Spotlight on NKG2C and the human NK‐cell response to CMV infection

Immune responses to cytomegalovirus (CMV) infection in the mouse and human involve the expansion of specific subsets of natural killer (NK) cells with specific phenotypic characteristics and a heightened ability to produce interferon (IFN)‐gamma. In humans, these NK‐cell responses are largely driven by the activating receptor NKG2C, which recognize human leukocyte antigen (HLA)‐E in complex with leader sequence peptides. In this issue of the European Journal of Immunology, Noyola et al. [Eur. J. Immunol. 2012, 42: 3256‐3266] examine NK‐cell responses in a unique cohort of young children with asymptomatic and symptomatic congenital CMV infection. They also address NK‐cell responses to CMV in relation to NKG2C gene copy number. Children with a symptomatic congenital infection exhibited a marked expansion of NKG2C⁺ NK cells. However, despite having slightly lower frequencies of NKG2C⁺ NK cells, children with a heterozygous deletion of the NKG2C gene seemed to control the virus as efficiently as those with two copies of the NKG2C gene. The present studies shed new light on the role of NKG2C copy number variation on the human NK‐cell response to CMV infection.     

Relation of maternal CMV viremia and antibody response to the rate of congenital infection and intrauterine growth retardation

Pregnancy outcome after maternal primary CMV infection initiated at different times during gestation was investigated by using the inbred Strain-2 guinea pig model of congenital CMV infection. The highest vertical transmission rates occurred in pups from dams that were initially viremic in late gestation presumably because delivery occurred prior to detectable maternal CMV-specific immune response. In contrast, conceptus loss was highest with maternal CMV infection initiated at conception. Intrauterine resorptions, intrauterine growth retardation, and disseminated neonatal CMV infection with CNS involvement were more frequent in pups born to mothers that were initially viremic prior to rather than after midgestation. Maternal viremia was prolonged and antibody responses were delayed after CMV inoculation in early gestation compared to late gestation. Prolonged maternal viremia plus early gestational virus exposure/infection of the fetus appeared to be associated with the most severe outcome. These findings suggest that the timing of initial maternal viremia and immune responses, the stage of fetal development, and the length of in utero exposure to CMV are important factors in subsequent disease expression and rates of congenital infection.     

Asymptomatic CMV infections in long‐term renal transplant recipients are associated with the loss of FcRγ from LIR‐1+ NK cells

While it is established that cytomegalovirus (CMV) disease affects NK‐cell profiles, the functional consequences of asymptomatic CMV replication are unclear. Here, we characterize NK cells in clinically stable renal transplant recipients (RTRs; n = 48) >2 years after transplantation. RTRs and age‐matched controls (n = 32) were stratified by their CMV serostatus and the presence of measurable CMV DNA. CMV antibody or CMV DNA influenced expression of NKG2C, LIR‐1, NKp30, NKp46, and FcRγ, a signaling adaptor molecule, on CD56^dim NK cells. Phenotypic changes ascribed to CMV were clearer in RTRs than in control subjects and affected NK‐cell function as assessed by TNF‐α and CD107a expression. The most active NK cells were FcRγ^–LIR‐1⁺NKG2C^– and displayed high antibody‐dependent cell cytotoxicity responses in the presence of immobilized CMV glycoprotein B reactive antibody. However, perforin levels in supernatants from RTRs with active CMV replication were low. Overall we demonstrate that CMV can be reactivated in symptom‐free renal transplant recipients, affecting the phenotypic, and functional profiles of NK cells. Continuous exposure to CMV may maintain and expand NK cells that lack FcRγ but express LIR‐1.     

CMV drives the expansion of highly functional memory T cells expressing NK‐cell receptors in renal transplant recipients

Cytomegalovirus (CMV) is a common opportunistic infection encountered in renal transplant recipients (RTRs) and may be reactivated without symptoms at any time post‐transplant. We describe how active and latent CMV affect T‐cell subsets in RTRs who are stable on maintenance therapy. T‐cell responses to CMV were assessed in RTRs (n = 54) >2 years post‐transplant, and healthy controls (n = 38). Seven RTRs had CMV DNA detectable in plasma. CMV antibody and DNA aligned with increased proportions of CD8⁺ T cells and reduced CD4/CD8 ratios. This paralleled an expansion of effector memory T‐cell (T_EM), terminally differentiated T‐cell (T_EMRA) and CD57⁺ T_EMRA cell populations. Expression of NK‐cell receptors, LIR‐1 and KLRG1 on CD4⁺ and CD8⁺ CD57⁺ T_EM and T_EMRA cells correlated with elevated interferon‐γ and cytotoxic responses to anti‐CD3 and increased cytotoxic responses to CMV phosphoprotein (pp) 65 in RTRs who carried CMV DNA. CD8⁺ T cells from all CMV seropositive RTRs responded efficiently to CMV immediate early (IE) ‐1 peptides. The data show that latent and active CMV infection can alter T‐cell subsets in RTRs many years after transplantation, and up‐regulate T‐cell expression of NK‐cell receptors. This may enhance effector responses of CD4⁺ and CD8⁺ T cells against CMV.     

Cytomegalovirus seroconversion rates and risk factors: implications for congenital CMV

Congenital CMV infection is caused by in utero mother‐to‐fetus transmission and is a leading cause of birth defects and developmental disabilities. The highest risk of disability is to children born to women who have a primary infection during pregnancy, which can be detected by measuring seroconversion. We reviewed studies that reported rates of CMV seroconversion in different populations. Among pregnant women, annual seroconversion rates typically ranged from 1 to 7% (summary annual rate = 2.3%, 95% CI = 2.1–2.4%). Healthcare workers, including those caring for infants and children, had seroconversion rates similar to pregnant women (summary annual rate = 2.3%, 95% CI = 1.9–2.9%). Among day‐care providers, seroconversion rates ranged from 0 to 12.5% (summary annual rate = 8.5%, 95% CI = 6.1–11.6%). Parents whose child was not shedding CMV were much less likely to seroconvert (summary annual rate = 2.1%, 95% CI = 0.3–6.8%) than were parents who had a child shedding CMV (summary annual rate = 24%, 95% CI = 18–30%). Nevertheless, over the course of a year, most parents exposed to a CMV‐shedding child do not become infected. Other groups with elevated risk included families with a CMV‐shedding member, female minority adolescents and women attending sexually transmitted disease clinics. The relatively low rate of CMV seroconversion in most populations is encouraging for behavioural interventions and for vaccine strategies attempting to prevent infection during pregnancy. Published in 2010 by John Wiley & Sons, Ltd.     

Evaluation of Murex CMV DNA Hybrid Capture Assay for Detection and Quantitation of Cytomegalovirus Infection in Patients following Allogeneic Stem Cell Transplantation

Murex hybrid capture DNA assay (HCS) is a solution hybridization antibody capture assay for detection and quantitation of cytomegalovirus (CMV) DNA in leukocytes. To determine whether CMV HCS is sensitive enough to initiate and monitor antiviral therapy after allogeneic stem cell transplantation (SCT), 51 consecutive SCT recipients were prospectively screened for the appearance of CMV infection by HCS, PCR, and culture assays from blood samples. Preemptive antiviral therapy was initiated after the second positive PCR result in all patients, as previously reported, and HCS was not considered for clinical decision making. A total of 417 samples were analyzed. Of these, 21 samples were found to be positive by PCR and HCS, 88 samples were PCR positive but HCS negative, and 308 were negative by both assays. Concordance of results between PCR and HCS and between HCS and blood culture was observed in 78.9 and 95.9% of the samples assayed, respectively. PCR was found to be more sensitive than HCS, and HCS was more sensitive than the blood culture assay (P < 0.0001). Four patients with symptomatic CMV infection were PCR positive prior to the onset of CMV-related symptoms, whereas HCS detected CMV DNA in three patients prior to and one at onset of CMV disease. The numbers of genomes per milliliter of blood were higher in patients with symptomatic CMV infection than in those with asymptomatic CMV infection (P = 0.06). None of the HCS-negative patients developed CMV disease. Thus, all patients with CMV disease were correctly identified by HCS; however, the lower sensitivity limit of the HCS assay may still be insufficient to allow diagnosis of CMV infection early enough to prevent CMV disease in patients following allogeneic SCT.     

Cytomegalovirus infection in day care centres: A systematic review and meta‐analysis of prevalence of infection in children

Maternofetal transmission of cytomegalovirus (CMV) is the most common infectious cause of congenital malformation in developed countries. Maternal infection often results from close contact with infected children, and this may occur in day care centres (DCCs). A systematic review of observational studies was conducted to examine the prevalence of CMV infection among children attending DCCs. Meta‐analysis using the random effect model was performed for studies including controls. Sources included PubMed, EMBASE (until August 2018), and references from identified publications. Inclusion criteria were studies reporting CMV infection prevalence among childcare children aged less than 7 years of age. Controls were children without childcare exposure. CMV infection was defined as viral excretion detected by culture, polymerase chain reaction, or CMV seropositivity. Twenty‐eight publications including 8347 participants met the eligibility criteria. The pooled prevalence of CMV infection among children in childcare from all studies was 32% (95% CI 23‐41). Within case‐controlled studies, prevalence among children attending DCCs was 34% (95% CI 25‐44), whereas prevalence among those without childcare exposure was 22% (95% CI 15‐30). Meta‐analysis showed a significant association between DCC attendance and CMV infection (odds ratio 2.69, 95% CI 1.68‐4.30; heterogeneity χ²/df = 8; I² = 84%, P < 0.00001). Attendance at DCCs is significantly associated with increased risk of childhood CMV infection. Prevention strategies to reduce risk of CMV infection of pregnant women and children should involve review of DCC exposure and consideration of preventative hygiene strategies.     

Cytomegalovirus‐specific T cells are detectable in early childhood and allow assignment of the infection status in children with passive maternal antibodies

Serological identification of the cytomegalovirus (CMV) status in children less than 18 months of age is complicated by the variable persistence of maternal antibodies. As T cells are not passively transferred, we attempted to assess whether CMV‐specific cellular immunity may be superior to determine the actual CMV status; we also performed a functional characterization of T‐cell immunity in childhood. Antibodies from 59 mothers and 168 children were determined, and specific CD4⁺ T cells were identified by induction of IFN‐γ, IL‐2, TNF‐α, IL‐4, and IL‐17 after CMV‐specific and polyclonal stimulation. Agreement between both tests was perfect for mothers and children more than 18 months. Among infants less than 18 months, 17/30 were concordantly negative. Interestingly, 8/13 seropositive children had detectable CMV‐specific T cells, whereas only 5/13 were T‐cell negative, indicating passive immunity. CMV‐specific T cells from young infants differed in cytokine profiles from that of older age groups, and polyclonal effector T‐cell frequencies were higher in young infants with detectable CMV‐specific T cells compared with those without. In conclusion, the majority of young infants with CMV‐specific antibodies show evidence of true infection, which indicates that passive immunity is overestimated. Our data may have important implications for improved risk stratification and CMV management in infants in the setting of transplantation.     

The value of CMV IgG avidity and immunoblot for timing the onset of primary CMV infection in pregnancy

BackgroundPrimary CMV infections in pregnancy are usually asymptomatic and only detected by serology. Estimating the onset of infection is a major diagnostic goal, since primary infections around conception and in early gestation hold a higher risk for congenital disease than those in later pregnancy.ObjectivesTo assess the ability of serological supplementary CMV assays to date the onset of primary infection.Study designFrom our routine diagnosis we identified 61 pregnant women (n = 188 serum samples) with precisely determined onset of CMV primary infection either by IgG seroconversion (n = 24) or by significant IgG antibody rise (n = 37). One hundred and forty-seven sera were investigated using the VIDAS^® CMV IgG avidity EIA (BioMèrieux) and 83 sera using the recomBlot CMV IgG with avidity (Mikrogen).ResultsBoth assays proofed to be reliable in terms of timing the onset of CMV primary infection. An avidity index (AI) in the VIDAS avidity EIA of <40% indicated primary infection within the last 20 weeks (positive predictive value 93.4%; 99/106), whereas an intermediate AI excluded primary infection within the last 12 weeks (negative predictive value 88.2%; 15/17). The recomBlot showed high reliability (PPV 96.9%; 31/33) for timing the onset of infection within the last 14 weeks. Avidity testing by blot however could not be interpreted in 11 of 47 sera (23.4%).ConclusionFor timing the onset of infection (before or in early pregnancy) CMV avidity testing is most helpful if carried out within the first trimester up to the beginning of second trimester.     

Seroprevalence and serum profile of cytomegalovirus infection among patients with hematologic disorders in Bahia State, Brazil

Human cytomegalovirus (CMV) is a ubiquitous herpesvirus with from 30% to 100% of the general population exhibiting prior exposure by serology. This cross‐sectional study evaluated the serological profile of anti‐CMV antibodies and two acute‐phase reaction proteins in Haematologic Disorder Patients (HDPs) from Bahia State, Brazil. Immuno‐chemiluminescence assays were performed to detect anti‐CMV IgM and IgG antibodies. Serological levels of High Sensitivity C‐Reactive Protein (CRPH) and Alpha‐1‐Acid Glycoprotein (AAG) were measured using immunonephelometry. A total of 470 HDPs were enrolled, 238 (50.6%) males and 232 (49.4%) females. The overall seroprevalence of CMV was 89.4%, directly proportional to age and to the amount of blood units transfused. There was no difference between seroprevalence rates according to gender (P = 0.12). Four HDPs (0.9%) were seropositives for anti‐CMV IgM, only one could be characterized as recent acute infection. The most CMV seropositive HDPs had anti‐CMV IgG in low titers. There was a tendency for females to have higher anti‐CMV IgG titers than men (P < 0.05). CRPH levels were different among HDPs CMV negative and positive groups (P < 0.001). There was no difference in the AAG levels between groups (P = 0.15). The high CMV seroprevalence found underscores the importance of using strategies to provide “CMV safe” blood to HDPs who are at high risk of developing severe CMV infection. CRPH can be used as a biomarker associated with CMV seropositivity; however, more efforts are needed to better characterize the clinical profile of active CMV infection in this group of patients. J. Med. Virol. 83:298–304, 2011. © 2010 Wiley‐Liss, Inc.     

Low maternal CD4 count at inception of gestational cytomegalovirus (CMV) infection and impaired humoral response: effect on congenital CMV infection in the guinea pig.

In humans, the rate and clinical expression of disease in congenitally cytomegalovirus (CMV)-infected infants is modified by maternal immunity to CMV. We used the guinea pig model of congenital CMV infection to compare maternal CD4+ T-cell numbers in nonpregnant animals to those in pregnant dams just before and 7-14 days after inoculation with guinea pig CMV (gpCMV) very early, early, or late in gestation. We also examined ELISA antibody responses to gpCMV in the inoculated nonpregnant and pregnant animals. When compared to nonpregnant uninfected animals, CD4 counts were lower in very early and in late uninfected gestation. CD4 counts also dropped further in the postinoculation period. Compared to nonpregnant gpCMV-inoculated animals, initial antibody responses to gpCMV were also decreased in gpCMV-infected pregnant dams. The group of dams inoculated very early in pregnancy experienced delays in seroconversion to gpCMV, persisting low titers throughout gestation, in utero fetal resorptions, and CNS-infected pups. The group of dams inoculated late in gestation had the lowest geometric mean titers at delivery (almost 50% with no detectable antibody) and a high rate of vertical gpCMV transmission and postnatal pup death. Significantly lower rates of both congenital infection and postnatal pup deaths were observed in litters of late gestation-infected dams that had gpCMV antibody at delivery. Thus, decreased circulating maternal CD4+ T cells very early and late in gestation were further decreased after gpCMV inoculation and were associated with delayed and depressed maternal antibody responses, all of which were associated with poor outcome after primary maternal gpCMV infection, the expression of which varied by time in pregnancy when gpCMV was acquired.     

Maintenance of cytomegalovirus (CMV) latency and host immune responses of long term renal allograft survivors. I. Prolonged suppression of in vitro lymphocyte responses against CMV infected fibroblasts related to previous secondary CMV infection.

Cytomegalovirus (CMV) specific humoral and cellular immunity was investigated in 16 renal allograft recipients with long term graft survival (26-122 months) who were shown to be CMV seropositive before transplantation. Results were compared with healthy individuals with latent CMV infections. Recipients (n = 9) who experienced a symptomatic secondary CMV infection shortly after transplantation (less than 6 months), showed a prolonged but finally temporary suppression of their in vitro lymphocyte memory responses against CMV infected fibroblasts (CMV-FF; median SI: 1.9), a persistence of high antibody titres against intracellular CMV antigens and most of them also had antibodies against CMV membrane antigens (CMV MA). In contrast the recipients (n = 7) who could maintain their CMV in latency after transplantation, had lower antibody titres and their in vitro memory lymphocyte responses against CMV-FF (median SI: 9.3) were comparable to those of the healthy controls (median SI: 11.6). The memory lymphocyte responses against purified CMV virions were depressed in both recipient groups. These results suggest that cellular immunity against CMV infected target cells constitute an important mechanism in maintaining CMV in latency after allografting.     

Adoptive transfer of cytomegalovirus‐specific effector CD4+ T cells provides antiviral protection from murine CMV infection

Cytomegalovirus (CMV) infects a majority of the human population and establishes a life‐long persistence. CMV infection is usually asymptomatic but the virus carries pathogenic potential and causes severe disease in immunocompromised individuals. T‐cell‐mediated immunity plays an essential role in control of CMV infection and adoptive transfer of CMV‐specific CD8⁺ T cells restores viral immunity in immunosuppressed patients but a role for CD4⁺ T cells remains elusive. Here, we analyzed in adoptive transfer studies the features and antiviral functions of virus‐specific CD4⁺ T cells during primary murine CMV (MCMV) infection. MCMV‐specific CD4⁺ T cells expanded upon MCMV infection and displayed an effector phenotype and function. Adoptive transfer of in vivo activated MCMV‐specific CD4⁺ T cells to immune‐compromised mice was protective during pathogenic MCMV infection and IFN‐γ was a crucial mediator of this protective capacity. Moreover, co‐transfer of low doses of both MCMV‐specific CD4⁺ T cells and CD8⁺ T cells synergized in control of lytic viral replication in immune‐compromised mice. Our data reveal a pivotal antiviral role for virus‐specific CD4⁺ T cells in protection from pathogenic CMV infection and provide evidence for their antiviral therapeutic potential.     

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 outcome of congenital cytomegalovirus infection in relation to maternal antibody status.

BACKGROUND. Intrauterine transmission of cytomegalovirus (CMV) can occur whether a mother has prior immunity or acquires CMV for the first time during pregnancy. The degree of protection afforded an infected infant by the presence of antibody in the mother before conception is uncertain. METHODS. We compared the outcomes of CMV-infected infants born to mothers who acquired primary CMV infection during pregnancy (primary-infection group) with those of CMV-infected infants born to mothers with immunity (recurrent-infection group). Screening for viruria identified 197 newborns with congenital CMV infection. Stored serum samples were used to categorize maternal infection as either primary or recurrent. We followed 125 infants from the primary-infection group and 64 from the recurrent-infection group. Serial medical, audiologic, psychometric, and eye examinations were used to identify sequelae of CMV infection. RESULTS. Only infants in the primary-infection group had symptomatic CMV infection at birth (18 percent). After a mean follow-up of 4.7 years, one or more sequelae were seen in 25 percent of the primary-infection group and in 8 percent of the recurrent-infection group. Thirteen percent of infants whose mothers had primary infection during pregnancy had mental impairment (IQ less than or equal to 70), as compared with none of those whose mothers had recurrent CMV infections. Sensorineural hearing loss was found in 15 percent of those in the primary-infection group and in only 5 percent of those in the recurrent-infection group. Bilateral hearing loss was identified only among children in the primary-infection group (8 percent). CONCLUSIONS. The presence of maternal antibody to CMV before conception provides substantial protection against damaging congenital CMV infection in the newborn. Primary maternal infection during pregnancy is associated with more severe sequelae of congenital CMV infection.     

Evaluation of the new LIAISON® CMV IgG,IgM and IgG Avidity II assays

BackgroundThe diagnosis of CMV infection is challenging and the quality of serological laboratory testing is critical, especially in pregnancy and in the determination of transplant recipients and donors serostatus.ObjectivesEvaluate the performances of the new LIAISON^® CMV II line: LIAISON^® CMV IgG II, LIAISON^® CMV IgM II and LIAISON^® CMV IgG Avidity II in comparison with the routine methods used in our laboratory.Study designThe evaluation of LIAISON^® CMV IgG II and LIAISON^® CMV IgM II was performed on both prospective routine samples and retrospective selected samples for a total of 383 sera. CMV IgG avidity was assessed with 88 samples.ResultsThe overall agreement was 98.8% for the IgG and 95% for the IgM on the routine population. On selected retrospective samples, excellent agreement was found in the seronegative and past infection groups. In the recent infection group, discordances were observed in 7.1% of IgG and 13.1% of IgM. No recent infection was missed with LIAISON^®. Avidity agreement with VIDAS^® was 81%. On 51 sera with a known time of infection, no high avidity was found in the group infected for less than 3 months and 82% of the samples showed a high avidity in the group infected for more than 3 months.ConclusionThe performances of the fully automated LIAISON^® CMV II line assays are comparable to those of the reference methods used in our lab for both prospective and selected populations. This new CMV line is a useful tool for the diagnosis of CMV infections and CMV immune status in clinical settings     

Low Rate of CMV End-Organ Disease in HIV-Infected Patients Despite Low CD4+ Cell Counts and CMV Viremia: Results of ACTG Protocol A5030

Abstract

Purpose: To describe cytomegalovirus (CMV) end-organ disease (EOD) rate in AIDS patients with low CD4+ cell count despite HAART who were enrolled in a randomized, placebo-controlled trial of preemptive valganciclovir (VGCV) to prevent CMV EOD in those with CMV viremia. Methods: Subjects (N = 338) were HIV-infected with CD4+ count <100 cells/mm³, plasma HIV RNA >400 copies/mL, and on stable or no HAART. All underwent plasma CMV DNA PCR testing every 8 weeks (Step 1); those with detectable CMV DNA were randomized to VGCV or placebo (Step 2). Results: Plasma CMV DNA was detected in 68 (20%), of whom 4 developed CMV EOD. During Step 1, 53 died. Of the 47 who entered Step 2 (24 VGCV, 23 placebo), CMV EOD was diagnosed in 10 (4 VGCV, 6 placebo) and 15 died (7 VGCV, 8 placebo). Of those randomized to placebo, 14% were diagnosed with CMV EOD at 12 months. Conclusions: We observed a lower CMV EOD rate among subjects receiving HAART than predicted based on published literature. However, mortality was high in this study. Our findings suggest that preemptive anti-CMV therapy in patients with persistently low CD4+ cell counts in the current treatment era may not be warranted given the low incidence of CMV EOD and high all-cause mortality observed in this study population.     

Salivary cytomegalovirus excretion in children in daycare centers and home care facilities in Japan

Cytomegalovirus (CMV) is the most common cause of congenital viral infection in developed countries. The incidence of in utero infection is high in pregnant women who are CMV antibody negative. An important infection route is in contact with children who attend daycare centers (DCCs). However, there are few reports on CMV excretion in children at DCCs in Japan. Saliva samples were collected twice during a 6-month interval from children attending one of two DCCs (DCC1 and DCC2 groups) and from those receiving home care (HC group). The samples were used to quantitatively evaluate CMV using real-time polymerase chain reaction and to determine glycoprotein B (gB) genotypes. The percentage of subjects who demonstrated CMV excretion in either the first or second sample collection was higher in the DCC groups than in the HC group, with incidences in the DCC1, DCC2, and HC groups of 53.4% (n = 47 of 88), 23.9% (n = 16 of 67), and 12.7% (n = 7 of 55), respectively. Compared with the DCC2 group, the DDC1 group had a higher incidence of CMV excretion and included more subjects with a high number of viral copies. In both DCC groups, the incidence of CMV excretion was highest in children younger than 3 years of age. In all three groups, the predominant genotypes were gB1 and gB3. Based on the higher incidence of CMV excretion in the DCC groups compared with the HC group, it is considered that CMV infection is acquired mainly in DCCs in children under the age of 3.     

Distinguishing cytomegalovirus (CMV) infection and disease with CMV nucleic acid assays

Human cytomegalovirus (CMV) continues to be a significant cause of morbidity and mortality among transplant recipients. Molecular assays have been developed for the detection and quantification of CMV nucleic acid. In evaluating the clinical utility of these assays, correlations with clinical outcome are essential. The Amplicor CMV Monitor and NucliSens CMV pp67 tests were compared to the CMV antigenemia assay for 45 transplant recipients and 1 patient with Wegener's granulomatosis. Twenty-three patients remained antigenemia negative throughout the monitoring period, none of whom developed CMV disease. In this patient group, both the Amplicor and NucliSens assays showed very high specificity; only 1 of the 324 specimens assayed by NucliSens and none of the 303 specimens assayed by Amplicor were positive. Twenty-three patients were antigenemia positive during the monitoring period, 12 of whom developed 13 episodes of symptomatic CMV disease. In this patient group, the NucliSens assay was positive at or before the development of symptoms in 12 of the 13 episodes of CMV disease. All eight patients with symptomatic CMV disease who were tested by the Amplicor assay were positive at or before the development of disease. For the 11 asymptomatic patients, the NucliSens assay was positive less frequently than the antigenemia or Amplicor assays. The NucliSens assay was more likely to be positive at higher antigenemia or viral load levels. Both the NucliSens and Amplicor assays appear to have clinical utility in monitoring patients for CMV disease.     

Congenital cytomegalovirus infection following first trimester maternal infection: symptoms at birth and outcome.

BACKGROUND: The relationship between gestational age at time of maternal cytomegalovirus (CMV) infection and outcome of fetal infection is not well defined because the timing of maternal infection is usually not known. OBJECTIVE: To determine whether congenital cytomegalovirus (CMV) infection following primary maternal infection during the first trimester of pregnancy is more likely to lead to central nervous system (CNS) sequelae than fetal infection due to maternal infection later in pregnancy. STUDY DESIGN: Using serum collected during pregnancy from mothers of newborns with congenital CMV infection, maternal infection was categorized as first trimester (<13 weeks) or later based on dates and results of IgG and IgM assays for CMV antibody. Outcome of congenital CMV infection was assessed by longitudinal fotlow-up of the infected cohort. RESULTS: Sensorineural hearing loss was found in 8/34 (24%) of children in the first trimester group, compared with 1/40 (2.5%) in the later infection group (P=0.01, relative risk, 9.6). Considering any CNS sequela (hearing loss, mental retardation, cerebral palsy, seizures, chorioretinitis) 11/34 (32%) first trimester cases were affected compared with 6/40 (15%) in the later infection group (P=0.07, relative risk 2.2). None of the later group had more than one sequela, compared with 4 (12%) of the first trimester group (P=0.04). CONCLUSIONS: Children with congenital CMV infection following first trimester maternal infection are more likely to have CNS sequelae, especially sensorineural hearing loss, than are those whose mothers were infected later in pregnancy. However, some degree of CNS impairment can follow even late gestational infection.