Cytomegalovirus mononucleosis in children and adults: differences in clinical presentation

Viruses in colorectal cancer

Increasing evidence suggests that microorganisms might represent at least highly interesting cofactors in colorectal cancer (CRC) oncogenesis and progression. Still, associated mechanisms, specifically in colonocytes and their microenvironmental interactions, are still poorly understood. Although, currently, at least seven viruses are being recognized as human carcinogens, only three of these – Epstein–Barr virus (EBV), human papillomavirus (HPV) and John Cunningham virus (JCV) – have been described, with varying levels of evidence, in CRC. In addition, cytomegalovirus (CMV) has been associated with CRC in some publications, albeit not being a fully acknowledged oncovirus. Moreover, recent microbiome studies set increasing grounds for new hypotheses on bacteriophages as interesting additional modulators in CRC carcinogenesis and progression. The present Review summarizes how particular groups of viruses, including bacteriophages, affect cells and the cellular and microbial microenvironment, thereby putatively contributing to foster CRC. This could be achieved, for example, by promoting several processes – such as DNA damage, chromosomal instability, or molecular aspects of cell proliferation, CRC progression and metastasis – not necessarily by direct infection of epithelial cells only, but also by interaction with the microenvironment of infected cells. In this context, there are striking common features of EBV, CMV, HPV and JCV that are able to promote oncogenesis, in terms of establishing latent infections and affecting p53‐/pRb‐driven, epithelial–mesenchymal transition (EMT)‐/EGFR‐associated and especially Wnt/β‐catenin‐driven pathways. We speculate that, at least in part, such viral impacts on particular pathways might be reflected in lasting (e.g. mutational or further genomic) fingerprints of viruses in cells. Also, the complex interplay between several species within the intestinal microbiome, involving a direct or indirect impact on colorectal and microenvironmental cells but also between, for example, phages and bacterial and viral pathogens, and further novel species certainly might, in part, explain ongoing difficulties to establish unequivocal monocausal links between specific viral infections and CRC.

Lymphoma-Like Syndrome: 4 Case Reports About Atypical Presentation of Primary Cytomegalovirus Infection in Immunocompetent Children

In immunocompetent persons, primary cytomegalovirus (CMV) infection is self-limited infection. Lymphoma-like syndromes have been sometimes described in adults but have not been described for children.Lymphoma-like syndromes (protracted fever, alteration of the general status, and clinical lymphoproliferative syndrome) were retrospectively recorded in children attending our hospital from 1999 to 2008 for primary CMV infection. Patients with immunodeficiency, coinfection (Epstein-Barr virus, toxoplasmosis, or mycobacterial), or biological criteria of mononucleosis-like syndrome were excluded.We report 4 cases of lymphoma-like syndrome. The median duration of fever was 21.5 days (range 15-27). Tonsillitis and hepatitis are most of the time missing. A probable malignant diagnosis was raised in 3 cases. Clinical outcome was protracted (15-35 days) but favorable.To our knowledge, our study is the first pediatric case series of lymphoma-like syndrome. This clinical presentation is a source of delayed diagnosis due to diagnosis pitfall.

Clinical pharmacokinetics and pharmacodynamics of ganciclovir and valganciclovir in children with cytomegalovirus infection

INTRODUCTION

Among infants and immunocompromised children cytomegalovirus (CMV) is associated with significant morbidity and mortality.

AREAS COVERED

This review describes the clinical pharmacokinetics and pharmacodynamics of ganciclovir and valganciclovir for the treatment and prevention of CMV infection in children.

EXPERT OPINION

A 24-h ganciclovir area under the concentration versus time curve (AUC₀₋₂₄) of 40 - 60 μg h/ml decreased the risk of CMV infection for adults undergoing CMV prophylaxis. For adults undergoing treatment for active CMV disease, a target AUC₀₋₁₂ of 40 - 60 μg h/ml has been suggested. The applicability of these targets to children remains uncertain; however, with the most sophisticated dosing regimens developed to date only 21% of patients are predicted to reach these targets. Moving forward, identification of optimal pediatric ganciclovir and valganciclovir dosing regimens may involve the use of an externally validated pediatric population pharmacokinetic model for empirical dosing, an optimal sampling strategy for collecting a minimal number of blood samples for each patient and Bayesian updating of the dosing regimen based on an individual patient's pharmacokinetic profile.

Human cytomegalovirus persistence

Viral persistence is the rule following infection with all herpesviruses. The β-herpesvirus, human cytomegalovirus (HCMV), persists through chronic and latent states of infection. Both of these states of infection contribute to HCMV persistence and to the high HCMV seroprevalence worldwide. The chronic infection is poorly defined molecularly, but clinically manifests as low-level virus shedding over extended periods of time and often in the absence of symptoms. Latency requires long-term maintenance of viral genomes in a reversibly quiescent state in the immunocompetent host. In this review, we focus on recent advances in the biology of HCMV persistence, particularly with respect to the latent mode of persistence. Latently infected individuals harbour HCMV genomes in haematopoietic cells and maintain large subsets of HCMV-specific T-cells. In the last few years, impressive advances have been made in understanding virus-host interactions important to HCMV infection, many of which will profoundly impact HCMV persistence. We discuss these advances and their known or potential impact on viral latency. As herpesviruses are met with similar challenges in achieving latency and often employ conserved strategies to persist, we discuss current and future directions of HCMV persistence in the context of the greater body of knowledge regarding α- and γ-herpesviruses persistence.

Utility of blood cultures in postoperative pediatric intensive care unit patients

OBJECTIVE

To determine the frequency of positive blood cultures in patients with fevers in the initial 48-hour postoperative period.

STUDY DESIGN

All patients who had blood cultures drawn during the initial 48 hours postoperatively while in the pediatric intensive care unit (PICU) at the University of Minnesota Children's Hospital-Fairview during an 18-month period were included in the current study. Six hundred two postoperative patients were admitted to the PICU during the study period. Patients with a temperature >100.4 degrees F and who had blood cultures drawn were identified. Patients for whom the operative procedure was not the first in that admission, those discharged in <48 hours, and those with an indwelling central venous catheter for >24 hours before their admission were excluded.

RESULTS

Sixty-six of these patients were febrile and had blood cultures drawn in the initial 48 hours postoperatively. One hundred eleven blood cultures were obtained. A single (0.9%) blood culture was positive. The cost per positive culture was estimated at $23,532.

CONCLUSIONS

Even in patients admitted to the PICU, fever in the initial 48-hour postoperative period is unlikely to represent bacteremia in low-risk pediatric patients. Blood cultures in these patients are, therefore, unlikely to yield positive results. Procurement of blood cultures in this patient population is not justified. Cessation of the practice of blood culture procurement in this patient population may both focus care and provide enable meaningful cost savings.

Manifestations of human cytomegalovirus infection: proposed mechanisms of acute and chronic disease

Infections with human cytomegalovirus (HCMV) are a major cause of morbidity and mortality in humans with acquired or developmental deficits in innate and adaptive immunity. In the normal immunocompetent host, symptoms rarely accompany acute infections, although prolonged virus shedding is frequent. Virus persistence is established in all infected individuals and appears to be maintained by both a chronic productive infections as well as latency with restricted viral gene expression. The contributions of the each of these mechanisms to the persistence of this virus in the individual is unknown but frequent virus shedding into the saliva and genitourinary tract likely accounts for the near universal incidence of infection in most populations in the world. The pathogenesis of disease associated with acute HCMV infection is most readily attributable to lytic virus replication and end organ damage either secondary to virus replication and cell death or from host immunological responses that target virus-infected cells. Antiviral agents limit the severity of disease associated with acute HCMV infections, suggesting a requirement for virus replication in clinical syndromes associated with acute infection. End organ disease secondary to unchecked virus replication can be observed in infants infected in utero, allograft recipients receiving potent immunosuppressive agents, and patients with HIV infections that exhibit a loss of adaptive immune function. In contrast, diseases associated with chronic or persistent infections appear in normal individuals and in the allografts of the transplant recipient. The manifestations of these infections appear related to chronic inflammation, but it is unclear if poorly controlled virus replication is necessary for the different phenotypic expressions of disease that are reported in these patients. Although the relationship between HCMV infection and chronic allograft rejection is well known, the mechanisms that account for the role of this virus in graft loss are not well understood. However, the capacity of this virus to persist in the midst of intense inflammation suggests that its persistence could serve as a trigger for the induction of host-vs-graft responses or alternatively host responses to HCMV could contribute to the inflammatory milieu characteristic of chronic allograft rejection.

Transfusion-transmitted cytomegalovirus (CMV) infections in a murine model: characterization of CMV-infected donor mice

BACKGROUND

Donor and recipient mechanisms that modulate the incidence and severity of transfusion-transmitted cytomegalovirus (TT-CMV) are unclear. The kinetics of murine CMV (MCMV) infection in the peripheral blood of donor mice were investigated to determine the utility of this model for studying TT-CMV.

STUDY DESIGN AND METHODS

BALB/cByJ mice, experimentally infected with Smith strain MCMV, were killed at serial time points up to 28 days after infection. Peritoneal exudate cells (PECs), peripheral blood white blood cells (WBCs), plasma, and marrow were tested for MCMV DNA with quantitative polymerase chain reaction (PCR), replication-competent virus with quantitative culture, and transcription of viral genes with reverse transcription (RT)-PCR targeted at the immediate-early 1 (ie1) gene.

RESULTS

PECs, macrophages infected by MCMV shortly after intraperitoneal inoculation, demonstrated high mean levels of MCMV DNA (10(5)-10(7) genome equivalents [geqs]/10(5) PECs), virus production (10(1)-10(4) infectious virions/10(5) PECs), and ie1 gene transcription, demonstrating productive infection. In contrast, while MCMV loads averaged 10(4) to 10(6) geqs per 10(5) peripheral WBCs, all WBC samples were uniformly negative for MCMV ie1 expression by RT-PCR and for culturable virus, consistent with latent MCMV infection. Plasma and marrow showed lower viral loads than WBCs and PECs and were all negative by culture and RT-PCR analysis.

CONCLUSIONS

Following experimental MCMV infection, murine peripheral blood WBCs appear to be latently infected with virus (MCMV DNA-positive; MCMV RNA-negative; MCMV culture-negative), similar to the latently infected human monocytes in peripheral blood of CMV-seropositive donors. These donor kinetics suggest that the experimental MCMV system can be used to effectively model the mechanisms of TT-CMV infections in humans.

Determination of safe return to play for athletes recovering from infectious mononucleosis: a review of the literature

OBJECTIVE

Infectious mononucleosis is an acute self-limited disorder diagnosed by clinical and hematologic measures. This paper reviews the literature regarding the decision-making process for return to play in individuals at risk for complications due to infectious mononucleosis.

DATA SOURCES

Computerized literature search identified articles using the keywords infectious mononucleosis, athlete, injury, exercise, spleen rupture, and spleen radiography. Symptoms, physical examination, hematological markers, and radiographic evaluation were considered.

CONCLUSIONS

No strong evidence-based information supports use of a single parameter to predict the safe return to sports participation. Current consensus supports that athletes be afebrile, well hydrated, and asymptomatic with no palpable liver or spleen. Clinical judgment incorporating these criteria 1 month after diagnosis has been suggested as a safe predictor for gradual return to competition. These conditions for return to play do not guarantee that the spleen has returned to normal size and compliance, or that the risk of spleen rupture has returned to baseline. For those athletes participating in contact sports who wish to return to sports in an earlier time frame, or those with an equivocal examination, radiographic modalities may be used to help determine liver and spleen size. Further studies are required to support this practice.

Clinical and histological features of cytomegalovirus hepatitis in previously healthy adults

It is well known that cytomegalovirus infection is often accompanied by hepatitis, but there have been few comparative studies with respect to clinical features of cytomegalovirus-associated hepatitis and other acute viral hepatitides. In the present study, clinical and pathological features of 11 acute sporadic cytomegalovirus hepatitis infections in previously healthy adults were compared with those of 45 acute sporadic viral hepatitis, including type A, type B and type C. As a result, the characteristics of cytomegalovirus hepatitis were a long-lasting fever, splenomegaly, atypical lymphocytosis, a mild transaminasemia, a low ratio of alanine aminotransferase level to lactate dehydrogenase level, and mild hepatic histopathological changes.

Cytomegalovirus mononucleosis in children compared with the infection in adults and with Epstein-Barr virus mononucleosis

We report clinical and laboratory findings in 11 previously healthy children with cytomegalovirus (CMV) mononucleosis and compare them with those of 18 adults with CMV mononucleosis and with those of 22 age-matched children with Epstein-Barr virus (EBV) mononucleosis. Exudative pharyngitis was more common in children whereas prolonged fever was more common in adults. Prominent lymphadenopathy and exudative pharyngitis, however, were less frequent in children with CMV mononucleosis than in those with EBV mononucleosis. Nevertheless, children with CMV mononucleosis are more likely to resemble those with EBV mononucleosis than adults with CMV mononucleosis.

[Detection of IgM antibodies in primary and secondary infections by cytomegalovirus in patients subjected to renal transplantation]

Foram acompanhados 27 pacientes submetidos a transplante renal para avaliação do comportamento dos anticorpos IgM e IgG CMV-específicos. Dos 27 casos estudados, 17 (63,0%) tinham anticorpos IgG, detectados pela reação de fixação de complemento (RFC), antes de serem submetidos ao transplante, e 10 (37,0%) eram soro negativos. A pesquisa de anticorpos IgM (técnica de imunofluorescência indireta) foi negativa em todas as amostras pré transplante. Num período de acompanhamento que variou de 28 a 425 dias (média de 115 dias) após o transplante, observou-se que 20 dos 27 (74,1%) apresentaram evidências sorológicas de infecçáo pelo CMV, ocorrendo a maioria dos casos (14/20, 70%) em pacientes que já tinham anticorpos para o CMV antes do transplante. A pesquisa de anticorpos IgM CMV-específicos foi positiva em 12 dos 14 pacientes com evidências sorológicas de reinfecção ou reativação da infecção pelo CMV, e em 100% (6/6) dos pacientes com infecção primária. Dentre os 10 pacientes acompanhados por mais de 4 meses, somente 1 (10%) negativou o IgM neste período.