A longitudinal study of the serological and virological status of 18 women infected with cytomegalovirus

New approach and new permutation tests with R programs for analyses of false-negative-contaminated data in medicine and biology

Statistically, the concentration of antibodies against parasites decreases with the duration of infection. This can result in false-negative outcomes of diagnostic tests for subjects with old infections. When a property of seronegative and seropositive subjects is compared under these circumstances, the statistical tests can detect no difference between these two groups of subjects, despite the fact that they differ. When the effect of the infection has a cumulative character and subjects with older infections are affected to a greater degree, we may even get paradoxical results of the comparison - the seropositive subjects have, on average, a higher value of certain traits despite the infection having a negative effect on those traits. A permutation test for the contaminated data implemented, e.g. in the program Treept or available as a comprehensibly commented R function at https://github.com/costlysignalling/Permutation_test_for_contaminated_data, can be used to reveal and to eliminate the effect of false negatives. A Monte Carlo simulation in the program R showed that our permutation test is a conservative test - it could provide false negative, but not false positive, results if the studied population contains no false-negative subjects. A new R version of the test was expanded by skewness analysis, which helps to estimate the proportion of false-negative subjects based on the assumption of equal data skewness in groups of healthy and infected subjects. Based on the results of simulations and our experience with empirical studies we recommend the usage of a permutation test for contaminated data whenever seronegative and seropositive individuals are compared.

Differences in cognitive functions between cytomegalovirus-infected and cytomegalovirus-free university students: a case control study

Cytomegalovirus (CMV) is the herpetic virus, which infects 45–100% people worldwide. Many reports suggest that CMV could impair cognitive functions of infected subjects. Here we searched for indices of effects of CMV on infected subjects’ intelligence and knowledge. The Intelligence Structure Test I-S-T 2000 R was used to compare IQ of 148 CMV-infected and 135 CMV-free university students. Infected students expressed higher intelligence. Paradoxically, their IQ decreased with decreasing concentration of anti-CMV antibodies, which can be used, statistically, as a proxy of the time passed from the moment of infection in young subjects when the age of subjects is statistically controlled. The paradox of seemingly higher intelligence of CMV infected subjects could be explained by the presence of the subpopulation of about 5–10% CMV-positive individuals in the population of “CMV-negative students”. These false negative subjects had probably not only the oldest infections and therefore the lowest concentration of anamnestic antibodies, but also the lowest intelligence among the infected students. Prevalence of CMV infection in all countries is very high, approaching sometimes 90%. Therefore, the total impact of CMV on human intelligence may be large.

Review of cytomegalovirus shedding in bodily fluids and relevance to congenital cytomegalovirus infection

Congenital cytomegalovirus (CMV) infections are a leading cause of sensorineural hearing loss (SNHL) and neurological impairment. Congenital transmission of CMV can occur with maternal primary infection, reactivation, or reinfection during pregnancy. We reviewed studies of CMV shedding in bodily fluids (defined as CMV detected by culture or CMV DNA detected by polymerase chain reaction). Following diagnosis at birth, children with congenital CMV infection exhibited the highest prevalences of CMV shedding (median = 80%, number of sample population prevalences [N] = 6) and duration of shedding, with a steep decline by age five. Healthy children attending day care shed more frequently (median = 23%, N = 24) than healthy children not attending day care (median = 12%, N = 11). Peak shedding prevalences in children occurred at 1-2 years of age, confirming that young children are the key transmission risk for pregnant women. CMV shedding among children was more prevalent in urine specimens than in oral secretions (median prevalence difference = 11.5%, N = 12). Adults with risk factors such as STD clinic attendance had higher shedding prevalences (median = 22%, N = 20) than adults without risk factors (median = 7%, N = 44). In adults with risk factors, CMV was shed more frequently in urine; in adults without risk factors genital shedding was most common. The prevalence of CMV shedding in nine sample populations of pregnant women increased with advancing gestation. In seven sample populations of children with congenital CMV infection, higher viral load at birth was consistently associated with an elevated risk of SNHL. Higher CMV viral load at birth also consistently correlated with the presence of symptoms of congenital CMV at birth. Published 2011. This article is a US Government work and is in the public domain in the USA.

Cytomegalovirus (CMV) shedding is highly correlated with markers of immunosuppression in CMV-seropositive women

Cytomegalovirus (CMV) enters latency following primary infection and can subsequently reactivate. Reinfection with a different viral strain can also occur. During these events, CMV is shed in bodily fluids. This study examined correlates of CMV shedding in specimens obtained from the HIV Epidemiology Research Study, a multicenter cohort study of US women with or at high risk for human immunodeficiency virus (HIV) infection. Among the women studied, 91.4 % (911/997) were CMV IgG seropositive. Of these women, 2.7 % (25/911) were CMV IgM seropositive. CMV DNA was detected via real-time PCR more frequently in cervicovaginal lavage (CVL) specimens (55/764, 7.2 %) than in peripheral blood mononuclear cells (PBMCs) (26/897, 2.9 %). CMV viral loads in 1 ml CVL (median 534; mean 2598; range = 40-74, 844) were higher than in 10⁶ PBMCs (median 264; mean 1287; range = 35-13 ,250). CMV DNA in PBMCs was associated with HIV seropositivity [odds ratio (OR) 13.5; 95 % confidence interval (CI) 1.8-100], increasing HIV viral load (P<0.001 for trend), decreasing CD4 cell counts (P<0.001 for trend) and CMV DNA in CVL (OR 26; 95 % CI 10.7-64). CMV DNA in CVL specimens was associated with CMV IgM seropositivity (OR 4.3; 95 % CI 1.5-12.3), HIV seropositivity (OR 7.3; 95 % CI 2.6-20), increasing HIV viral load (P<0.001 for trend) and decreasing CD4 cell counts (P<0.001 for trend). The positive predictive value of CMV IgM seropositivity for CMV DNA shedding in either PBMCs or CVL was 20 %. In summary, CMV shedding in CVL and PBMCs was highly correlated with each other and with markers of immune suppression.

Comparison of shell viral culture and serology for the diagnosis of human cytomegalovirus infection in neonates and immunocompromised subjects

The present retrospective study compares the laboratory diagnosis of cytomegalic inclusion disease (CID) by the use of "shell vial culture" [i.e., immunoperoxidase staining of human cytomegalovirus (HCMV) early antigen in human fibroblasts 24 h postinoculation] to the results of serology (i.e. immunoglobulins IgG, IgM, and IgA HCMV antibody testing) in 21 infants with congenital or postnatally acquired HCMV infection, 5 patients with lymphoproliferative disorders, 35 human immunodeficiency virus (HIV)-seropositive patients who met the Centers for Disease Control (CDC) criteria for stages IVA and IVB of HIV infection, and 115 patients suffering from the acquired immunodeficiency syndrome, AIDS (stages IVC-IVE according to CDC criteria). HCMV infection was diagnosed by means of the shell vial culture inoculated with patient samples (e.g., urine, bronchoalveolar lavage, induced sputum, etc.) and serology in 163 (92.6%) and 65 (36.9%) patients, respectively. Viral shedding was detected by shell vial culture in 100% of the neonates, 80% of the patients suffering from lymphoproliferative disorders, 100% of the AIDS related complex (ARC) and 89.6% of the AIDS patients. In contrast, serologic testing for HCMV-specific antibodies was positive in only 28.6%, 42.9%, and 34.8% of the neonates, ARC, and AIDS patients, respectively. In lymphoma patients, serologic testing gave identical results (80%) to the shell vial culture technique. With the use of the shell vial procedure, active HCMV infection in immunocompromised subjects and neonates can be recognized more reliably than by serologic testing. Nevertheless, in a low percentage of patients (7.4%), virus isolation by the shell vial culture may fail to detect HCMV infection.

Screening of blood donors for cytomegalovirus (CMV) antibodies: an evaluation of different tests

The incidence of transfusion-associated cytomegalovirus (CMV) infections is related to the number of donors and the volume of blood. In immunosuppressed patients primary CMV infection is associated with a high morbidity and/or mortality. These infections can be prevented by the use of CMV negative blood products. A test for screening of CMV antibodies should have a high sensitivity and specificity and in addition be rapid and easily automated. In the present study the routine method in the laboratory, a CMV ELISA using a nuclear CMV antigen, was compared with Vironostika CMV anti-IgG MicroELISA, CMVSCAN, a latex agglutination test and a new ELISA from Organon Teknika, Vironostika CMV one-step MicroELISA. Sera from 419 blood donors were tested by all four tests. Discordant results were resolved by Western blot analysis using a glycine-extracted CMV antigen. The sensitivity was 100% for CMV ELISA and CMVSCAN and 99 and 96% for the CMV anti-IgG and CMV one-step tests respectively. The specificity was 100, 99, 94 and 100%, respectively. The ELISAs are suitable for screening of large numbers of serum samples and the CMV one-step test in particular was rapid and easy to perform although the sensitivity has to be increased. The latex agglutination test has the advantage of being extremely rapid.

Antibody response against early antigens in Herpesviridae infections

For the serological diagnosis of Herpesvirus infection, increasing use is made of the determination of the antibodies against virus-specific early antigens. The presence of serum antibody to early antigens is a widely accepted marker of acute Epstein-Barr virus infection or Varicella-Zoster virus infection. Controversial data are present in the literature about the significance of Cytomegalovirus early antigens antibody response. This is discussed in view of the possibility that controversial results could be due to different methods used to produce early antigens by different authors.

The immune response to human cytomegalovirus-induced early nuclear and early membrane antigens and its possible clinical significance

Before replication of the human cytomegalovirus (HCMV) genome takes place, two major antigenic complexes are induced in the infected cell by an early expression of parental viral genome: one (Early antigen or EA) is localised in the nucleus, the other (Early membrane antigen or EMA) on the plasma-membrane. Sequential samples of serum from renal transplant recipients, pregnant women, blood donors and patients with known HCMV disease were examined by means of indirect immunofluorescence tests for the presence of IgG, IgM and IgA antibodies against EA and EMA. Serum antibody reacting with EMA belongs almost exclusively to the IgM class while that reacting with EA may be of the IgG, IgM or IgA class. IgM antibody to EMA seems to be preferentially associated with primary active HCMV infection.

Cytomegalovirus-specific cell-mediated immunity in lower-socioeconomic-class adolescent women with local cytomegalovirus infections

The factors that regulate cytomegalovirus (CMV) excretion from the genitourinary tract are poorly understood. To assess the role of cell-mediated immunity in such excretion, a CMV-specific mononuclear blastogenesis assay was used to study a predominantly lower-socioeconomic-status population of 92 healthy nonpregnant adolescent women who also had CMV complement-fixing antibody titers and viral cultures of cervix, urine, saliva, and blood performed. Eighteen were studied more than once. No blood cultures were positive and no seroconversions were noted. There was no significant difference for frequency or degree of systemic CMV-specific blastogenesis between the 20 who were culture positive and the 41 who were seropositive but culture negative, although 40% of the culture-positive group and 27% of the seropositive, culture-negative group lacked CMV-specific blastogenesis. One of 31 seronegative subjects displayed CMV-specific blastogenesis. No systematic deficits were noted in any groups or individuals for E rosette number or mitogen response, though some isolated significant differences among groups for mitogen responses existed. Local CMV excretion in the study population was not related to systemic CMV-specific mononuclear blastogenesis.

Prenatal screening of pregnant women for infections caused by cytomegalovirus, Epstein-Barr virus, herpesvirus, rubella, and Toxoplasma gondii

A service-oriented screening program for serologic detection of viral and parasitic infections during gestation is described for three different population groups. Significance of a determination of primary cytomegalovirus infection is documented. A screening program for detection of immunity to rubella is recommended, but the feasibility of similar programs for herpes simplex virus and Epstein-Barr virus warrants further study. Because of the low frequency of toxoplasmosis, education of patients instead of screening may be appropriate.

Cytomegalovirus-infected cell polypeptides immune-precipitated by sera from children with congenital and perinatal infections

Congenital or perinatally acquired human cytomegalovirus (CMV) infections in children may be symptomatic or asymptomatic. In this study, we characterized the electrophoretic properties of CMV-infected cell polypeptides immune-precipitated by sera from children with different types of CMV infections from birth to 4 years of age. Sodium dodecyl sulfate-polyacrylamide gel analysis of immune precipitates formed with radiolabeled extracts of cells infected with CMV strain AD169 showed the following. (i) Electrophoretic profiles of CMV polypeptides immune-precipitated by sera from children with perinatal and congenital infections were similar. At least 11 polypeptides with apparent molecular weights of 150,000, 140,000, 110,000, 100,000, 74,000, 66,000, 50,000, 49,000, 34,000, 25,000, and 20,000 were precipitated. Antibody titer in anticomplement immunofluorescence tests and virus titer in urine correlated with the intensity of polypeptide profiles in autoradiograms. (ii) The initial immune response of children with symptomatic congenital infections was delayed as compared to that of children with asymptomatic congenital and perinatal CMV infections. Sera obtained serially from symptomatic children for years after birth continued to precipitate CMV polypeptides, whereas sera from children with subclinical congenital infections precipitated lesser amounts over time. (iii) Immune precipitates obtained with sera from CMV-infected patients and with monoclonal antibodies to CMV contained polypeptides with comparable electrophoretic and immunological properties.

Congenital cytomegalovirus infection: The relative importance of primary and recurrent maternal infection

We studied the incidence of primary and recurrent cytomegalovirus infection in 3712 pregnant women--2698 of middle to high income and 1014 of low income--to determine whether there were differences in the effects on the fetus. In the higher-income group, 1203 women (45 per cent) did not have antibodies to cytomegalovirus and were therefore susceptible to primary infection, as compared with 179 women (18 per cent) of low income. Congenital infection occurred more often (1.6 vs. 0.6 per cent) in infants in the low-income group. In this group it was associated with recurrent maternal infection more often (in 82 per cent) than with primary maternal infection, whereas in the upper-income group, it was associated with primary maternal infection in half the cases. Altogether, there were 32 cases of congenital cytomegalovirus infection - 16 in each group. Whereas primary maternal infection resulted in fetal infection in only half the cases, it was more likely to ge associated with clinically apparent disease than was recurrent infection. When these cases were combined with 28 cases of congenital infection retrospectively identified at other prenatal clinics, five of 33 infected infants born after primary maternal infection had clinically apparent disease, as compared with none of 27 born after recurrent maternal infection. We conclude that congenital cytomegalovirus infection resulting from primary maternal infection is more likely to be serious than that resulting from recurrent infection, and is more likely to occur in upper socioeconomic groups.

A comparison of cervical cytomegalovirus (CMV) excretion in gynaecological patients and post-partum women

CMV was isolated from the cervix of 4.2 per cent of 191 gynaecological patients and from 9.8 per cent of 51 women post-partum; all patients were attending the same general practice clinic. The CMV excretion rate was particularly high in the early post-partum period decreasing to nearly normal levels as menstruation returned. Three of 14 (21.4 per cent) post-partum patients excreted CMV before menses had restarted whereas virus was isolated from only two of 36 (5.6 per cent) women who had returned to a normal menstrual cycle. Although this difference was not statistically significant, the excretion rate early post-partum was significantly higher than in the gynaecological group (p less than 0.05). Five of seven excretors in the gynaecological group were in the first half of a menstrual cycle at the time of virus isolation thus suggesting that hormonal changes may lead to CMV reactivation in the genital tract. Other factors which may influence the presence of CMV in the genital tract of non-pregnant women are discussed. Three of four infant born to women excreting virus on the cervix post-partum became infected with CMV.

Persistence of high titre antibodies to the early antigens of cytomegalovirus in pregnant women

Serial serum samples were obtained from 45 pregnant women who had been shown to possess complement fixing (CF) antibodies to cytomegalovirus (CMV) during a previous pregnancy. The serial samples were tested for antibodies against the early antigens (EA) and complement fixing antigens of CMV. All of the 45 women still possessed CF antibodies at the commencement of their next pregnancy. Six of the 45 women (13 per cent) lacked detectable IFA-EA antibodies whilst 19/45 (42 per cent) women possessed only low titres (less than or equal to 64) of these antibodies. However, 20/45 (44 per cent) women possessed high titre (greater than or equal to 128) antibodies despite having experienced their primary CMV infection many months previously. It is concluded that antibodies to the EA OF CMV are not as transitory as has been suggested and that their presence, even at high titre, in a serum sample from a pregnant woman cannot be taken as presumptive evidence of recent primary infection with this virus.