Latent Cytomegalovirus Infection Research Articles

Socioeconomic disparities in the seroprevalence of cytomegalovirus infection in the US population: NHANES III.

There is a strong relationship between socioeconomic status (SES) and health outcomes in the United States, although the mechanisms are poorly understood. Increasing evidence points to links between lifelong exposure to infectious disease and subsequent chronic disease. Exposure and susceptibility to infections may be one way SES affects long-term health, although little population-based research to date has examined social patterning of infections in the United States. This paper tests the relationship between income, education, race/ethnicity and seroprevalence of cytomegalovirus (CMV) infection at different ages in a representative sample of the US population, and tests potential mediators for these relationships. The study finds significant racial and socioeconomic disparities in CMV seroprevalence beginning at early ages and persisting into middle age. Potential exposures do not explain the relationship between SES and CMV positivity. Because reactivation of latent CMV infections may contribute to chronic disease and immune decline later in life, future research should determine the exposure or susceptibility pathways responsible for these disparities in the prevalence of CMV infection.

TNF Receptor Independent Activation of the Cytomegalovirus Major Immediate Early Enhancer in Response to Transplantation

Reactivation of latent human cytomegalovirus (HCMV) infection is a significant risk factor for long term allograft dysfunction. The molecular pathways involved in reactivation of latent virus have not been identified. Previous studies suggested that tumor necrosis factor (TNF) -mediated activation of nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-kappa B) leading to transcriptional reactivation of viral immediate early (ie) gene expression might be important in transplant-associated viral reactivation. CMV IE gene expression is controlled by the major immediate early promoter/enhancer (MIEP). Because HCMV does not infect mice, transgenic mice carrying a beta-galactosidase reporter gene under the control of the HCMV immediate early enhancer (MIEP-lacZ mice) are a valuable model for studying regulation of CMV IE gene expression in vivo. We have used TNF receptor-deficient MIEP-lacZ (MIEP-lacZ TNFR DKO) mice to study the requirement for TNF in transplant-induced activation of the MIEP. Allogenic kidney transplants were performed using MIEP-lacZ TNFR DKO or MIEP-lacZ TNFRwild-type donor mice. beta-Galactosidase activity was used to measure activation of the IE enhancer in donor kidneys at 2 days of posttransplantation and in contralateral controls. Transcription factor activation was assayed with Trans-Am kits. Allogenic and syngenic transplantation activate the HCMV IE enhancer to the same extent. TNF receptor signaling was not required for activation of the MIEP. TNF receptor signaling was required for activation of NF-kappaB, but not for activation of activating protein 1 family members junD and Fra-1 in day 2 allografts. TNF-independent pathways can activate the enhancer in response to allogenic transplantation. This may occur through activation of MIEP-binding transcription factors other than NF-kappa B.

Clinical features of late cytomegalovirus infection after hematopoietic stem cell transplantation

Late cytomegalovirus (CMV) disease beyond day 100 after hematopoietic stem cell transplantation (HSCT) has become an increasing problem after the introduction of preemptive ganciclovir (GCV) administration. To clarify the risk factors and outcome for late CMV reactivation and disease, we retrospectively analyzed the records of 101 Japanese adult patients who underwent allogeneic HSCT between 1998 and 2005 at our hospital. Fifty-one developed late positive CMV antigenemia, with a cumulative incidence of 53%. Recipient CMV seropositivity, the use of alemtuzumab, chronic GVHD, and high-dose steroids were significantly associated with late positive antigenemia. Eight patients developed late CMV disease, with a cumulative incidence of 8%, including retinitis and gastrointestinal disease. None progressed to a fatal disease. The use of alemtuzumab was identified as an independent significant risk factor for late CMV disease, although it was not associated with increased non-relapse mortality. Among the 51 patients with late positive antigenemia, 28 had consistently less than three positive cells, 25 of whom showed negative conversion without antiviral agents. In conclusion, late CMV antigenemia appeared to develop frequently, especially in patients with profound immune suppression; however, a fatal outcome could be prevented by optimal preemptive therapy. Low-level antigenemia may not require antiviral treatments.

Attack of the CD4 clones

Latent human cytomegalovirus (CMV) infection is associated with vast clonal expansions of cytotoxic CD8+ and CD4+ T cells.

Human cytomegalovirus-specific CD4+ and CD8+ T-cell reconstitution in adult allogeneic hematopoietic stem cell transplant recipients and immune control of viral infection

Human cytomegalovirus infection is the most frequent viral complication in patients undergoing hematopoietic stem cell transplantation. We investigated the development of human cytomegalovirus-specific T cells in adult recipients of hematopoietic stem cell transplants. From May 2003 through October 2006 a total of 45 patients were monitored for human cytomegalovirus-specific T-cell reconstitution. Human cytomegalovirus-infected autologous dendritic cells were used as a stimulus to detect interferon-gamma-producing human cytomegalovirus-specific CD8(+) and CD4(+) T cells during the first year after transplantation. Interleukin-2 production by specific T cells was also determined. Human cytomegalovirus infection was detected in the blood of 39/45 patients at a median of 29 days after transplantation. Human cytomegalovirus-specific T-cell reconstitution followed reactivation of latent human cytomegalovirus infection at a median time of about 2 months after transplantation. Only donor human cytomegalovirus-seronegativity and bone marrow as a stem cell source were found to delay specific T-cell reconstitution significantly. Levels of three CD8(+) and one CD4(+) human cytomegalovirus-specific T-cells/microL blood had a positive predictive value of around 80% for identifying patients able to control human cytomegalovirus infection spontaneously. Five patients who received high doses of steroids for treatment of graft-versus-host disease developed human cytomegalovirus infection requiring pre-emptive treatment despite high levels of interferon-gamma-producing T cells in response to human cytomegalovirus. Specific interleukin-2 production was not detected in patients with human cytomegalovirus infection requiring treatment, while 90% of patients who spontaneously controlled human cytomegalovirus infection had T cells that produced interleukin-2 and interferon-gamma. Pre-transplant human cytomegalovirus infection of the recipient is a major factor driving human cytomegalovirus-specific immune reconstitution. Control of human cytomegalovirus infection likely requires the presence of both interferon-gamma and interleukin-2 producing T cells. Corticosteroid treatment may favor active viral replication even in patients with specific T cells.

CMV-Associated Expansion of CD8+CD45RA+CD27− T-Cells in Patients with B-Cell Malignancies.

In patients with various malignancies of B-cell origin, changes in the T-cell compartment have been observed. In B-cell chronic lymphocytic leukemia (CLL), we have previously described an expansion of T-cells, largely due to an increase in T-cells exhibiting the CD45RA+CD27- effector phenotype. This was found only in cytomegalovirus (CMV) seropositive patients, suggesting that CMV-antigen drives this expansion. Indeed a considerable fraction of these T-cells were shown to be CMV-specific. At present it is unknown whether this alteration of the T-cell compartment is specific for CLL or rather any B-cell malignancy could induce similar changes. We performed an immunophenotypic analysis of the T-cell compartment in the peripheral blood of 56 patients with a B-cell malignancy (CLL, n=16; indolent lymphoma, n=20; aggressive lymphoma, n=10; multiple myeloma, n=10) and 12 healthy controls. Subjects of the different disease categories and controls were age-matched. We assessed the total CD3 compartment, naïve (CD27+CD45RA+), memory (CD27+CD45RA−) and memory effector (CD27−CD45RA+) CD8+ T cells. Latent CMV infection was assessed both by CMV-IgG titers (ELISA) and CMV viral load (PCR). The absolute number of T-cells was significantly increased (2.5 – 3 fold) in CLL, but not in the other B-cell malignancies. However, in all disease categories the CD4/CD8 ratio was decreased when compared to healthy controls. This was due to a slight decrease in CD4+ T-cells and an increase in CD8+ T-cells. Irrespective of the nature of the malignancy, the expansion of CD8+ T-cells resulted from a significant increase in CD45RA+CD27− effector T-cells. In agreement with our previous observation, CD8+ T-cell changes were only found in CMV-seropositive patients. Based on our earlier studies we expect these T-cells to be CMV-specific. No correlation between CMV-specific antibody titers and effector T-cell numbers was found. We conclude that the, possibly CMV-specific, effector T-cell compartment is expanded in all B-cell maligancies, although these changes seem to be more pronounced in CLL. The expansion of the total T cell compartment is restricted to CLL. The skewing of the T-cell compartment in CMV-seropositive patients could be the result of increased pressure of latent CMV-infection on the cellular immune system due to failure of other aspects of host defence, brought about by the malignancy.

Incidental discovery of high systemic lupus erythematosus disease activity associated with cytomegalovirus viral activity

We try to find the association of cytomegalovirus (CMV) infection and anti-beta2 glycoprotein 1 autoantibodies (anti-beta2 GP1), a key antibody in antiphospholipid syndrome (APS), among systemic lupus erythematosus (SLE) and cerebral vascular accident (CVA) patients. This retrospective study enrolled serum samples obtained from 87 SLE and 97 CVA patients who have been checked for the existence of anti-beta2 GP1. First, the prevalence rate of anti-CMV IgG and IgM in patients with and without anti-beta2 GP1 were compared. Second, the prevalence of anti-CMV IgG and IgM were compared between SLE and CVA patients. Last, this study analyzed the clinical characteristics and disease activity in SLE patients with positive anti-CMV IgM and IgG. No difference existed in the prevalence rate of anti-CMV IgG and IgM between positive or negative anti-beta2 GP1 serum samples in both SLE and CVA patients. However, the prevalence of anti-CMV IgM was significantly higher in the SLE group than in the CVA group. Severity of clinical features and SLEDAI scores were considerably higher in patients with positive anti-CMV IgM than in SLE patients with negative anti-CMV IgM. Very impressively, all IgM-positive SLE samples (9/9) carrying highest levels of anti-CMV IgG, indicated reactivation of the latent CMV infection. Hence, it suggests that CMV reactivation might contribute toward the disease flare in some SLE patients. In future, a prospective and longitudinal study is stongly indicated.

Viral gene expression during the establishment of human cytomegalovirus latent infection in myeloid progenitor cells

AbstractHuman cytomegalovirus (HCMV) establishes and maintains a latent infection in myeloid cells and can reactivate to cause serious disease in allograft recipients. To better understand the molecular events associated with the establishment of latency, we tracked the virus following infection of primary human myeloid progenitor cells at days 1, 2, 3, 5, and 11. At all time points, the viral genome was maintained in most cells at approximately 10 copies. Infectious virus was not detected, but virus could be reactivated by extended fibroblast coculture. In contrast to wild-type HCMV, the viral genome was rapidly lost from myeloid progenitors infected with ultraviolet (UV)–inactivated virus, suggesting viral gene expression was required for efficient establishment of latency. To identify viral genes associated with the establishment phase, RNA from each time point was interrogated using custom-made HCMV gene microarrays. Using this approach, we detected expression of viral RNAs at all time points. The pattern of expression differed from that which occurs during productive infection, and decreased over time. This study provides evidence that a molecular pathway into latency is associated with expression of a unique subset of viral transcripts. Viral genes expressed during the establishment phase may serve as targets for therapies to interrupt this process.

Screening for vaginal shedding of cytomegalovirus in healthy pregnant women using real‐time PCR: Correlation of CMV in the vagina and adverse outcome of pregnancy

The impact of cytomegalovirus (CMV) infection of the genital tract during pregnancy on adverse pregnancy outcomes is not understood fully. A real-time PCR assay was used to determine vaginal shedding of CMV in 993 healthy pregnant Japanese women and the results were compared with the outcome of pregnancy. CMV DNA was detected in 76 (7.7%) of the women. The outcome of pregnancy could be determined finally in 848 women, of whom 60 (7.1%) were CMV positive. The carriers of CMV had an increased miscarriage rate (RR 6.96, 95% CI 2.04-23.84, P < 0.01). These findings suggest that latent genital tract CMV infection predisposes to adverse pregnancy outcomes.

Viral Infections in Patients with Hematological Malignancies

Viral infections are important causes of morbidity and mortality for patients with a hematological malignancy. However, the true incidence and consequences of viral infections for these patients who undergo conventional nontransplant therapy are poorly defined. The difference in incidence and outcome of viral infections among patient groups is wide, but dependent upon the intensity and duration of T-cell-mediated immune suppression. Infections caused by cytomegalovirus (CMV), herpes simplex virus (HSV), varicella-zoster virus (VZV), respiratory syncytial virus (RSV), parainfluenza viruses and influenza viruses have been intensely studied, yet newly recognized aspects of these viral infections including late CMV infection; the emergence of new viral pathogens (human herpesvirus-6, BK virus, adenovirus, and human metapneumovirus); the development of molecular diagnostic techniques, and the potential of new agents for viral prophylaxis (maribavir), or preemptive therapy (valganciclovir) form the basis of this review. Well-designed prospective studies are needed to better clarify the spectrum of these viral infections and develop effective prevention and treatment strategies. Yet the increased use of agents like alemtuzumab that induce profound T-cell depletion demands that we develop a better understanding of viral infections that occur in patients with hematological malignancy who receive nontransplant therapy.

T Cell Control of Primary and Latent Cytomegalovirus Infections in Healthy Subjects

The T cell repertoire required to control acute and latent CMV infection in otherwise healthy individuals was examined using both functional analysis and a wide range of MHC I tetramers. Both frequency and function of CMV specific T cells varied considerably between subjects, however, within subjects values remained stable over time. In total 16 +/- 3.5 CMV specific T cells/mul blood was detected, with obvious immunodominance between different CMV epitopes. Most subjects with latent infection showed low CMV specific T cell activity, whereas a subgroup (1/3) of individuals was high in either frequency or function of their CMV specific T cells. Patients with acute infection displayed high initial, but rapidly decreasing, numbers of CMV specific cells. In conclusion, a majority of healthy individuals readily seem to control latent CMV infection, whereas a subpopulation (1/3) of individuals uses a large proportion of their CD8+ T cell repertoire to control the infection.

Infliximab does not activate replication of lymphotropic herpesviruses in patients with refractory rheumatoid arthritis

The reactivation of human lymphotropic herpesviruses can be related to the intensity of immunosuppression. We analysed the risk of reactivation of lymphotropic herpesviruses in patients with refractory rheumatoid arthritis treated with an anti-tumour necrosis factor-alpha (TNF-alpha) agent (infliximab). Fifteen patients were treated with infliximab (3 mg/kg) at weeks 0, 2 and 6. Samples of both plasma and peripheral blood mononuclear cells (PBMC) were obtained before treatment (week 0) and before each infusion at weeks 2 and 6. Samples were analysed using a multiplex qualitative polymerase chain reaction (PCR) for lymphotropic herpesviruses. Quantification of cytomegalovirus (CMV) viral load (copies/ml) was performed using quantitative PCR. Reactivation was defined as the presence of viral DNA in plasma. Latent infection was defined as the presence of viral DNA in PBMC samples but not in plasma. On baseline, latent CMV infection was detected in eight patients (53.3%), human herpesviruses-6 (HHV-6) in two (13.3%), Epstein-Barr virus (EBV) in seven (46.6%), CMV + HHV-6 in one (6.6%), CMV + EBV in two (13.3%) and HHV-6 + EBV in one (6.6%). Viral reactivation related to infliximab treatment was not observed. There was only one patient who had HHV-6 reactivation, but this was already detected in the baseline sample. Infliximab treatment does not induce replication of human lymphotropic herpesviruses in patients with rheumatoid arthritis. Thus, herpesviruses prophylaxis would not be indicated in these patients.

γδ T cells take on CMV

Latent cytomegalovirus (CMV) infection can reactivate in patients undergoing immunosuppression after organ transplant. But γδ T cells escape immunosuppression and are free to take control of the infection, suggest Halary and colleagues on page 1567. These CMV-reactive γδ T cells also recognized intestinal epithelial tumor cell lines, suggesting that CMV-infected cells and tumor cells may share a common, as yet undefined, γδ T cell antigen. Figure A CMV-specific γδ T cell clone (4-29) produces TNF in response to tumor epithelial cell lines, but not normal epithelial cell lines. γδ T cells are a heterogeneous population of T cells that express a restricted T cell receptor repertoire and, unlike conventional αβ T cells, can be activated in a major histocompatibility complex (MHC)-independent fashion by self-antigens. Most subsets of γδ T cells reside in epithelial tissues such as the skin and intestine. Studies in mice have suggested that these cells are required for the control of various viral and bacterial infections, but precise roles for γδ T cells in humans have been difficult to establish. In previous work, this group noted that a subset of γδ T cells expanded in kidney transplant patients, but only in those with active CMV infections. They now find that γδ T cell lines derived from transplant patients are indeed CMV-specific, as they could kill CMV-infected cells but not cells infected with other related viruses. In an interesting twist, many of the CMV-reactive γδ T cell lines also recognized epithelial tumor cell lines. Although the identity of the potentially shared ligand remains under investigation, the authors suspect a local stress-induced self-antigen, as CMV replication often occurs preferentially in epithelial cells. The authors suggest that γδ T cells may be uniquely able to respond to CMV. The virus-specific αβ T cells, which are abundant during primary infections in otherwise healthy individuals, will be crippled by posttransplant immunosuppression. But γδ T cells are not immunosuppressed, and can still attack CMV-infected cells.

A simplified strategy for clinical management of late cytomegalovirus infection after oral ganciclovir prophylaxis in renal recipients

Late cytomegalovirus disease after completion of prophylactic therapy occurs in 5-21% of renal allograft recipients within the first year post-transplantation. Identifying patients at risk for late infection is clinically difficult; prolonged cytomegalovirus (CMV) monitoring is costly and cumbersome as follow-up intervals lengthen. We performed a prospective 1 year study in 54 de novo renal recipients to assess the minimum CMV monitoring frequency for identifying patients at risk. CMV DNA PCR monitoring on the last day, and again 2 weeks after conclusion of oral ganciclovir prophylaxis, seemed sufficient for identifying recipients at risk for developing clinically relevant late CMV disease and for whom closer clinical follow-up is warranted.

Long-Term Cytomegalovirus Infection Leads to Significant Changes in the Composition of the CD8+T-Cell Repertoire, Which May Be the Basis for an Imbalance in the Cytokine Production Profile in Elderly Persons

In spite of the present belief that latent cytomegalovirus (CMV) infection drives CD8+ T-cell differentiation and induces premature immune senescence, no systematic studies have so far been performed to compare phenotypical and functional changes in the CD8+ T-cell repertoire in CMV-infected and noninfected persons of different age groups. In the present study, number, cytokine production, and growth potential of naive (CD45RA+ CD28+), memory (CD45RA- CD28+), and effector (CD45RA+ CD28- or CD45RA- CD28-) CD8+ T cells were analyzed in young, middle-aged, and elderly clinically healthy persons with a positive or negative CMV antibody serology. Numbers and functional properties of CMVpp65(495-503)-specific CD8+ T cells were also studied. We demonstrate that aging as well as CMV infection lead to a decrease in the size of the naive CD8+ T-cell pool but to an increase in the number of CD8+ effector T cells, which produce gamma interferon but lack substantial growth potential. The size of the CD8+ memory T-cell population, which grows well and produces interleukin-2 (IL-2) and IL-4, also increases with aging, but this increase is missing in CMV carriers. Life-long latent CMV infection seems thus to diminish the size of the naive and the early memory T-cell pool and to drive a Th1 polarization within the immune system. This can lead to a reduced diversity of CD8 responses and to chronic inflammatory processes which may be the basis of severe health problems in elderly persons.

Risk factors for late cytomegalovirus infection after allogeneic stem cell transplantation using HLA-matched sibling donor: Donor lymphocyte infusion and previous history of early CMV infection

6648 Background: An increased incidence of late cytomegalovirus (CMV) infection has been reported during the last decade since the introduction of ganciclovir (GCV) prophylaxis or GCV pre-emptive t...

Risk factors for late cytomegalovirus infection after allogeneic stem cell transplantation using HLA-matched sibling donor: Donor lymphocyte infusion and previous history of early CMV infection

Risk factors for late cytomegalovirus infection after allogeneic stem cell transplantation using HLA-matched sibling donor: Donor lymphocyte infusion and previous history of early CMV infection

Risk factors for late cytomegalovirus infection after allogeneic stem cell transplantation using HLA-matched sibling donor: donor lymphocyte infusion and previous history of early CMV infection.

An increased incidence of late cytomegalovirus (CMV) infection has been reported during the last decade since the introduction of ganciclovir (GCV) prophylaxis or GCV pre-emptive therapy. Given that a donor lymphocyte infusion (DLI) can induce more severe GVHD, this may predispose a patient to late CMV infection. In all, 64 patients (median age 36, M/F 38/26) underwent allogeneic stem cell transplantation (SCT) using a matched sibling donor with bone marrow (n=9) or peripheral blood stem cells (n=55). The overall incidence of CMV infection, early and late CMV infection was 46.9 (30/64), 42.2 (27/64), and 16.4% (9/55), respectively. Early CMV infection was treated with GCV pre-emptive therapy that produced a 92.6% success rate. Among the 20 patients who received 35 DLIs, late CMV infection developed in eight (42.1%) of 19 evaluable cases with a median onset at 127 days post transplant. Risk factors for late CMV infection in a logistic regression analysis included DLIs (P=0.001) and a previous history of CMV infection (P=0.006). In conclusion, late CMV infection was strongly associated with DLIs and a previous history of early CMV infection. Accordingly, extended surveillance of CMV antigenemia is recommended for patients receiving DLIs or who have a previous history of CMV infection.

Clinical aspects of cmv infection after stem cell transplantation

Cytomegalovirus (CMV) infection is one of the most important infectious complications after stem cell transplantation (SCT). Major improvements in the management of CMV infection have been achieved during the last decade, including the introduction of safe blood product support for CMV-seronegative patients, the development of early pre-emptive antiviral therapy based on sensitive diagnostic tests, and antiviral prophylaxis. With the better control of CMV infection during the first 100 days after allogeneic SCT an increase in the incidence of CMV infection and disease after day 100 after transplantation was observed. New methods that allow for the reconstitution of CMV-specific immune responses such as adoptive T-cell therapy are promising tools that might help to improve the management of late CMV infection and disease.

Impact of human cytomegalovirus latent infection on myeloid progenitor cell gene expression.

Herpesviruses establish lifelong latent infections in their hosts. Human cytomegalovirus (CMV) targets a population of bone marrow-derived myeloid lineage progenitor cells that serve as a reservoir for reactivation; however, the mechanisms by which latent CMV infection is maintained are unknown. To gain insights into mechanisms of maintenance and reactivation, we employed microarrays of approximately 26,900 sequence-verified human cDNAs to assess global changes in cellular gene expression during experimental CMV latent infection of granulocyte-macrophage progenitors (GM-Ps). This analysis revealed at least 29 host cell genes whose expression was increased and six whose expression was decreased during CMV latency. These changes in transcript levels appeared to be authentic, judging on the basis of further analysis of a subset by semiquantitative reverse transcription-PCR. This study provides a comprehensive snapshot of changes in host cell gene expression that result from latent infection and suggest that CMV regulates genes that encode proteins involved in immunity and host defense, cell growth, signaling, and transcriptional regulation. The host genes whose expression we found altered are likely to contribute to an environment that sustains latent infection.