Detection of human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) DNA in endocervical samples from a positive and negative HPV woman of Córdoba, Argentina.

AIMS: The purpose of the present study was to elucidate the presence of human herpesvirus 6A (HHV-6A), HHV-6B and HHV-7 in samples of the uterine cervix through detection of viral DNA. We analysed normal tissues, samples with low-grade squamous intraepithelial lesions (LSILs) and high-grade squamous intraepithelial lesions (HSILs). We correlated the presence of HHV-6 and HHV-7 with the finding of human papillomavirus (HPV) in mucosal samples. METHODS: Cervical samples were examined and grouped as follows: group 1 (n=29), normal cytology; group 2 (n=61), samples with LSIL; group 3 (n=35), samples with HSIL. Molecular biology examinations were performed in all samples to detect HHV-6, HHV-7 and HPV DNA and to typify HHV-6 species. RESULTS: Group 1: normal cytology and HPV (-): HHV-6: 6.8% (2/29), HHV-7: 79.3% (23/29); group 2: LSIL and HPV (-): HHV-6: 93.1% (27/29), HHV-7: 96.5% (28/29); LSIL and HPV (+): HHV-6: 0% (0/32), HHV-7: 90.6% (29/32); group 3: HSIL and HPV (-): HHV-6: 20% (2/10), HHV-7: 70% (7/10); HSIL HPV (+): HHV-6: 12% (3/25), HHV-7: 68% (17/25). HHV-6A DNA was not detected in any samples. CONCLUSIONS: (1) Both HHV-6 and HHV-7 infect the mucosal cells of the cervix with higher prevalence of HHV-7. (2) The higher prevalence of HHV-6 in LSIL HPV (-) samples compared with those with normal cytology indicates that it constitutes a possible risk factor for atypia production. (3) The presence of HHV-7 in all samples questions its role in the production of atypia. (4) The finding of HHV-6 and HHV-7 suggests that the cervical mucosa is a possible transmission pathway for these viruses.

Age-Related Patterns of DNA Detection and Specific IgG Subclasses in Healthy HHV-6- and HHV-7-Infected Individuals.

Human herpesvirus 6A (HHV-6A), Human herpesvirus 6B (HHV-6B), and Human herpesvirus 7 (HHV-7) can persist by establishing a lifelong infection which could have implications on the immunocompetent host. The aim of this work is to contribute with some knowledge about the HHV-6 A/B and HHV-7 infection in healthy individuals. We have carried out a longitudinal study in seropositive healthy individuals for the detection of viral DNA in saliva and plasma samples, and for determining a specific IgG isotype immune response, which enabled the performance of these viruses to be observed over time. Furthermore, an elderly population was transversely studied to provide data of the activity of these viruses in the older population. In the longitudinal study, HHV-6 DNA was occasionally detected and an isotype immune response with a specific IgG1 profile, while in the older group HHV-6 DNA was frequently detected and an isotype immune response with specific IgG1, IgG3, and IgG4. HHV-7 DNA was frequently detected in both groups and isotype patterns of specific IgG1, IgG3, and IgG4. The results of this study highlight that the long-lasting relationship in healthy HHV-6 A/B-infected individuals have the imprint of age groups.

Searching variables to assess recreational water quality: the presence of infectious human enterovirus and its correlation with the main variables of water pollution by multivariate statistical approach in Córdoba, Argentina.

Surface waters are used by local populations for different purposes, such as recreational activities, water source for human and animal consumption, and irrigation among others, which lead to the need for management strategies on water health and associated risks. During this study, we investigated physicochemical parameters, fecal coliform bacteria, and infectious human enterovirus detection to determine the water quality in different beaches (categorized as an urban area, non-urban areas, and an intermediate position) from San Roque Dam, in Argentina. Multivariate techniques were applied. Principal component analysis allowed identification of subgroup of variables responsible for the water quality. A cluster analysis and multivariate analysis of variance showed the urban beach as the highest pollution area. The following variables (measured at the urban beach) would be enough to describe the quality of the aquatic body: nitrites, fecal coliforms, total phosphorous, and infectious human enterovirus. The infectious human enterovirus was an independent variable detected in 69.1% of the samples showing a steady frequency of detection during the whole period studied and could identify human fecal contaminations as a source of water pollution. The selected variables would contribute to water quality regarding the risk for human health using San Roque dam waters for recreational propose.

Detección y respuesta inmune de virus herpes humano 6 (VHH-6) y virus herpes humano 7 (VHH-7) en población sana / Detection and immune response of human herpes virus 6 (HHV-6) and human herpesvirus 7 (HHV-7) in healthy population

El Herpesvirus Humano 6 (VHH-6) y el Herpesvirus humano 7 (VHH-7) pertenecen a la familia Herpesviridae con una amplia distribución en la población humana. La infección primaria ocurre a muy temprana edad, antes de los 2 años de vida, y el virus establece, en el hospedero susceptible, un modelo persistente de infección. La latencia del virus se produce en las células linfoides y en las glándulas salivales. La reactivación puede suceder en reiteradas ocasiones a lo largo de la vida de un infectado, ya sea éste inmunocompetente o inmunocomprometido, pudiendo el virus ser detectado en saliva y /o plasma. En individuos sanos, inmunocompetentes, la historia natural de la infección es poco conocida. El objetivo de este trabajo es contribuir a la comprensión de los modelos de persistencia viral de HHV-6 y de HHV-7 y de la respuesta inmune que la actividad viral desencadena en el hospedero sano, la cual se pone en evidencia por el perfil de isotipos específco de Inmunoglobulina G (IgG) específicos.

ABSTRACT: Human herpesvirus 6 (HHV-6) and Human herpesvirus 7 (HHV-7) belong to the Herpesviridae family and are widely distributed among the human population. The human primary infection occurs early, before the two years of age, and the virus establishes a persistent model of infection in the susceptible host. The virus remains latent mainly in lymph cells and salivary glands. Reactivation may occur several times throughout the life of infected individual, whether immune competent or immune compromised, with the virus being detected in saliva and/or plasma. In healthy immune competent individuals, the natural history of the infection is little known. The aim of this research was to contribute to the understanding of the models of viral persistence of HHV-6 and HHV-7 and the immune response that viral activity triggers in the healthy host, manifested by the profile of specific IgG isotypes (IgG1, IgG2, IgG3 and IgG4).

Detección y respuesta inmune de virus herpes humano 6 (VHH-6) y virus herpes humano 7 (VHH-7) en población sana / Detection and immune response of human herpes virus 6 (HHV-6) and human herpesvirus 7 (HHV-7) in healthy population

El Herpesvirus Humano 6 (VHH-6) y el Herpesvirus humano 7 (VHH-7) pertenecen a la familia Herpesviridae con una amplia distribución en la población humana. La infección primaria ocurre a muy temprana edad, antes de los 2 años de vida, y el virus establece, en el hospedero susceptible, un modelo persistente de infección. La latencia del virus se produce en las células linfoides y en las glándulas salivales. La reactivación puede suceder en reiteradas ocasiones a lo largo de la vida de un infectado, ya sea éste inmunocompetente o inmunocomprometido, pudiendo el virus ser detectado en saliva y /o plasma. En individuos sanos, inmunocompetentes, la historia natural de la infección es poco conocida. El objetivo de este trabajo es contribuir a la comprensión de los modelos de persistencia viral de HHV-6 y de HHV-7 y de la respuesta inmune que la actividad viral desencadena en el hospedero sano, la cual se pone en evidencia por el perfil de isotipos específco de Inmunoglobulina G (IgG) específicos.(AU)

ABSTRACT: Human herpesvirus 6 (HHV-6) and Human herpesvirus 7 (HHV-7) belong to the Herpesviridae family and are widely distributed among the human population. The human primary infection occurs early, before the two years of age, and the virus establishes a persistent model of infection in the susceptible host. The virus remains latent mainly in lymph cells and salivary glands. Reactivation may occur several times throughout the life of infected individual, whether immune competent or immune compromised, with the virus being detected in saliva and/or plasma. In healthy immune competent individuals, the natural history of the infection is little known. The aim of this research was to contribute to the understanding of the models of viral persistence of HHV-6 and HHV-7 and the immune response that viral activity triggers in the healthy host, manifested by the profile of specific IgG isotypes (IgG1, IgG2, IgG3 and IgG4).(AU)

IgG subclasses and DNA detection of HHV-6 and HHV-7 in healthy individuals.

Human herpesvirus 6 (HHV-6) and 7 (HHV-7) are common opportunistic agents in immunocompromised hosts, although infection with HHV-6 and HHV-7 can also be observed in immunocompetent hosts. Despite similar biology and epidemiology, this study evaluated differences in the IgG subclass distribution associated with HHV-6 and HHV-7 in seropositive, healthy persons. The identified subclasses were also compared with the detection of HHV-6 and HHV-7 DNA. For these assays, sera, plasma, and saliva samples were obtained from 40 healthy blood donors in Argentina who were seropositive for both HHV-6 and HHV-7. HHV-6 and HHV-7 DNA were detected in saliva and plasma samples using nested PCR, and specific IgG subclasses were determined using immunofluorescent assays of sera samples. HHV-7 DNA was detected in 90% of all plasma samples and in 100% of saliva samples. In contrast, HHV-6 DNA was not detected in any of the plasma samples, and it was detected in only 6 of 40 saliva samples. Determination of IgG subclass distributions showed that HHV-6 was restricted to IgG1, whereas HHV-7 IgG subclasses included two groups, one restricted only to IgG1 and the other to IgG1 and IgG3. These results demonstrate the differences between HHV-6 and HHV-7 DNA range detection in saliva and plasma samples, as well as the IgG subclass patterns for each virus type, in healthy persons in Argentina.

HHV-6 IgG4 isotype response following measles infection.

Human herpesvirus 6 (HHV-6) is widespread in the human population by infecting most individuals in early childhood. After primary infection, HHV-6 establishes a latent infection by remaining in circulating mononuclear cells of healthy individuals. The HHV-6 antibody titer increases after primary infection with measles virus. The present study was undertaken to determine the specific antiviral IgG1, IgG2, IgG3, and IgG4 subclass response patterns to HHV-6 in HHV-6-seropositive individuals with natural measles virus infection, measles vaccination, and rubella virus infection. The purpose of this study was to examine HHV-6-specific IgG isotype response in patients with acute virus coinfection. Serum samples were obtained from individuals who were seropositive for HHV-6 after natural primary infection with measles virus during an outbreak, measles vaccination, or rubella virus infection, and from healthy individuals. Sera were examined by indirect immunofluorescence assays for detection of HHV-6-specific IgG1, IgG2, IgG3, and IgG4 antibodies. A high percentage (69%) of those infected with measles virus had an HHV-6 IgG1 and IgG4 response (P < 0.001, chi(2) test), whereas persons vaccinated against measles, those infected with rubella, and healthy individuals showed an HHV-6 IgG1 response. These results demonstrate that natural measles virus infection induces an HHV-6 IgG isotype response, which suggests a shift in immune activity from a Th1 to a Th2 response. J. Med. Virol. 82:396-399, 2010. (c) 2010 Wiley-Liss, Inc.

Loss of maternally-derived human herpesvirus-7 immunity and natural infection in Argentinian infants.

BACKGROUND: Human herpes virus-7 (HHV-7) infection is widespread throughout the world. No data are available in Argentina about loss of maternally-derived HHV-7 immunity and natural infection. OBJECTIVES: The objective of this study was to characterize the time when children lose maternal antibodies and become susceptible to natural infection. METHODS: Sera from 39 pregnant women and 207 infants between 2 and 29 months of age were tested. Determination of IgG antibodies was made by indirect immunofluorescence. RESULTS: The seropositive ratio fell in the 2-4 month group (15% seropositive) and increased between 5 months (47% seropositive) and 23 months (67%). Geometric mean titers (GMT) of the infants aged 2-4 months (GMT = 60) were statistically different (p < 0.0001, Student's t-test) to those from the group of pregnant women (GMT = 83) and those from the other infant groups (p < 0.001, least significant difference (LSD) test). The GMT of the groups between 5 and 23 months did not show significant differences whereas those of infants between 24 and 29 months (GMT = 179, 79% seropositive) were different from all the groups studied (p < 0.0001, LSD test). CONCLUSIONS: This study shows a significant association between the loss of passive HHV-7 antibody and age. HHV-7 enters the susceptible population at 5 months, leading to the high prevalence of antibodies between 24 and 29 months of age. This study also shows that natural infection by HHV-7 in children during their first years of life follows the infection pattern found in developing countries.

Isotype immune response of IgG antibodies at the persistence and reactivation stages of human herpes virus 6 infection.

BACKGROUND: Infections with human herpes virus 6 (HHV-6) are very common. After primary infection, the virus remains latent and persists at low level in cells and tissues. Not usually associated with disease in the immunocompetent host, HHV-6 infection is a major cause of opportunistic viral infections in the immunosuppressed. The different stages of HHV-6 infection are difficult to characterize in the laboratory. OBJECTIVES: The aim of this paper was to assess the isotype patterns of IgG antibodies against HHV-6 in seropositive subjects during different stages of the virus activity. STUDY DESIGN: From a total of 190 human serum samples from 43 healthy children, 24 pregnant women and 24 patients with bone marrow transplants, 111 sera were processed by indirect immunofluorescence assay for the detection of IgG1, IgG2, IgG3 and IgG4 specific antibodies. The mean geometrical title (MGT) of the antibodies was calculated. RESULTS: All pregnant women had IgG1 (24/24; 100%; MGT 46). A 95% (41/43) of healthy infants had IgG1 (MGT 57). In bone marrow transplants, 58% (14/24) of the patients showed seroconversion (MGT 529) with an isotype response of IgG1 and IgG4 during the observation period. Remaining bone marrow transplant patients, who had the IgG without any variations (MGT 184), had isotype IgG1. CONCLUSIONS: These results revealed two different immune isotype response patterns. One of them is restrictive to IgG1 in the latent phase of HHV-6 infection in healthy children, pregnant women and transplant patients with stable levels of antibodies whereas IgG1 and IgG4 are detected in the reactivation of HHV-6 in transplant patients. The IgG isotype immune responses may contribute to the existing set of serological markers in characterizing the different stages of natural infection of HHV-6.