Assessment of CMV load in solid organ transplant recipients by pp65 antigenemia and real-time quantitative DNA PCR assay: Correlation with pp67 RNA detection

Advances and Challenges in Cytomegalovirus Detection Methods for Liver Transplant Donors

Cytomegalovirus (CMV) infection is a highly prevalent opportunistic infection among liver transplant recipients. When the liver donor is infected with CMV, there is a risk of transmission to the recipient, leading to CMV infection. To improve the postoperative outcome of liver transplantation, it is crucial to shift the focus of CMV detection to the donor and achieve early diagnosis, as well as implement effective preventative and therapeutic measures. However, the commonly used CMV detection methods in the past had limitations that prevented their early and accurate diagnosis in liver transplant donors. This review focuses on the latest advancements in CMV detection methods that can potentially be applied to liver transplant donors. The objective is to compare and evaluate their clinical utility, thereby providing guidance and support for rapid and accurate diagnosis of CMV infection in the clinic. The clustered regularly interspaced short palindromic repeats-associated proteins (CRISPR-Cas) system-based assay emerges as a promising method for detecting the virus, offering great prospects for early and expedient CMV infection diagnosis in clinical settings.

A Systematic Review and Meta-analysis of Optimized CMV Preemptive Therapy and Antiviral Prophylaxis for CMV Disease Prevention in CMV High-Risk (D+R-) Kidney Transplant Recipients

The optimal strategy for cytomegalovirus (CMV) disease prevention in CMV donor/recipient kidney transplant recipients remains uncertain. Conclusions of prior meta-analyses that CMV disease rates with preemptive therapy (PET) and universal prophylaxis (UP) were comparable may have been affected by inclusion of studies lacking key determinants of efficacy of the respective strategies.

Methods

We conducted a systematic review and meta-analysis of PET with weekly CMV polymerase chain reaction monitoring for ≥3 mo and UP with 6 mo of valganciclovir. PubMed and Embase databases were reviewed from January 1, 2010, to April 1, 2022. Risk of bias was assessed with 3 instruments (Cochrane RoB, Cochrane RoBINS-I, and an instrument for assessing risk in observational studies). The primary outcome was CMV disease incidence by 1-y posttransplant. Secondary outcomes by 1-y were graft loss, acute allograft rejection, and mortality. Results were synthesized using generalized linear mixed model meta-analysis. PET studies were stratified into low-threshold (LT) and high-threshold (HT) PET based on the viral load threshold for initiation of antiviral therapy.

Results

Twenty-five studies met inclusion criteria (6 PET, 19 UP). CMV disease incidence was significantly higher in HT (0.30 [95% confidence interval (CI), 0.22-0.39]) versus LT PET (0.06 [95% CI, 0.03-0.12]). LT PET was associated with a significantly lower CMV disease incidence (0.06 [95% CI, 0.03-0.12]) versus UP (0.21 [95% CI, 0.17-0.27]). Incidence of graft loss, acute allograft rejection, or mortality was not significantly different between LT PET and UP (P > 0.05 for all comparisons). Receipt of lymphocyte-depleting antibodies was not associated with a significant difference in CMV disease incidence (odds ratio = 1.34 [95% CI, 0.80-2.25]).

Conclusions

LT PET is associated with a significantly lower incidence of CMV disease compared to UP with similar rates of other clinical outcomes. These findings provide rationale and preliminary data for a randomized superiority trial of optimized LT-PET versus UP in donor seropositive recipient seronegative kidney transplant recipients.

Human cytomegalovirus and Epstein-Barr virus infections occurring early after transplantation are risk factors for antibody-mediated rejection in heart transplant recipients

Background

Antibody-mediated rejection (AMR) is a serious complication affecting the survival of patients receiving transplantation. Human cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are common viral infections that occur after transplantation, frequently emerging as viral reactivation in donor grafts or transplant recipients. The present study aimed to investigate the association between CMV and EBV infections and early-onset AMR.

Materials and methods

This study was conducted at the Heart Transplantation Center of Padova General Hospital and included a cohort of 47 heart transplant recipients (HTxs), including 24 HTxs diagnosed with AMR and 23 control HTxs with no episodes of AMR. Only early cases of CMV and/or EBV infections (1-90 days after transplantation) were considered. Fisher's exact test and logistic regression analysis were used to statistically analyze the correlation and association between AMR and CMV or EBV infection.

Results

We observed a positive statistical association between CMV and EBV infections (two-sided Fisher's exact test, p = 0.0136) and between EBV infection and AMR (two-sided Fisher's exact test, p = 0.0034). Logistic regression analysis revealed a direct statistical association between CMV and EBV infections and AMR risk (p = 0.037 and 0.006 and odds ratio = 1.72 and 2.19, respectively). AMR occurrence was associated with increased viral loads of both CMV and EBV early after transplantation.

Discussion

These findings suggest the role of CMV and EBV infections as relevant risk factors for AMR in HTxs for the first time.

Urinary Tract Infections: Virus

Although viruses are common in the urinary tract in healthy people, viral infections can become a major concern in immunocompromised individuals. Patients undergoing hematopoietic stem cell or solid organ transplantation may be particularly susceptible to BK and other viruses, and experience a high risk of mortality. The most common presentation in this setting is hemorrhagic cystitis. The treatment is mostly supportive, including the reduction of immunosuppression; a variety of experimental agents has also been proposed. A different context is offered by chronic (HBV, HCV, HIV) or acute/subacute (Dengue, Hantavirus, etc.) infections, where the kidneys can be secondarily involved and suffer from several glomerular syndromes. Many protocols based on different oral direct-acting antivirals and combined antiretrovirals are available, according to the systemic infection. Viral infections can be classified according to the organ involved, i.e. lower (bladder) or upper urinary tract (kidneys, ureters), and to the mechanism of injury. A section is dedicated to the current breakout of SARS-CoV-2, which does not spare the urinary tract, sometimes with serious implications. Even if this topic is mostly the discipline of ultra-dedicated physicians, this overview has a practical approach and could be useful to a wider medical audience, especially in times of viral pandemics.

Prevention and management of human cytomegalovirus in pediatric HSCT recipients: A review

Cytomegalovirus (CMV), like other herpesviruses, has the unique ability to establish latent infection with subsequent reactivation during periods of stress and immunosuppression. Herpesviruses cause potentially devastating disease, particularly in hematopoietic stem cell transplant (HSCT) recipients. CMV is especially of concern in HSCT recipients given the high community seroprevalence, high risk of reactivation and high risk of transmission from HSCT donors to recipients causing primary infection after transplantation. The risk of CMV infection and severity of CMV disease varies depending on the underlying disease of the HSCT recipient, donor and recipient CMV status prior to HSCT, type of conditioning therapy in preparation for HSCT, allogeneic versus autologous HSCT, donor graft source, timing of infection in relation to HSCT, and other patient comorbidities. Different strategies exist for prevention (e.g., preemptive therapy vs. universal prophylaxis) as well as management of CMV disease (e.g., antiviral therapy, augmenting immune reconstitution, cytotoxic T-cell therapy). The purpose of this narrative review is to discuss diagnosis, prevention, and management of CMV infection and disease at different stages of HSCT, including key points illustrated through presentations of complex cases and difficult clinical scenarios. Traditional and novel strategies for CMV management will be discussed in the context of these unique clinical cases.

Cytomegalovirus, Epstein-Barr virus and human herpesvirus 8 salivary shedding in HIV positive men who have sex with men with controlled and uncontrolled plasma HIV viremia: a 24-month longitudinal study

Background

This longitudinal study described Cytomegalovirus (CMV) DNA, Epstein-Barr (EBV) DNA and human herpesvirus 8 (HHV-8) DNA asymptomatic salivary shedding in HIV-positive men who have sex with men (MSM). We aimed to 1-analyze frequency and persistence of herpesvirus shedding, 2-correlate herpesvirus positivity and HIV viroimmunological parameters and 3-assess the association between HIV-RNA suppression and herpesvirus replication.

Methods

Herpesvirus DNA was tested with an in-house real-time PCR in 2 salivary samples obtained at T0 and T1 (24 months after T0). HIV-RNA was evaluated in the 24 months prior to T0 and in the 24 months prior to T1; MSM were classified as successfully suppressed patients (SSPs), viremic patients (VPs) and partially suppressed patients (PSPs). EBV DNA load was classified as low viral load (EBV-LVL, value ≤10,000 copies/ml) and as high viral load (EBV-HVL,> 10,000 copies/ml). Mann-Whitney U test tested the difference of the median between groups of patients. Chi-squared test and Fisher’s exact test compared categorical variables according to the frequencies. Kruskal-Wallis test compared continuous data distributions between levels of categorical variables.

Results

Ninety-two patients (median CD4+ count 575 cells/mm3, median nadir 330 CD4+ cells/mm3) were included: 40 SSPs,33 VPs and 19 PSPs. The more frequently single virus detected was EBV, both at T0 and at T1 (in 67.5 and 70% of SSPs, in 84.8 and 81.8% of VPs and in 68.4 and 73.7% of SPSs) and the most frequently multiple positivity detected was EBV + HHV-8. At T1, the percentage of CMV positivity was higher in VPs than in SSPs (36.4% vs 5%, p < 0.001), the combined shedding of HHV-8, CMV and EBV was present only in VPs (15.1%, p = 0.01 respect to SSPs) and no VPs confirmed the absence of shedding found at T0 (vs 17.5% of SSPs, p = 0.01). EBV-HVL was more frequent in VPs than in SSPs: 78.6% at T0 (p = 0.03) and 88.9% at T1 (p = 0.01).

Conclusions

The relationship between uncontrolled plasma HIV viremia and CMV, EBV, and HHV-8 shedding is multifaceted, as demonstrated by the focused association with EBV DNA load and not with its frequency and by the persistent combined detection of two oncogenic viruses as EBV and HHV-8 regardless of HIV virological control.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3591-x) contains supplementary material, which is available to authorized users.

Cytomegalovirus

Cytomegalovirus (CMV), the largest of the herpesviruses, causes a wide range of clinical syndromes, from asymptomatic infection to severe disease in immunocompromised hosts. Laboratory methods for diagnosis include molecular testing, antigenemia, culture, serology, and histopathology. Treatment of CMV infection and disease is indicated in selected immunocompromised hosts, and preventive approaches are indicated in high-risk groups. This chapter reviews the epidemiology, clinical aspects, and the laboratory diagnosis and management of CMV in immunocompromised hosts.

Diagnostic Accuracy of Blood-Based Tests and Histopathology for Cytomegalovirus Reactivation in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

It is unclear if traditional histopathology and noninvasive blood-based tests are sufficiently accurate to detect cytomegalovirus (CMV) reactivation in inflammatory bowel disease. Therefore, we assessed the diagnostic accuracy of these tests compared with immunohistochemistry (IHC) and tissue polymerase chain reaction (PCR).

METHODS

A systematic search of electronic databases was performed from inception through January 2016 for observational studies comparing diagnostic tests for CMV reactivation in inflammatory bowel disease. IHC and tissue PCR were considered reference standards and were used to evaluate the accuracy of blood-based tests and hematoxylin and eosin histopathology. Weighted summary estimates with 95% confidence intervals (CIs) were calculated using bivariate analysis.

RESULTS

Nine studies examined the accuracy of blood-based tests for predicting colonic CMV reactivation: 5 studies by pp65 antigenemia and 4 studies by blood PCR. The overall sensitivity was 50.8% (95% CI, 19.9-81.6), the specificity was 99.9% (95% CI, 99-100), and the positive predictive value was 83.8% (95% CI, 58.6-95.0). The sensitivities of pp65 and blood PCR were 39.7% (95% CI, 27.4-52.1) and 60.0% (95% CI, 46.5-73.5), respectively. Nine studies examined the sensitivity of histopathology. The overall sensitivity was 12.5% (95% CI, 3.6-21.4), 34.6% by IHC (95% CI, 13.8-55.4), and 4.7% by tissue PCR (95% CI, 1.2-17.1).

CONCLUSIONS

Although blood-based tests seem to predict colonic CMV reactivation, they are insensitive tests. Similarly, histopathology has poor sensitivity for detecting colonic CMV. In agreement with current guidelines, these tests should not replace IHC or tissue PCR for detecting CMV reactivation in inflammatory bowel disease.

Virological testing of cerebrospinal fluid in children aged less than 14 years with a suspected central nervous system infection: A retrospective study on 304 consecutive children from January 2012 to May 2015

OBJECTIVE

The study aimed to describe the prevalence of HSV DNA, VZV DNA, Enterovirus RNA, Parechovirus RNA, CMV DNA, EBV DNA, adenovirus DNA, HHV-6 DNA, HHV-7 DNA, HHV-8 DNA and Parvovirus B19DNA in children aged less 14 years with a suspected viral infection of the central nervous system in a clinical practice setting.

METHODS

Between January 2012 and May 2015, cerebrospinal fluids from 304 children were tested with an in-house real-time PCR method.

RESULTS

A positive PCR was detected in 64 subjects (21%): the mean number of tests performed in patients who showed a viral infection was 7.5, significantly higher (p = 0.001) with respect to that reported in negative samples (6.4). Enterovirus is the leading virus detected: 12 out of the 37 positive children reported were newborns (85.7% of all the newborns with a positive result). The second most frequently identified virus was HHV-7 (5 positive PCR out of 105 samples tested, 4.8%, if we excluded a child with a concomitant S. pneumoniae isolated), a prevalence significantly higher with respect to VZV (p = 0.02) and to CMV (p = 0.04). HHV-6 was the third most commonly identified aetiology (4.2%). All children were immunocompetent.

SIGNIFICANCE

Only a minority of children had a specific viral aetiology identified: the rate of HHV-7 positivity suggests a routine testing of these viruses within the diagnostic algorithm in immunocompetent paediatric patients. This approach could help to define the clinical role of this herpesvirus.

Cytomegalovirus (CMV) Enzyme-Linked Immunosorbent Spot Assay but Not CMV QuantiFERON Assay Is a Novel Biomarker To Determine Risk of Congenital CMV Infection in Pregnant Women

Cytomegalovirus (CMV) enzyme-linked immunosorbent spot (ELISPOT) and CMV QuantiFERON assays were examined as potential biomarkers predictive of congenital CMV (cCMV) transmission. Fifty-seven pregnant women with primary CMV infection and 23 with nonprimary CMV infection were recruited in the study. Maternal age, CMV IgG avidity, viremia, and viruria were also included among the potential predictors. Spearman's statistical correlation analysis revealed a positive correlation between the CMV ELISPOT and CMV QuantiFERON assay results (P < 0.001), but only the CMV ELISPOT assay correlated with cCMV (P < 0.001). cCMV was positively correlated with maternal viremia and viruria (P < 0.05) and negatively correlated with CMV IgG avidity (P < 0.01). Maternal age and CMV QuantiFERON assay results were not statistically associated with cCMV. CMV-specific cell-mediated immunity detected by the CMV ELISPOT assay plays a critical role in cCMV.

Epstein-Barr and cytomegalovirus DNA salivary shedding correlate with long-term plasma HIV RNA detection in HIV-infected men who have sex with men

The aim of the study was to evaluate cytomegalovirus (CMV) and Epstein-Barr virus (EBV) DNA salivary shedding in HIV-positive men who have sex with men (MSM) and to determine whether viro-immunological parameters and long-term (24 months) plasma HIV RNA (pHIV) detection may predict herpesviruses replication. A total of 193 HIV-positive MSM were consecutively recruited (mean CD4+ cell count 607 cells/mm(3) and mean nadir value 333 cells/mm(3) ); pHIV was analyzed for 24 months prior to saliva sampling: patients were categorized as successfully suppressed (SS) and not suppressed (NS). The EBV viral load was categorized as high viral load (HVL), intermediate (IVL), or low (LVL), CMV DNA as positive or negative. NS patients experienced both herpesviruses detectability more frequently respect to SS patients (P = 0.034); conversely, no salivary shedding was more frequent in SS patients (P = 0.014). HVL EBV was more frequent in NS patients than in SS subjects (P = 0.038 for isolated EBV detection and P = 0.001 when CMV shedding was associated). NS subjects with HVL EBV had a median pHIV of 43,820 copies/ml, significantly higher respect to IVL and LVL patients (P = 0.027 and P = 0.0005, respectively). CMV shedding was mostly associated to EBV shedding. NS patients showed a significantly higher frequency of saliva HVL EBV detection compared to SS patients; moreover, NS patients with HVL EBV had a higher pHIV respect to those with IVL and LVL shedding. Our results suggest that a successful pHIV suppression could reduce the burden of salivary EBV replication and likely the risk of herpesviruses-related cancers.

Strong Cell-Mediated Immune Response to Human Cytomegalovirus Is Associated With Increased Risk of Fetal Infection in Primarily Infected Pregnant Women

BACKGROUND

Human cytomegalovirus (CMV) represents one of the leading causes of congenital infections worldwide. Early diagnosis of fetal infection and consequent rapid therapeutic intervention with immunoglobulin treatment may prevent fetal transmission and virus-related sequelae. In this study, the cell-mediated immunity and immunoglobulin avidity were evaluated as potential predictors of congenital transmission of the infection.

METHODS

CMV immunoglobulin G (IgG) avidity and CMV enzyme-linked immunospot (ELISpot) assays were employed in 80 pregnant women including 57 primary and 23 nonprimary CMV infections. Congenital infection was assessed using CMV DNA quantitative polymerase chain reaction on amniotic fluid or offspring urine. Logistic regression and receiver operating characteristic statistical methods were employed to determine the association with congenital infection.

RESULTS

Low CMV IgG avidity (25%) alone correlated with a probability of congenital transmission of 18.2% (95% confidence interval, 7.7%-28.8%). In contrast to the expectations, an increase in CMV ELISpot levels was statistically associated with congenital transmission (P = .006). The combined use of CMV ELISpot and low CMV IgG avidity resulted in a higher level of association than either method alone with the incidence of fetal transmission (area under the curve, 0.8685).

CONCLUSIONS

CMV-specific cell-mediated immunity represents a relevant marker in assessing the likelihood of congenital CMV transmission, particularly in combination with CMV IgG avidity.

High Cytomegalovirus (CMV) DNAemia Predicts CMV Sequelae in Asymptomatic Congenitally Infected Newborns Born to Women With Primary Infection During Pregnancy

OBJECTIVE

We investigated the kinetics of cytomegalovirus (CMV) clearance in blood and urine and the relationship between the viral load in blood at birth and the development of late-onset sequelae in asymptomatic congenital CMV infection.

METHODS

Thirty-three newborns with congenital asymptomatic CMV infection born to women with primary CMV infection during pregnancy were enrolled. CMV infection was monitored by polymerase chain reaction analysis of blood and urine. The follow-up examination was concluded at 6 years of age.

RESULTS

Ten infants developed postnatal sequelae, whereas twenty-three infants remained asymptomatic. Fifty percent of babies cleared CMV in blood and urine within 3 and 36 months, respectively. Logistic multivariate regression revealed that the risk of neonatal clinical disease crossed the level of 50% with a DNAemia at birth of ≥ 12,000 copies/mL (P = .0002). The risk of hearing deficit crossed the level of 50% with a DNAemia at birth of ≥ 17,000 copies/mL (P = .0001). No significant difference was found between the kinetics of CMV clearance in asymptomatic children as compared to babies with late-onset disease.

CONCLUSIONS

Asymptomatic newborns with a CMV DNAemia at birth of ≥ 12,000 copies/mL were more likely to experience CMV-related sequelae. The risk of hearing deficit increased with a viral load in blood of ≥ 17,000 copies/mL.

Clinical characteristics and therapy exploration of active human cytomegalovirus infection in 105 lupus patients

Systemic lupus erythematosus (SLE) has protean clinical manifestations of varying severity over the course of its onset, exacerbation, remission and flare that could often pose significant challenges for clinicians in their decision making as to whether to treat aggressively or to look for concurrent conditions such as infection with opportunistic pathogens. Human cytomegalovirus (HCMV) is one of those pathogens and is frequently encountered in our daily management of lupus patients. To investigate the clinical characteristics and therapeutic options of active HCMV infection in patients with SLE, we retrospectively reviewed clinical data of 105 inpatients in our department of Rheumatology and Clinical Immunology of Peking Union Medical College Hospital (PUMCH) diagnosed with both SLE and active HCMV infection from January 2006 to January 2012. Three groups were designated that included 42 cases of HCMV triggering SLE, 31 cases of HCMV exacerbating SLE, and 32 cases of HCMV mimicking SLE flare based on the relationship of HCMV infection and SLE. 1) Hematocytopenia (81%), fever (73.3%) and liver dysfunction (54.3%) were the most common clinical manifestations. The differences among the three groups with regard to butterfly erythema, cutaneous vasculitis, arthritis, serositis, central nervous system involvement and renal involvement were statistically significant (p < 0.05). 2) Positive rate of HCMV-pp65, compared with HCMV-IgM and HCMV-DNA, was the highest (84.9%) in patients with SLE and active HCMV infection. 3) Following 14-21 days of inductive treatment with ganciclovir, a total of 26 out of 56 patients were still positive with HCMV-IgM (nine of 19, 47.6%) and pp65 (17/37, 45.9%). Among them, seven cases suffered HCMV relapses in three months with six cases of sustained HCMV-pp65 antigenemia. In conclusion, hematocytopenia, fever and liver dysfunction should remind us to consider HCMV infection. Butterfly erythema, cutaneous vasculitis, arthritis, serositis, central nervous system involvement and renal lesion were relatively characteristic symptoms of lupus activity. HCMV-pp65 is a sensitive indicator to guide antiviral therapy. Induction therapy using ganciclovir with a duration of 14∼21 days is not sufficient, and continued HCMV-pp65 positivity may require prolonged antiviral treatment in lupus patients.

Clinical utility of viral load in management of cytomegalovirus infection after solid organ transplantation

The negative impact of cytomegalovirus (CMV) infection on transplant outcomes warrants efforts toward improving its prevention, diagnosis, and treatment. During the last 2 decades, significant breakthroughs in diagnostic virology have facilitated remarkable improvements in CMV disease management. During this period, CMV nucleic acid amplification testing (NAT) evolved to become one of the most commonly performed tests in clinical virology laboratories. NAT provides a means for rapid and sensitive diagnosis of CMV infection in transplant recipients. Viral quantification also introduced several principles of CMV disease management. Specifically, viral load has been utilized (i) for prognostication of CMV disease, (ii) to guide preemptive therapy, (iii) to assess the efficacy of antiviral treatment, (iv) to guide the duration of treatment, and (v) to indicate the risk of clinical relapse or antiviral drug resistance. However, there remain important limitations that require further optimization, including the interassay variability in viral load reporting, which has limited the generation of standardized viral load thresholds for various clinical indications. The recent introduction of an international reference standard should advance the major goal of uniform viral load reporting and interpretation. However, it has also become apparent that other aspects of NAT should be standardized, including sample selection, nucleic acid extraction, amplification, detection, and calibration, among others. This review article synthesizes the vast amount of information on CMV NAT and provides a timely review of the clinical utility of viral load testing in the management of CMV in solid organ transplant recipients. Current limitations are highlighted, and avenues for further research are suggested to optimize the clinical application of NAT in the management of CMV after transplantation.

Cytomegalovirus colitis in intensive care unit patients: difficulties in clinical diagnosis

PURPOSE

Cytomegalovirus (CMV) infection occurs increasingly in critically ill patients in intensive care units (ICUs). We reported CMV colitis which has rarely been recognized in the ICU patients.

METHODS

CMV DNA was detected by polymerase chain reaction (PCR) for blood and/or stool samples. Definite diagnosis of CMV colitis required histopathology or CMV immunohistochemical staining of colorectal biopsies. We reviewed ICU patients characterized by positive blood or stool CMV-PCR with colorectal bleeding or water diarrhea.

RESULTS

We identified 18 patients (biopsy-proved, n=8; probable cases, n=10). The most common comorbidities were chronic renal disease, diabetes mellitus, and coronary artery disease. Stool CMV-PCR was positive in 7 of 10 patients (2 of 3 biopsy-proved and 5 of 7 probable cases). Colonoscopy was performed for 15 patients, revealing ulcerative or polypoid lesions. The endoscopists obtained colonic biopsies from 9 patients. Yet, the pathologists reported CMV colitis for 4 patients. Additional 4 patients were confirmed using immunohistochemical stain by the request of clinical physicians. Pseudomembranous colitis was found in 4 patients.

CONCLUSION

Diagnosis of CMV colitis seems difficult in clinical practice and need persistent communication between clinicians. The positive stool CMV-PCR result was a useful hint for adding immunohistochemical stain in mucosal biopsies to make a definite diagnosis of CMV colitis.

Recent developments in human cytomegalovirus diagnosis

Since the early 1990s, great efforts have been made in the field of human cytomegalovirus (HCMV) diagnosis. Besides HCMV diagnosis in immunosuppressed patients (solid organ transplant recipients, hematopoietic stem cell transplant patients and AIDS patients), diagnosis in connection with congenital HCMV infection is of great interest. This review focuses on the development and clinical utility of serological assays, as well as on virological tests (molecular and nonmolecular assays). Interpretation of these tests is strongly dependent on the patient group (solid organ transplant recipients and hematopoietic stem cell transplant patients) and whether the tests are used for screening, risk stratification or diagnosis. Furthermore, a better understanding of HCMV infection has led to new approaches in HCMV diagnosis and monitoring. Thus, assays for viral resistance testing and assays for monitoring the HCMV-specific cellular immune response are increasingly important for the guidance of antiviral therapy.

Comparison of cytomegalovirus (CMV) enzyme-linked immunosorbent spot and CMV quantiferon gamma interferon-releasing assays in assessing risk of CMV infection in kidney transplant recipients

Assessing cytomegalovirus (CMV)-specific cell-mediated immunity (CMI) represents an appealing strategy for identifying transplant recipients at risk of infection. In this study, we compared two gamma interferon-releasing assays (IGRAs), Quantiferon-CMV and CMV enzyme-linked immunosorbent spot (ELISPOT), to determine the ability of each test to predict protective CMV-specific T-cell responses. Two hundred twenty-one Quantiferon-CMV and ELISPOT tests were conducted on 120 adult kidney transplant recipients (KTRs), including 100 CMV-seropositive transplant recipients (R+) and 20 CMV-seronegative transplant recipients of a CMV-positive donor (D+/R-). As a control cohort, 39 healthy adult subjects (including 33 CMV-seropositive and 6 CMV-seronegative subjects) were enrolled. CMV IgG serology was used as a reference for both tests. In the CMV-seropositive individuals, the ELISPOT and Quantiferon-CMV assays provided 46% concordance with the serology, 12% discordance, 18% disagreement between ELISPOT or Quantiferon-CMV and the serology, and 24% gray areas when one or both tests resulted in weak positives. None of the CMV-seronegative subjects showed detectable responses in the ELISPOT or the Quantiferon-CMV test. In transplant recipients, both the ELISPOT and Quantiferon-CMV assays positively correlated with each other and negatively correlated with CMV DNAemia in a significant way (P<0.05). During the antiviral prophylaxis, all 20 D+/R- KTRs we examined displayed undetectable Quantiferon-CMV and ELISPOT results, and there was no evidence of CMV seroconversion. The receiving operator curve (ROC) statistical analysis revealed similar specificities and sensitivities in predicting detectable viremia (areas under the curve [AUC], 0.66 and 0.62 for Quantiferon-CMV and ELISPOT, respectively). ELISPOT and Quantiferon-CMV values of >150 spots/200,000 peripheral blood mononuclear cells (PBMCs) and >1 to 6 IU gamma interferon (IFN-γ) were associated with protection from CMV infection (odds ratios [OR], 5 and 8.75, respectively). In transplant recipients, the two tests displayed similar abilities for predicting CMV infection. Both the ELISPOT and Quantiferon-CMV assays require several ameliorations to avoid false-negative results.

The human cytomegalovirus DNA polymerase processivity factor UL44 is modified by SUMO in a DNA-dependent manner

During the replication of human cytomegalovirus (HCMV) genome, the viral DNA polymerase subunit UL44 plays a key role, as by binding both DNA and the polymerase catalytic subunit it confers processivity to the holoenzyme. However, several lines of evidence suggest that UL44 might have additional roles during virus life cycle. To shed light on this, we searched for cellular partners of UL44 by yeast two-hybrid screenings. Intriguingly, we discovered the interaction of UL44 with Ubc9, an enzyme involved in the covalent conjugation of SUMO (Small Ubiquitin-related MOdifier) to cellular and viral proteins. We found that UL44 can be extensively sumoylated not only in a cell-free system and in transfected cells, but also in HCMV-infected cells, in which about 50% of the protein resulted to be modified at late times post-infection, when viral genome replication is accomplished. Mass spectrometry studies revealed that UL44 possesses multiple SUMO target sites, located throughout the protein. Remarkably, we observed that binding of UL44 to DNA greatly stimulates its sumoylation both in vitro and in vivo. In addition, we showed that overexpression of SUMO alters the intranuclear distribution of UL44 in HCMV-infected cells, and enhances both virus production and DNA replication, arguing for an important role for sumoylation in HCMV life cycle and UL44 function(s). These data report for the first time the sumoylation of a viral processivity factor and show that there is a functional interplay between the HCMV UL44 protein and the cellular sumoylation system.

Viral invasion of the amniotic cavity (VIAC) in the midtrimester of pregnancy

INTRODUCTION

The prevalence of viral infections in the amniotic fluid (AF) has not yet been ascertained. The aim of this study was to determine the prevalence of specific viral nucleic acids in the AF and its relationship to pregnancy outcome.

STUDY DESIGN

From a cohort of 847 consecutive women undergoing midtrimester amniocentesis, 729 cases were included in this study after exclusion of documented fetal anomalies, chromosomal abnormalities, unavailability of AF specimens and clinical outcomes. AF specimens were tested by quantitative real-time PCR for the presence of genome sequences of the following viruses: adenoviruses, herpes simplex virus (HSV), varicella zoster virus (VZV), human herpesvirus 6 (HHV6), human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), parvovirus B19 and enteroviruses. Viral nucleic acid testing was also performed in maternal blood and cord blood in the population of women in whom AF was positive for viruses and in a control group of 29 women with AF negative for viral nucleic acids. The relationship between the presence of viruses and pregnancy and neonatal outcome was examined. The correlation between the presence of nucleic acids of viruses in the AF and the concentration of the cytokine interleukin-6 (IL-6) and the T cell chemokine CXCL-10 (or IP-10) in AF and maternal blood were analyzed.

RESULTS

Viral genome sequences were found in 16 of 729 (2.2%) AF samples. HHV6 was the most commonly detected virus (7 cases, 1.0%), followed by HCMV (6 cases, 0.8%), parvovirus B19 (2 cases, 0.3%) and EBV (1 case, 0.1%), while HSV, VZV, enteroviruses and adenoviruses were not found in this cohort. Corresponding viral DNA was also detected in maternal blood of six out of seven women with HHV6-positive AF and in the umbilical cord plasma, which was available in one case. In contrast, viral DNA was not detected in maternal blood of women with AF positive for parvovirus B19, HCMV, EBV or of women with AF negative for viruses. HHV6 genome copy number in AF and maternal blood was consistent with genomic integration of viral DNA and genetic infection in all women. There was no significant difference in the AF concentration of IL-6 and IP-10 between patients with and without VIAC. However, for HCMV, there was a significant relationship between viral copy number and IP-10 concentration in maternal blood and AF. The group of women with AF positive for viral DNA delivered at term healthy neonates without complications in 14 out of 16 cases. In one case of HHV6 infection in the AF, the patient developed gestational hypertension at term, and in another case of HHV6 infection in the AF, the patient delivered at 33 weeks after preterm premature rupture of membranes (PPROM).

CONCLUSION

Viral nucleic acids are detectable in 2.2% of AF samples obtained from asymptomatic women in the midtrimester. HHV6 was the most frequently detected virus in AF. Adenoviruses were not detected. Vertical transmission of HHV6 was demonstrated in one case.

Human cytomegalovirus-specific T-cell immune reconstitution in preemptively treated heart transplant recipients identifies subjects at critical risk for infection

Human cytomegalovirus (CMV) infection represents a major threat for heart transplant recipients (HTXs). CMV-specific T cells effectively control virus infection, and thus, assessment of antiviral immune recovery may have clinical utility in identifying HTXs at risk of infection. In this study, 10 CMV-seropositive (R(+)) pretransplant patients and 48 preemptively treated R(+) HTXs were examined before and after 100 days posttransplant. Preemptive treatment is supposed to favor the immune recovery. CMV DNAemia and gamma interferon enzyme-linked immunosorbent spot (ELISPOT) assay were employed to assess the viremia and immune reconstitution. HTXs could be categorized into three groups characterized by high (>100), medium (50 to 100), and low (<50) spot levels. Early-identified high responders efficiently controlled the infection and also maintained high immunity levels after 100 days after transplant. No episodes of grade ≥2R rejection occurred in the high responders. Midresponders were identified as a group with heterogeneous trends of immune reconstitution. Low responders were 41% and 21% of HTXs before and after 100 days posttransplant, respectively. Low responders were associated with a higher incidence of infection. The effect of viremia on immune recovery was investigated: a statistically significant inverse correlation between magnitude of viremia and immune recovery emerged; in particular, each 10-fold increase in viremia (>4 log(10) DNAemia/ml) was associated with a 36% decrease of the ELISPOT assay spot levels. All episodes of high viremia (>4 log(10) DNAemia/ml) occurred from 1 to 60 days after transplant. Thus, the concomitant evaluation of viremia and CMV immune reconstitution has clinical utility in identifying HTXs at risk of infection and may represent a helpful guide in making therapeutic choices.

Ultrarapid detection of blaKPC₁/₂-₁₂ from perirectal and nasal swabs by use of real-time PCR

The novel real-time PCR assay developed as described here was able to detect bla(KPC1/2-12) (bla(KPC-1/2) to bla(KPC-12)) from easily available clinical specimens in less than 2 h. The genotypic assay was highly sensitive (100%) and specific (98%). In some cases, it was able to detect bla(KPC) 48 h before positive detection by standard phenotypic assay on patients who were monitored daily. The high sensitivity and rapidity of the molecular method make it the method of choice for KPC surveillance and, thus, containment purposes.

Cytomegalovirus quantification: where to next in optimising patient management?

BACKGROUND

Over the years quantification of cytomegalovirus (HCMV) load in blood has become a mainstay of clinical management helping direct deployment of antiviral therapy, assess response to therapy and highlight cases of drug resistance.

AIMS

The review focuses on a brief historical perspective of HCMV quantification and the ways in which viral load is being used to improve patient management.

METHODS

A review of the published literature and also personal experience at the Royal Free Hospital.

RESULTS

Quantification of HCMV is essential for efficient patient management. The ability to use real time quantitative PCR to drive pre-emptive therapy has improved patient management after transplantation although the threshold viral loads for deployment differ between laboratories. The field would benefit from access to a universal standard for quantification.

CONCLUSIONS

We see that HCMV quantification will continue to be central to delivering individualised patient management and facilitating multicentre trials of new antiviral agents and vaccines in a variety of clinical settings.

The 6-aminoquinolone WC5 inhibits human cytomegalovirus replication at an early stage by interfering with the transactivating activity of viral immediate-early 2 protein

WC5 is a 6-aminoquinolone that potently inhibits the replication of human cytomegalovirus (HCMV) but has no activity, or significantly less activity, against other herpesviruses. Here we investigated the nature of its specific anti-HCMV activity. Structure-activity relationship studies on a small series of analogues showed that WC5 possesses the most suitable pattern of substitutions around the quinolone scaffold to give potent and selective anti-HCMV activity. Studies performed to identify the possible target of WC5 indicated that it prevents viral DNA synthesis but does not significantly affect DNA polymerase activity. In yield reduction experiments with different multiplicities of infection, the anti-HCMV activity of WC5 appeared to be highly dependent on the viral inoculum, suggesting that WC5 may act at an initial stage of virus replication. Consistently, time-of-addition and time-of-removal studies demonstrated that WC5 affects a phase of the HCMV replicative cycle that precedes viral DNA synthesis. Experiments to monitor the effects of the compound on virus attachment and entry showed that it does not inhibit either process. Evaluation of viral mRNA and protein expression revealed that WC5 targets an event of the HCMV replicative cycle that follows the transcription and translation of immediate-early genes and precedes those of early and late genes. In cell-based assays to test the effects of WC5 on the transactivating activity of the HCMV immediate-early 2 (IE2) protein, WC5 markedly interfered with IE2-mediated transactivation of viral early promoters. Finally, WC5 combined with ganciclovir in checkerboard experiments exhibited highly synergistic activity. These findings suggest that WC5 deserves further investigation as a candidate anti-HCMV drug with a novel mechanism of action.

Viral lower urinary tract infections

Lower urinary tract infections (UTIs) are common among the general population and are most often caused by bacterial pathogens. Viruses are an uncommon cause of UTIs in an immunocompetent host; however, viruses are increasingly recognized as the cause of lower UTI, especially hemorrhagic cystitis, among immunocompromised patients. BK virus, adenovirus, and cytomegalovirus are predominant pathogens involved in hemorrhagic cystitis after stem cell and solid organ transplantation, and their early diagnosis and treatment may prevent significant morbidity of hemorrhagic cystitis. The diagnosis of viral lower UTI is based on molecular techniques, and real-time polymerase chain reaction is often the method of choice because it allows for quantification of viral load. Cidofovir is becoming a drug of choice in viral UTIs because it is active against the most common viral pathogens. This review discusses the epidemiology, pitfalls in diagnosis, and current treatment of viral UTIs.

Multiplex detection of human herpesviruses from archival specimens by using matrix-assisted laser desorption ionization-time of flight mass spectrometry

The human herpesviruses are involved in a variety of diseases. Large-scale evaluation of the clinical and epidemiological importance of different herpesviruses requires high-throughput methods. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a method that has a multiplex capacity enabling simultaneous detection of several viruses in a single sample. PCR-based methods for the multiplex detection of all known human herpesviruses were developed on the MALDI-TOF MS system. A variety of 882 archival samples, including bronchoalveolar lavage, conjunctival fluid, sore secretion, blister material, plasma, serum, and urine, analyzed for herpesviruses using PCR-based reference methods, were used to evaluate the MALDI-TOF MS method. The overall concordance rate between the MALDI-TOF MS method and the reference methods was 95.6% (kappa = 0.90). In summary, the MALDI-TOF MS method is well suited for large-scale detection of all known human herpesviruses in a wide variety of archival biological specimens.

Quantitative real-time polymerase chain reaction for evaluating DNAemia due to cytomegalovirus, Epstein-Barr virus, and BK virus in solid-organ transplant recipients

Testing for cytomegalovirus-, Epstein-Barr virus-, and BK virus-specific gene targets in specimens from solid-organ transplant recipients for DNA by quantitative real-time polymerase chain reaction has been implemented in many diagnostic facilities. This technology provides rapid, accurate, and reproducible results for early detection, monitoring, and medical management of patients with these infections. Because these assays are becoming commonly used in clinical practice, the technical variables associated with specimen processing (e.g., nucleic acid extraction, gene target, and result reporting), amplification, and unique patient characteristics (e.g., age, sex, underlying diseases, immune status, and immunosuppressive regimens received) are factors that may influence the understanding and interpretation of test results. We emphasize the need for standardization of existing variables through parallel comparative and proficiency testing, uniform units for expressing results, to provide for clinical correlation with the results of these molecular assays.

Detection of polyomaviruses and herpesviruses in human adrenal tumors

The presence of polyomaviruses and herpesviruses in adrenal tumors and their role in adrenal tumorigenesis has never been investigated, even though the adrenal gland seems to be a preferential site of infection by these viruses and adrenal steroid hormones have been shown to activate their replication. We examined in a large series of normal adrenal gland tissues (n=20) and adrenal tumors (n=107) the presence of herpesviruses and polyomaviruses sequences and gene expression, which were detected in a high proportion of both normal and neoplastic adrenal samples (overall, viruses were found in 15% normal adrenals, 27.8% benign adrenal tumors and 35.3% malignant tumors). The polyomaviruses SV40 and BK virus were more frequently found in malignant adrenal tumors, whereas herpesviruses, especially Epstein-Barr virus and human cytomegalovirus, were more frequently detected in functioning benign adrenocortical tumors, often as coinfection. Moreover, tumors from patients with severe hypercortisolism frequently showed herpesvirus coinfections at high viral genome copy number. Our study suggests that the adrenal gland could be a reservoir of infection for these viruses and that hormone overproduction by the adrenal gland could represent a trigger for virus reactivation. On the other hand, these viruses could also contribute to adrenal cell proliferation and tumorigenesis.

Viral lower urinary tract infections

Lower urinary tract infections (UTIs) are common among the general population and are most often caused by bacterial pathogens. Viruses are an uncommon cause of UTIs in an immunocompetent host; however, viruses are increasingly recognized as the cause of lower UTI, especially hemorrhagic cystitis, among immunocompromised patients. BK virus, adenovirus, and cytomegalovirus are predominant pathogens involved in hemorrhagic cystitis after stem cell and solid organ transplantation, and their early diagnosis and treatment may prevent significant morbidity of hemorrhagic cystitis. The diagnosis of viral lower UTI is based on molecular techniques, and real-time polymerase chain reaction is often the method of choice because it allows for quantification of viral load. Cidofovir is becoming a drug of choice in viral UTIs because it is active against the most common viral pathogens. This review discusses the epidemiology, pitfalls in diagnosis, and current treatment of viral UTIs.

Diagnostic value of reverse transcription-PCR for detection of cytomegalovirus pp67 in samples from solid-organ transplant recipients

We evaluated a highly sensitive quantitative real-time one-step reverse transcription-PCR (RT-PCR) for detection of human cytomegalovirus pp67 transcripts in monitoring of solid-organ transplant recipients. Results were compared with those of pp65 antigen testing and quantitative DNA-PCR. Due to a low clinical sensitivity, the pp67 RT-PCR was not able to replace these assays.

Cytomegalovirus infection in ulcerative colitis

OBJECTIVE

Cytomegalovirus (CMV) infection has been reported as an exacerbating factor in inflammatory bowel disease but the relationship between CMV infection and ulcerative colitis (UC) remains unclear. There has been no detailed research to elucidate the clinicopathologic features of CMV infection in UC using surgical specimens. The aim of this study was to investigate the clinicopathologic features of CMV infection in UC patients who had undergone colectomy.

MATERIAL AND METHODS

Surgical specimens taken from UC patients were examined for CMV infection. The patients were divided into three groups: severe, refractory, and UC-associated dysplasia or cancer according to the operative indications. CMV infection rates were evaluated and a comparison of clinical parameters was made between CMV-positive and CMV-negative patients, and the risk factors for CMV infection were analyzed using multivariate analyses.

RESULTS

It was found that 25% of 32 patients were positive for CMV in the severe UC group; 8.3% of 72 patients were positive for CMV in the refractory UC group. None of the 22 patients was positive for CMV in the UC-associated dysplasia or cancer group. The CMV-positive rate in the severe UC group was significantly higher than that in the other groups (p<0.05). Patients' age at the time of operation was higher in the CMV-positive group than in the CMV-negative group among the patients with severe UC (p<0.01), and age at operation was an independent risk factor for CMV infection.

CONCLUSIONS

CMV is found more frequently in severe UC than refractory UC and UC-associated cancer or dysplasia. Higher age can be a risk factor for CMV infection in patients with severe UC. However, a high steroid dose may not always be a risk factor for CMV infection.

LightUp probes in clinical diagnostics

The LightUp^® Probe technology has now matured and reached the phase where it has been implemented in commercial reagent kits, i.e. the ReSSQ^® product line. Several properties of the LightUp^® probes make them particularly suitable for clinical settings. For instance, extraordinary shelf life and a chemical stability that allows convenient fridge storage. The origin of the higher stability of LightUp^® probe kits compared to others, based on alternative probe technologies, is partly the relatively good stability of cyanine dyes but also the resistance towards nucleases and proteases of the synthetic DNA analogue peptide nucleic acid that is used as the sequence recognizing element in LightUp probes. It is clear from recent trends in the PCR amplification hardware technology that the instrumentation is becoming more flexible and less adapted for dedicated probe chemistries. This will pave the way for increased standardization in the field of DNA diagnostics and the development of cross-platform assays.

In the present review the LightUp technology will briefly be presented and discussed. The utility of the technology will be illustrated by examples from cytomegalovirus quantification and monitoring of the viral load of the SARS Coronavirus. An example of cancer diagnostics by detection of altered gene expression patterns will also be shown.

Discrimination of Acute Graft-versus-Host Disease from Infections by Enumeration of Peripheral Blood Interferon-?? Spot-Forming Cells

Infections may coexist and in certain circumstances aggravate acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation. Early detection of aGVHD is often difficult in patients with concurrent infections. Using an enzyme-linked immunospot assay that reflects ongoing immune status in vivo, we enumerated spot-forming cells (SFCs) for interferon (IFN)-gamma, interleukin (IL)-4, and IL-12 in peripheral blood from 56 patients with hematological disorders. Eleven patients had viral, fungal, or bacterial systemic infections during first 10 weeks posttransplant. Of these, six patients with grade 0-I aGVHD showed normal levels of IFN-gamma SFCs. On the other hand, IFN-gamma SFCs were elevated in five patients with grade II-IV aGVHD. These data indicate that increased IFN-gamma SFCs seemed to be correlated with clinically significant aGVHD, but not with infection itself. IL-4 and IL-12 SFCs increased in some patients with infections, irrespective of the presence of aGVHD. Thus, IFN-gamma SFCs may be used to distinguish systemic infections from aGVHD.

Amplifying control RNA for RT-PCR applications by nucleic acid sequence based amplification (NASBA)

Control RNA for RT-PCR applications was amplified by nucleic acid sequence based amplification (NASBA) using the NucliSens Basic Kit. This method was used to construct positive control RNA for enterovirus, insulin, and G-protein RT-PCR, and for interferon-alpha real-time RT-PCR. The primers were designed to amplify identical RNA from RNA templates, which differs from the usual NASBA procedure, where opposite strand RNA is amplified from the target. This "inverse NASBA" method is easy to use and it does not require any expensive special equipment. The amplification reaction is done using a water bath and detection of amplified product by agarose gel electrophoresis. Generated RNA fragments were 195-714 bases long, of positive polarity and the amount of RNA was sufficient for thousands of RT-PCR reactions depending on the sensitivity of the RT-PCR.

A touchdown nucleic acid amplification protocol as an alternative to culture backup for immunofluorescence in the routine diagnosis of acute viral respiratory tract infections

Background

Immunofluorescence and virus culture are the main methods used to diagnose acute respiratory virus infections. Diagnosing these infections using nucleic acid amplification presents technical challenges, one of which is facilitating the different optimal annealing temperatures needed for each virus. To overcome this problem we developed a diagnostic molecular strip which combined a generic nested touchdown protocol with in-house primer master-mixes that could recognise 12 common respiratory viruses.

Results

Over an 18 month period a total of 222 specimens were tested by both immunofluorescence and the molecular strip. The specimens came from 103 males (median age 3.5 y), 80 females (median age 9 y) and 5 quality assurance scheme specimens. Viruses were recovered from a number of specimen types including broncho-alveolar lavage, nasopharyngeal secretions, sputa, post-mortem lung tissue and combined throat and nasal swabs. Viral detection by IF was poor in sputa and respiratory swabs. A total of 99 viruses were detected in the study from 79 patients and 4 quality control specimens: 31 by immunofluorescence and 99 using the molecular strip. The strip consistently out-performed immunofluorescence with no loss of diagnostic specificity.

Conclusions

The touchdown protocol with pre-dispensed primer master-mixes was suitable for replacing virus culture for the diagnosis of respiratory viruses which were negative by immunofluorescence. Results by immunofluorescence were available after an average of 4–12 hours while molecular strip results were available within 24 hours, considerably faster than viral culture. The combined strip and touchdown protocol proved to be a convenient and reliable method of testing for multiple viruses in a routine setting.