1.4) and residence in the lowest-income ZIP codes (HR 1.2). Inpatient death was associated with CMV disease occurring 101 to 365 days posttransplant (HR 1.5), CMV disease occurring greater than 365 days posttransplant (HR 2.1), increasing age (by decade: HR 1.5), nonwhite race (HR 1.2), residence in the lowest-income ZIP codes (HR 1.2), transplant failure or rejection (HR 3.2), previous solid organ transplant (HR 1.7), and several comorbidities.

CONCLUSION

These data showed that delayed-onset CMV disease occurred more commonly than early-onset CMV disease and that transplant failure or rejection is a risk factor for delayed-onset CMV disease. Further research should be done to determine if delayed-onset CMV disease is independently associated with death.

Latent infection of human cytomegalovirus is associated with the development of gastric cancer

The worldwide contagion, human cytomegalovirus (HCMV), may cause a series of disorders in infected individuals. The aim of the present study was to investigate whether HCMV infection is associated with the development of gastric cancer. In this study, the positive expression of unique long (UL)133-UL138 and immediate-early (IE)1 genes, which are associated with viral latency and replication, respectively, were detected using nested polymerase chain reaction. A χ2 test and logistic regression analysis were performed to further investigate the preliminary data. The data indicated that the positive rate of UL133, UL135 and UL136 expression in cancer tissues was higher than that in paired normal tissues (P=0.01, 0.027 and 0.013, respectively). However, no significant differences were identified in the UL133-138 locus and IE1 gene when associated with clinicopathological features. Furthermore, seven infection patterns were identified, with the UL133 + UL138 infection pattern representing the largest proportion in the cancer (60.34%) and normal tissues (42.11%). In conclusion, it is possible that the UL133-UL138 locus is important in the occurrence of gastric cancer. The mechanism by which UL133-UL138 locus expression differs in human gastric cancer requires further investigation.

Immune-based monitoring for cytomegalovirus infection in solid organ transplantation: is it ready for clinical primetime?

The impact of CMV infection and disease in solid organ transplant (SOT) recipients continues despite remarkable improvements in its prevention and management with antiviral drugs. Studies that have investigated the host immune response to CMV have paved way for the development of novel immune-based assays that are anticipated to complement the current antiviral-based strategies for CMV management after transplantation. In this article, we review the emerging data on the clinical application of innovative CMV-specific T-cell assays, including their role in risk-stratification, prognostication, prevention and treatment of CMV infection and disease in SOT recipients.

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

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

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

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

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

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.

Looking for endoscopic features of cytomegalovirus colitis: a study of 187 patients with active ulcerative colitis, positive and negative for cytomegalovirus

BACKGROUND

Cytomegalovirus (CMV) is frequently detected in ulcerative colitis (UC) lesions of steroid-refractory patients. This has led to the suspicion that CMV might cause colitis and steroid refractoriness.

METHODS

During 2003 and 2011, 187 consecutive patients were divided into group I (n = 105), corticosteroid-free and thiopurine-free in the past 6 months, and group II (n = 82), all corticosteroid refractory. The combination of serum CMV immunoglobulin (Ig)M, CMV IgG, CMV antigenemia (Ag), and real-time polymerase chain reaction assays were performed to identify CMV(+) patients.

RESULTS

In group I, 79 patients were CMV IgG(+) and 26 patients were CMV IgG(-) and CMV IgM(-). In group II, 61 patients were CMV IgG(+), 1 CMV IgM(+), and 20 CMV IgG(-) and CMV IgM(-). All CMV IgG(+) patients were screened for CMV Ag. In group I, 6 of the 79 CMV IgG(+) patients were CMV Ag(+). In group II, 27 patients were CMV Ag(+). Colonoscopy was performed in all patients before screening for CMV. Similar colonoscopic features including punched out ulcers, geographic ulcers, and irregular ulcers were found in both CMV(+) and CMV(-) patients, without any striking difference between the 2 groups.

CONCLUSIONS

CMV reactivation might be encouraged by immunosuppressive drugs, like corticosteroids, immunomodulators, and therefore, patients with UC are at a high risk of CMV reactivation, potentially exacerbating UC. However, this study of 187 patients, CMV(+) and CMV(-), could not find colonoscopic features unique to CMV, except that CMV might be one factor for steroid refractoriness, and UC exacerbation.

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.

HLA-E-restricted cross-recognition of allogeneic endothelial cells by CMV-associated CD8 T cells: a potential risk factor following transplantation

Although association between CMV infection and allograft rejection is well admitted, the precise mechanisms involved remain uncertain. Here, we report the characterization of an alloreactive HLA-E-restricted CD8 T cell population that was detected in the PBL of a kidney transplant patient after its CMV conversion. This monoclonal CD8 T cell population represents a sizable fraction in the blood (3% of PBL) and is characterized by an effector-memory phenotype and the expression of multiple NK receptors. Interestingly, these unconventional T cells display HLA-E-dependent reactivity against peptides derived from the leader sequences of both various HCMV-UL40 and allogeneic classical HLA-I molecules. Consequently, while HLA-E-restricted CD8 T cells have potential to contribute to the control of CMV infection in vivo, they may also directly mediate graft rejection through recognition of peptides derived from allogeneic HLA-I molecules on graft cells. Therefore, as HLA-E expression in nonlymphoid organs is mainly restricted to endothelial cells, we investigated the reactivity of this HLA-E-restricted T cell population towards allogeneic endothelial cells. We clearly demonstrated that CMV-associated HLA-E-restricted T cells efficiently recognized and killed allogeneic endothelial cells in vitro. Moreover, our data indicate that this alloreactivity is tightly regulated by NK receptors, especially by inhibitory KIR2DL2 that strongly prevents TCR-induced activation through recognition of HLA-C molecules. Hence, a better evaluation of the role of CMV-associated HLA-E-restricted T cells in transplantation and of the impact of HLA-genotype, especially HLA-C, on their alloreactivity may determine whether they indeed represent a risk factor following organ transplantation.