Human Herpesvirus 6 Positivity Research Articles

Challenges of Congenital HHV6 Infection Diagnosis and Treatment: Two Case Reports and Literature Review

Introduction: Congenital human herpesvirus 6 (HHV6) infection occurs in 1% of the general population and may result from the transmission of an inherited chromosomally integrated HHV6 (iciHHV6) or transplacental infection. It is mostly asymptomatic. Case reports: Case 1: a 29th-week-old female preterm newborn, admitted to the neonatal intensive care unit, became clinically unstable and irritable on the 20th day of hospitalization. Cranial ultrasound, revealed a significant posthemorrhagic tetraventricular dilation, with signs of ventriculitis. Investigations revealed HHV6 positivity on cerebrospinal fluid polymerase chain reaction multiplex panel testing and HHV6-DNA high viral loads in plasma samples. Case 2: a female late preterm newborn was admitted to the neonatal intensive care unit due to early-onset sepsis. Investigations revealed group B streptococcus positive blood cultures and cerebrospinal fluid HHV6 positivity on polymerase chain reaction multiplex panel testing, with negative bacterial culture. After 3 days of adequate antibiotic treatment, she maintained persistent moaning, which motivated a cranial ultrasound, revealing mild brain edema. Clinical improvement was observed only after beginning antiviral treatment in both newborns. Due to the persistency of high viral loads in both cases, despite antiviral treatment and clinical improvement, an iciHHV6 was suspected and posteriorly confirmed. Discussion/conclusion: Congenital iciHHV6 infection diagnosis is challenging because the presence of an iciHHV6 results in persistently high viral loads, even in the absence of active infection. Only a few diagnostic techniques can confirm active replication; unfortunately, these are not available in most countries. The decision to initiate antiviral treatment should be based on clinical judgment. Better ways for the diagnosis of active infection are needed.

Third cranial nerve palsy with confirmed HHV-6 positivity

We present a rare case of a 38-year-old man diagnosed with third cranial nerve paralysis, where no abnormalities were detected on MRI. Human Herpes Virus-6 (HHV-6) infection affecting the central nervous system and associated with cranial nerve paralysis is an unusual occurrence. This report underscores the importance of considering HHV-6 as a differential diagnosis in patients presenting with cranial nerve palsy and suggests the use of cerebrospinal fluid (CSF) HHV-6 polymerase chain reaction (PCR) testing for confirmation.

Association of HHV‑6 reactivation and SLC6A3 (C>T, rs40184), BDNF (C>T, rs6265), and JARID2 (G>A, rs9383046) single nucleotide polymorphisms in depression.

Major depressive disorder (MDD) is a global health concern with a complex etiology involving genetic, environmental and infectious factors. The exact cause of MDD remains unknown. The present study explored the association between genetic factors, human herpesvirus 6 (HHV-6) and MDD. The present study analyzed single nucleotide polymorphisms (SNPs) and HHV-6 viral load in oral buccal samples from patients with MDD (with and without blood relatives with MDD) and healthy controls. The study used high-resolution melt analysis to examine rs40184 (C>T) in the solute carrier family 6 member 3 (SLC6A31) gene, rs6265 (C>T) in the brain-derived neurotrophic factor (BDNF) gene and rs9383046 (G>A) in the jumonji and AT-rich interaction domain-containing 2 (JARID2) gene. HHV-6 infection and viral load was assessed using the quantitative PCR. Whole-exome sequencing was used to examine SNPs. The variant alleles of SNPs rs40184 [18/40 (45.00) vs. 29/238 (12.55%)] and rs6265 [30/54 (55.46) vs. 117/292 (40.06%)] were significantly more common in patients with MDD than in healthy controls, indicating they may be probable hereditary risk factors for MDD. HHV-6 positivity was significantly more common in carriers of the G/A genotype (12/15, 80%) than carriers of the G/G genotype (75/363, 20.7%) for rs9383046, implying that genetic variations may affect HHV-6 risk and MDD onset. Similarly, HHV-6 viral loads were significantly higher in carriers of the G/A genotype (99,990.85±118,392.64 copies/ng DNA) than carriers of the G/G genotype (48,249.30±101,216.28 copies/ng DNA) for rs9383046. Whole-exome sequencing identified two SNPs in JARID2 (rs11757092 and rs9383050) associated with MDD, highlighting its genetic complexity. The present study helps explain the complex interactions between HHV-6 infection, genetics and MDD onset, improving understanding of how SNPs in JARID2 contribute to HHV-6 infection and MDD onset; these findings may impact future approaches to diagnosing and treating MDD.

Human Herpesvirus 6-A Rare Aetiologic Agent for CNS Infections in Immunocompetent Individuals or an Underestimation?

Background: Human herpesvirus 6 (HHV-6) is considered a ubiquitous virus, with many countries reporting a seroprevalence of more than 80-90% among the general population. However, this virus is unique among herpesviruses in its ability to integrate into the genetic material of the host's cells. Thus, there are three ways by which HHV-6 can cause an active infection-primary infection, reactivation of a latent acquired infection, or activation of iciHHV-6 (inherited chromosomally integrated HHV-6). Whole blood quantitative polymerase chain reaction (qPCR) is very useful in distinguishing between iciHHV-6 and primary infection/reactivation. Our aim is to assess the role of HHV-6 in the aetiology of central nervous system (CNS) infections in adults and children, to describe all HHV-6-positive cases in an attempt to determine the susceptible population and to identify potential risk factors that can be linked to HHV-6 meningoencephalitis. Methods: We performed a retrospective study involving patients that were admitted to Prof. Dr. Matei Bals National Institute of Infectious Diseases, Bucharest, Romania, with a diagnosis of meningitis or encephalitis. We only selected the clinical records of patients that had a multiplex PCR Biofire® FilmArray® meningitis/encephalitis panel. Results: We report a 5% HHV-6 positivity in the cerebrospinal fluid (CSF) of patients with CNS infections tested with a commercial multiplex PCR M/E (meningitis/encephalitis) panel. Additionally, 2% to 4% of the total study population (n = 100) had active HHV-6 infections, which denotes 40 to 80% of the HHV-6-positive samples. We did not observe any statistically significant correlation between HHV-6 positivity in the CSF and variables such as age, sex, or comorbidities, including obesity, diabetes, hypertension, immunosuppression, or oncologic disease. Therefore, no risk factors could be linked with HHV-6 positivity in the CSF. Conclusions: although multiplex qualitative PCR is highly useful for providing rapid results and identifying nearly every pathogen that can cause meningitis/encephalitis, we have to be aware of this type of test's limitations. All patients with HHV-6 detectable in their CSF via a multiplex PCR test should also undergo qPCR testing from both CSF and blood to prevent over-diagnosing HHV-6 CNS infections, to avoid unnecessary antiviral treatments, and ensure the accurate identification of the true diagnosis.

Chronic Alcoholism and HHV-6 Infection Synergistically Promote Neuroinflammatory Microglial Phenotypes in the Substantia Nigra of the Adult Human Brain.

Both chronic alcoholism and human herpesvirus-6 (HHV-6) infection have been identified as promoters of neuroinflammation and known to cause movement-related disorders. Substantia Nigra (SN), the dopaminergic neuron-rich region of the basal ganglia, is involved in regulating motor function and the reward system. Hence, we hypothesize the presence of possible synergism between alcoholism and HHV-6 infection in the SN region and report a comprehensive quantification and characterization of microglial functions and morphology in postmortem brain tissue from 44 healthy, age-matched alcoholics and chronic alcoholics. A decrease in the perivascular CD68+ microglia in alcoholics was noted in both the gray and white matter. Additionally, the CD68+/Iba1− microglial subpopulation was found to be the dominant type in the controls. Conversely, in alcoholics, dystrophic changes in microglia were seen with a significant increase in Iba1 expression and perivascular to diffuse migration. An increase in CD11b expression was noted in alcoholics, with the Iba1+/CD11b− subtype promoting inflammation. All the controls were found to be negative for HHV-6 whilst the alcoholics demonstrated HHV-6 positivity in both gray and white matter. Amongst HHV-6 positive alcoholics, all the above-mentioned changes were found to be heightened when compared with HHV-6 negative alcoholics, thereby highlighting the compounding relationship between alcoholism and HHV-6 infection that promotes microglia-mediated neuroinflammation.

Pathogen or Bystander: Clinical Significance of Detecting Human Herpesvirus 6 in Pediatric Cerebrospinal Fluid.

Human herpesvirus 6 (HHV-6) is an important cause of meningitis and meningoencephalitis. As testing for HHV-6 in cerebrospinal fluid (CSF) is more readily available using the FilmArray Meningitis/Encephalitis panel (FA-ME; BioFire Diagnostics, Salt Lake City, UT), we aimed to determine the clinical significance of detecting HHV-6 in order to identify true infections and to ensure appropriate antiviral initiation. Chart review on 25 patients positive for HHV-6 by FA-ME was performed to determine clinical presentation, comorbidity, treatment, and outcome. The presence of chromosomally integrated HHV-6 (ciHHV-6) DNA was also investigated. Of 1,005 children tested by FA-ME, HHV-6 was detected in 25 (2.5%). Five patients were diagnosed with either HHV-6 meningitis or meningoencephalitis based on HHV-6 detection in CSF, clinical presentation, and radiographic findings. Detection of HHV-6 by FA-ME led to discontinuation of acyclovir within 12.0 h in all 12 patients empirically treated with acyclovir. Six of the 12 patients were started on ganciclovir therapy within 6.8 h; 4 of these were treated specifically for HHV-6 infection, whereas therapy was discontinued in the remaining 2 patients. CSF parameters were not generally predictive of HHV-6 positivity. The presence of ciHHV-6 was confirmed in 3 of 18 patients who could be tested. Five of the 25 patients included in the study were diagnosed with HHV-6 meningitis/meningoencephalitis. FA-ME results led to discontinuation of empirical antiviral treatment in 12 patients and appropriate initiation of ganciclovir in 4 patients. In our institution, detection of HHV-6 using FA-ME led to faster establishment of disease etiology and optimization of antimicrobial therapy.

Clinical Significance of Cerebrospinal Fluid Herpesvirus 6 Positivity- A Case Series Study

Human herpesvirus 6 (HHV-6) is a common pathogen at childhood, remains in a latent form and can reactivate, causing encephalitis with the impairment of the immune system. The acute primary HHV-6 infection in adult immunocompetent hosts is being questioned. The cerebrospinal fluid (CSF) HHV-6 positivity can be detected in infection, in latency period, in asymptomatic reactivation or in viral chromosomic integration. To establish the clinical significance of CSF HHV-6 positivity, the authors reviewed the CSF HHV-6 positive cases in a tertiary hospital from 13 years. A total of 2111 tests were made with 0.9% of HHV-6 positivity. Only 2 cases were considered “likely” HHV-6 infected, reinforcing that most positive results do not indicate infection. Immune status and quantitative viral load studies on CSF and blood can be of great benefit, but clinical judgement is fundamental to determine the significance of HHV-6 positivity and need for treatment.

The Activation of Cytomegalovirus and Human Herpes Virus 6 After Liver Transplantation

Background: Cytomegalovirus (CMV) and Human Herpes Virus-6 (HHV-6) activation after liver transplantation have been associated with increased graft rejection and adverse outcomes. This study aimed at investigating the development and timing of CMV infection after liver transplantation and its relation to post-transplantation HHV-6 activation. Methods: Patients undergoing liver transplantation were enrolled, regardless of their age, place of residence, or their liver failure etiology. Blood samples were collected at baseline and every week for a period of 12 weeks and were tested for anti-CMV IgG and anti-HHV-6 IgG, CMV pp65 antigenemia, as well as CMV and HHV-6 DNA using the Polymerase Chain Reaction (PCR) method. Results: Among 46 liver transplant recipients, 17 (36.9%) developed CMV infection within 3 months after transplantation. Before transplantation, 42 (91.3%) and 41 (89.1%) recipients were seropositive for CMV and HHV-6, respectively. Fifty percent of patients were positive for CMV antigenemia, among which 73.9% became symptomatic for CMV infection. Half of the patients had positive test results for CMV PCR with a significant relationship between the CMV viral load and the development of symptomatic CMV infection (P = 0.001). Twenty-five (54.3%) patients had positive test results for HHV-6 PCR with a significant relationship between HHV-6 positivity and the development of clinical presentation (P = 0.002). The average post-transplantation time to HHV-6 and CMV activation was 19.4 ± 86.5 and 28.4 ± 60.5 days, respectively, with a linear relationship in the regression analysis. Conclusions: The HHV-6 infection, either as primary infection or reactivation, leads to an increased risk of CMV infection and symptomatic disease after liver transplantation. Activation of HHV-6 precedes the CMV activation in time.

HHV6 Specific T-Cells Are Predictive Biomarker of Active HHV6 Infection after Allogeneic Hematopoietic Stem Cell Transplantation: Results of a Prospective Study in 213 Patients

BACKGROUND: Although Human herpesvirus 6 (HHV6) reactivation in healthy individuals usually occurs without significant morbidity, in recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is associated with severe clinical manifestations and increased transplant-related mortality (TRM). The role of HHV6 in transplant-related complications remains in question, considering that both latent and active viral infection can occur. Moreover, only limited experiences are reported on HHV6-specific immune responses after HSCT, and their correlation with clinical outcome is largely unexplored.METHODS: From February 2013 to October 2015, we conducted a prospective observational study to investigate HHV6 reactivation in 213 consecutive adult patients (median age 52 years) who received allo-HSCT for high-risk hematological malignancies (57% acute leukemia) in our institute. Stem cell donors were family haploidentical (104), HLA identical sibling (39), unrelated (63), cord blood (7). Stem cell source was mainly T-cell replete PBSCs (87%). Viral load was weekly monitored by quantitative PCR in plasma within the first month after HSCT. Numbers of IFNγ-producing HHV6-T-cells were determined by enzyme-linked immunospot assay (ELISPOT). We challenged patients PBMC against a library of overlapping peptides covering the entire sequence of the immunodominant virus protein U54, expressed during the lytic cycle of virus replication. Patients were evaluated at a median of 34 days after HSCT (HHV6-; 57 patients) for controls or by the 4th day after the first HHV6 DNAemia (median 32 days) for reactivating patients (HHV-6+; 54 patients).RESULTS: HHV6-reactivation occurred in 56% of patients at 100 days, with a median time of 28 days after HSCT. HHV6 was detected in plasma for 86% of patients, while 33% resulted positive in other materials: 9 BM aspirates, 39 gut biopsies, 3 BAL, 5 CSF. All patients received acyclovir as prophylaxis. Only 41% of reactivating patients presented a clinically relevant HHV6 infection (HHV6 positivity in presence of HHV6-related clinical symptoms and/or HHV6-disease). Clinical manifestations were: fever (25), skin rash (37), hepatitis (19), diarrhoea (28), encephalitis (5), BM suppression (30). According to center guidelines, antiviral treatment was given in 23% of reactivating patients, for uncontrolled clinically relevant HHV6 infection.Overall survival (OS) was not different in HHV6 reactivating patients compared to controls (p=0,2). Relapse incidence and TRM were not affected by HHV6. All HSCT recipients showed a better OS with CD3+ cells≥200/mcl at 30 days (p <0.001), independently of HHV6. In univariate analysis, we identified the following risk factors for HHV6-reactivation: active disease status before HSCT (p=0,052), haploidentical HSCT (p=0,003), PT-Cy use (p <0.001), CMV reactivation (p=0,001), GvHD (p=0,003), CD3+ cells<200/mcl at 30 days (p=0,013).The number of IFNγ-producing HHV6-specific T-cells was significantly higher in HHV6 reactivating patients (p= 0.0149; mean number of specific T-cells 43.48 per 10^5 PBMC) than in non-reactivating patients (specific T-cells 12.57 per 10^5 PBMC), especially in the presence of active and clinically relevant HHV6 infection (p<0,0001; mean number of specific T-cells 81.46 per 10^5 PBMC). No influence of IFNγ-producing CMV specific T-cells, absolute counts of CD3+ T cells or GvHD was observed.CONCLUSIONS: In this study, we observed that active disease status before HSCT, haploidentical donors, especially using PT-Cy, CMV reactivation, GvHD and lower CD3+ counts at 30 days, are strong predictors of HHV6 reactivation. HHV6-specific T-cells, detectable by ELISPOT assay despite extremely low T-cell numbers and immunosuppressive therapy, are significantly associated with active and clinically relevant HHV6 infections, representing a new and promising tool to unravel the role of HHV6 positivity in allo-HSCT recipients. DisclosuresCiceri:MolMed SpA: Consultancy. Bonini:TxCell: Membership on an entity's Board of Directors or advisory committees; Molmed SpA: Consultancy.

Detection frequency of human herpesviruses-6A, -6B, and -7 genomic sequences in central nervous system DNA samples from post-mortem individuals with unspecified encephalopathy.

In this autopsy-based study, human herpesvirus-6 (HHV-6) and -7 (HHV-7) genomic sequence frequency, HHV-6 variants, HHV-6 load and the expression of HHV-6 antigens in brain samples from the individuals, with and without unspecified encephalopathy (controls), using nested and real-time polymerase chain reactions, restriction endonuclease, and immunohistochemical analysis were examined. GraphPad Prism 6.0 Mann-Whitney nonparametric and chi-square test and Fisher's exact test were used for statistical analysis. The encephalopathy diagnoses were shown by magnetic resonance imaging made during their lifetime and macro- and microscopically studied autopsy tissue materials. Widespread HHV-6 and/or HHV-7 positivity was detected in the brain tissue of various individuals with encephalopathy, as well as in controls (51/57, 89.4% and 35/51, 68.6%, respectively; p = 0.009). Significantly higher detection frequency of single HHV-6 and concurrent HHV-6 + HHV-7 DNA was found in pia mater meninges, frontal lobe, temporal lobe, and olfactory tract DNAs in individuals with encephalopathy compared to the control group. HHV-6 load and higher frequency of the viral load >10 copies/10(6) cells significantly differed in samples from individuals with and without encephalopathy. The expression of HHV-6 antigens was revealed in different neural cell types with strong predominance in the encephalopathy group. In all HHV-6-positive autopsy samples of individuals with and without encephalopathy, HHV-6B was revealed. Significantly higher detection frequency of beta-herpesvirus DNA, more often detected HHV-6 load >10 copies/10(6) cells, as well as the expression of HHV-6 antigens in different brain tissue samples from individuals with encephalopathy in comparison with control group indicate on potential involvement of these viruses in encephalopathy development.

Herpes viruses and human papilloma virus in nasal polyposis and controls

IntroductionChronic rhinosinusitis with nasal polyps is a multifactorial disease entity with an unclear pathogenesis. Contradictory data exist in the literature on the potential implication of viral elements in adult patients with chronic rhinosinusitis. ObjectiveTo compare the prevalence of human herpes viruses (1–6) and Human Papilloma Virus in adult patients with chronic rhinosinusitis with nasal polyps and healthy controls. MethodsViral DNA presence was evaluated by real-time polymerase chain reaction application to nasal polyps specimens from 91 chronic rhinosinusitis with nasal polyps patients and nasal turbinate mucosa from 38 healthy controls. ResultsEpstein–Barr virus positivity was higher in nasal polyps (24/91; 26.4%) versus controls (4/38; 10.5%), but the difference did not reach significance (p=0.06). Human herpes virus-6 positivity was lower in nasal polyps (13/91; 14.29%) versus controls (10/38; 26.32%, p=0.13). In chronic rhinosinusitis with nasal polyps group, 1 sample was herpes simplex virus-1-positive (1/91; 1.1%), and another was cytomegalovirus-positive (1/91; 1.1%), versus none in controls. No sample was positive for herpes simplex virus-2, varicella-zoster virus, high-risk-human papilloma viruses (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59) and low-risk-human papilloma viruses (6, 11). ConclusionDifferences in Epstein–Barr virus and human herpes virus-6 positivity among patients with chronic rhinosinusitis with nasal polyps and healthy controls are not statistically significant, weakening the likelihood of their implication in chronic rhinosinusitis with nasal polyps pathogenesis.

Human herpesvirus 6 involvement in paediatric drug hypersensitivity syndrome.

Human herpesvirus (HHV)6 positivity in the context of drug hypersensitivity syndrome (DHS) may influence disease severity. Systemic corticosteroid treatment of those with DHS testing positive for HHV6 has been speculated to prolong the duration of disease. To evaluate whether paediatric HHV6-positive patients with DHS develop a more severe illness than those without presumed reactivation, and to evaluate the response to systemic corticosteroid treatment. A retrospective case series of 29 paediatric inpatients treated for DHS and tested for HHV6 was undertaken. HHV6-positive and -negative patients were identified and stratified into groups treated or not treated with systemic corticosteroids to examine their disease severity on the basis of hospital length of stay (LOS), total number of febrile days (Tfeb) and days until cessation of progression (CTP). Human herpesvirus6-positive patients had similar demographic characteristics to those of HHV6-negative patients, but had significantly longer hospital LOS (11·5 days vs. 5 days, P = 0·039), Tfeb (12·5 days vs. 3 days, P = 0·032) and CTP (4 days vs. 2 days, P = 0·014). All HHV6-positive patients and most (80%) of the HHV6-negative patients received systemic corticosteroids. Among the HHV6-negative patients, those who received corticosteroids showed significantly shorter CTP than those who did not (3 days vs. 2 days, P = 0·043). Additionally, there was a trend towards shorter hospital LOS and Tfeb among HHV6-negative patients who received corticosteroids vs. those who did not, although these differences were not statistically significant. The most common inciting drugs included trimethoprim-sulfamethoxazole (34%), phenytoin (10%) and amoxicillin (10%). Human herpesvirus6 positivity with DHS is associated with a more severe disease course. Treatment with systemic corticosteroids was associated with a trend towards reduced hospital LOS and Tfeb, and a significantly reduced number of days until cessation of progression.

Human Herpes Virus-6 and Clinical Manifestations After Allogeneic Hematopoietic Stem Cell Transplantation

Abstract 1960 BACKGROUND:Human herpesvirus 6 (HHV-6) is increasingly recognized as an opportunistic and potentially life-threatening pathogen in recipients of allogeneic Hematopoietic Stem Cell Transplantation (HSCT). Reported clinical manifestations of HHV-6 infection in transplanted patients are skin rash, interstitial pneumonia, bone marrow suppression and encephalitis. Moreover, an increasing number of clinical reports suggest that HHV-6 can facilitate the occurrence of other severe clinical complications of allogeneic HSCT, including Graft-versus-Host Disease (GvHD), ultimately increasining transplant-related mortality. Still, the actual incidence of HHV-6 infection in recipients of HSCT and the causative link between infection and clinical complications remain elusive, mostly due to the small and heterogeneous patient cohorts analyzed to date. METHODS:From January 2009 to July 2011, we retrospectively evaluated 43 consecutive adult patients (median age 51 years) who developed positivity to HHV-6 after allogeneic HSCT for high-risk hematological malignancies. Stem cell donor was for 30 patients family haploidentical, for 5 an HLA identical sibling, and for 8 an unrelated volunteer (1 of which cord blood). The viral load was determined by quantitative PCR in cell-free body fluids such as plasma, bronchoalveolar lavage, cerebrospinal fluid, bone marrow aspirates or in gastrointestinal biopsies. At the time of positivity all patients were receiving acyclovir as viral prophylaxis except 5. Sixteen patients had clinical acute GvHD at time of HHV-6 positivity (grade III-IV in 14), and 33 were profoundly immunosuppressed with variable association of 2–4 immunosuppressive drugs (steroids included). Moreover concomitant CMV positivity was detected in 11 patients, while a severe neutropenia in 12. RESULTS:Median time from allogeneic HSCT to HHV-6 reactivation was 36 days (range: 7–625). In 19 patients HHV-6 was detected in plasma, with a median viral load of 19,454 cp/mL (34-4,524,600); 15 had concomitant fever, 5 skin rash of new onset, 4 impaired liver function, and 5 developed cytopenia subsequently to the infection. In 7 patients HHV-6 was detected in the bone marrow: the median viral load was 163’800 cp/mL (568-1’552’982). In 8 patients, all febrile, HHV-6 was observed in bronchoalveolar lavage samples with a median of 4’149 cp/mL (85–39250). In 16 patients, 10 with documented gut aGvHD, 11 with diarrhoea, HHV-6 was detected in gastrointestinal biopsies with a median of 7’510 cp/mL (120-4’524’600). HHV-6 was found in cerebrospinal fluid in 4 cases (all within 30 days after HSCT); the median viral load was 29’352 cp/mL (4’508-1’552’982); all these patients experienced encephalitis with confusion and anxiety, 2 suffered seizures and 3 showed abnormal findings on brain MRI. Amongst patients with organ localizations of HHV-6 only 28% had concomitant plasma positivity. HHV-6 positivity led to antiviral pharmacological treatment only when associated with clinical manifestations (n=21), using as first choice therapy foscarnet. Amongst the total 43 patients with documented HHV-6 positivity 11 completely solved the clinical event, whereas 19 (44%) died. CONCLUSIONS:HHV-6 infection/reactivation is associated with high morbidity and mortality in patients who undergo allogeneic HSCT. HHV-6 infection typically occurred close to the time of neutrophil engraftment. HSCT from an HLA-mismatched donor and steroid administration were associated with increased risk of active HHV-6 infection. Development of encephalitis was associated with high HHV-6 viral load. The regular monitoring of HHV-6 DNA in allogeneic HSCT recipients, using a real-time PCR assay, may be useful for identifying active HHV-6 infection and for the introduction of a pre-emptive treatment, possibly reducing the incidence of the most severe clinical complications. Disclosures:No relevant conflicts of interest to declare.

Human Herpesvirus 6 Infection after Hematopoietic Cell Transplantation: Is Routine Surveillance Necessary?

Human herpesvirus 6 (HHV6) may be an important pathogen following allogeneic hematopoietic cell transplantation (HCT). We prospectively evaluated weekly HHV6 viremia testing after allogeneic HCT using a quantitative polymerase chain reaction (PCR)-based assay. HHV-6 viremia was detected in 46 of 82 (56%) patients at a median of 23 days post-HCT (range: day +10 to +168). More males (65% vs females 39%, P = .03) and recipients of umbilical cord blood (UCB 69% vs unrelated donor [URD], 46% vs sibling donor [20%] grafts, P = 0.01) reactivated HHV-6. Patients with HHV6 viremia had more cytomegalovirus (CMV) reactivation (26% vs 5.5%, P = .01) and unexplained fever and rash (23.9% vs 2.7%, P = .01) compared with patients without HHV6 viremia. High-level HHV6 (≥ 25,000 copies/mL) versus lower levels were associated with more culture-negative pneumonitis (72.7% vs 22.8%, P = .01). Twenty HHV6-positive patients were treated with foscarnet, ganciclovir, or cidofovir for HHV6 or other coexistent viruses. Within 2 weeks, HHV6 viremia resolved more commonly in treated (65%) than untreated patients (31%), P = .02. Survival at 3 months was similar in treated and untreated patients (90% vs 81%, P = .4). Survival at 3 and 6 months post-HCT were not affected by HHV6 positivity (3 months HHV6+ 85% vs 78%, P = .46; 6 months HHV6+ 70% vs 72%, P = .89) or by HHV6 level (3-month high level 73% vs 89%, P = .23; 6-month high level 64% vs 71%, P = .54). Neither the occurrence of HHV6, degree of viremia, nor use of antiviral drugs influenced short-term survival after HCT.

The role of human herpesvirus 6, human herpesvirus 7, Epstein-Barr virus and cytomegalovirus in the aetiology of pityriasis rosea

To identify the role of human herpesvirus 6 (HHV-6), HHV-7, Epstein-Barr virus (EBV) and cytomegalovirus (CMV) in the pathogenesis of pityriasis rosea (PR). Polymerase chain reaction with specific primers for HHV-6 and HHV-7 DNA sequences was performed on the blood and tissue samples of 25 patients with PR and on the blood samples of age- and sex-matched healthy controls. HHV-6, EBV, CMV immunoglobulin M (IgM) and IgG were analysed by enzyme-linked immunosorbent assay, HHV-7 IgM and IgG were analysed by indirect immunofluorescence on the serum samples of the study population. In the patient group, the values were studied 2 weeks later again (second control). There were no differences between the first and second controls of the patients and healthy subjects regarding HHV-6 IgM, HHV-7 IgM, CMV IgM, EBV IgM results. There were significant differences between the first [HHV-6 DNA (2 of 25), HHV-7 DNA (6 of 25)] and second control [HHV-6 DNA (1 of 25), HHV-7 DNA (11 of 25)] of the patients for the blood samples in favour of HHV-7. PR patients showed higher amounts of HHV-6 and HHV-7 DNA positivity when compared with that of healthy subjects. HHV-7 seemed to be more important regarding tissue samples [HHV-6 DNA (7 of 25), HHV-7 DNA (12 of 25) first control, HHV-6 DNA (6 of 25), HHV-7 DNA (12 of 25) second control] as well as blood samples. Though our results failed to support a causal relationship among EBV, CMV and PR, they indicated a possible role for HHV-6 and especially HHV-7 in a group of Turkish patients but other aetiological factors may exist.

The prevalence of human herpesvirus 6 in human sensory ganglia and its co-occurrence with alpha-herpesviruses

Human herpesvirus 6 (HHV-6) persists in the central nervous system, but its prevalence in the peripheral nervous system, a preferred latency site for herpesviruses, has not been studied. Using nested polymerase chain reaction (PCR), the authors determined the distribution of HHV-6 in human sensory ganglia. HHV-6 was present in 30% of trigeminal, 40% of geniculate, 25% of vestibular, and 55% of dorsal root ganglia. It co-occurred with alpha-herpesviruses (herpes simplex virus type 1 or varicella-zoster virus) in 91% of the ganglia. As HHV-6 positivity did not depend on the presence of inflammatory cells, known to harbor the virus, HHV-6 probably resides in the ganglia themselves.

Proportion positive for Epstein-Barr virus, cytomegalovirus, human herpesvirus 6, Toxoplasma, and human immunodeficiency virus types 1 and 2 in heterophile-negative patients with an absolute lymphocytosis or an instrument-generated atypical lymphocyte flag.

To determine the proportion of patients with evidence of an acute infection due to Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), Toxoplasma, or human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2) in heterophile-negative patients with an absolute lymphocytosis or an instrument-generated atypical lymphocyte flag, and to develop a cost-effective testing algorithm for managing such heterophile-negative patients. We conducted a prospective investigation of 70 selected outpatients who tested negative for heterophile antibody in association with an absolute lymphocytosis or instrument-generated atypical lymphocyte flag. The control population consisted of 50 patients who were heterophile negative and had a normal absolute lymphocyte count and no instrument-generated atypical lymphocyte flag. A large outpatient laboratory system. Viral serology for HHV-6 was performed by immunofluorescence, and all other serologies were performed by enzyme-linked immunoassay. All testing was for immunoglobulin (Ig) M antibodies, except in the case of HIV. The proportion of study patients positive for EBV was 40% (28/70); for CMV, 39% (27/70); for HHV-6, 25% (16/65); for Toxoplasma, 3% (2/70); and for HIV, 0% (0/70). All 50 control patients were negative for EBV IgM antibodies. When patients with more than 1 positive viral test were excluded from analysis, positivity was 20% (9/45) for EBV, 22% (10/45) for CMV, 9% (4/45) for HHV-6, and 2% (1/45) for Toxoplasma. Utilizing hypothesis-generating logistic regression models, Downey type II atypical lymphocytes were significantly associated with EBV positivity (P =.006), while Downey type III lymphocytes were significantly associated with HHV-6 positivity (P =.016), and there was a trend for the association of Downey type I lymphocytes with CMV positivity (P =.097). A positive viral serology was identified in 70% of study patients. Multiple positive serologies complicate establishing a definitive diagnosis. Potential cost savings may be associated with the use of an appropriate testing algorithm.

Human herpesvirus 6 is an important pathogen in infectious lung disease after allogeneic bone marrow transplantation.

Two hundred and ten bronchoalveolar lavage (BAL) samples were obtained from 50 patients 10 days before and on defined days after allogeneic bone marrow transplantation (BMT). The samples were examined for human cytomegalovirus (HCMV) and human herpesvirus-6 (HHV-6) by polymerase chain reaction (PCR). Fifteen patients (30%) had a positive result for HCMV in at least one sample and 25 (50%) were positive for HHV-6 in at least one sample. Five patients developed HCMV-associated interstitial pneumonia (HCMV-IP) within 100 days after allogeneic BMT. Four of these patients were positive for both HCMV and HHV-6. Conspicuous HHV-6 positivity was detected in BAL samples obtained because of respiratory symptoms. No association was found between detection of HHV-6 and acute graft-versus-host disease. Engraftment failure or a delay in engraftment was observed in none of the 50 patients. The data from this study indicate that HHV-6 is a pathogen in HCMV-associated, as well as in non-HCMV-associated infectious lung disease after BMT.

Abortion in human herpesvirus 6 DNA-positive pregnant women.

Abortion in human herpesvirus 6 DNA-positive pregnant women.