Impact of human metapneumovirus and human cytomegalovirus versus other respiratory viruses on the lower respiratory tract infections of lung transplant recipients

Viral respiratory tract infections in lung transplant recipients may be severe. During three consecutive winter-spring seasons, 49 symptomatic lung transplant recipients with suspected respiratory viral infection, and 26 asymptomatic patients were investigated for presence of respiratory viruses either in 56 nasopharyngeal aspirate or 72 bronchoalveolar lavage samples taken at different times after transplantation. On the whole, 1 asymptomatic (3.4%) and 28 symptomatic (57.1%) patients were positive for human metapneumovirus (hMPV, 4 patients), influenza virus A (3 patients), and B (2 patients), respiratory syncytial virus (2 patients), human coronavirus (2 patients), human parainfluenza virus (2 patients), rhinovirus (5 patients), while 4 patients were coinfected by 2 respiratory viruses, and 5 were infected sequentially by 2 or more respiratory viruses. In bronchoalveolar lavage samples, hMPV predominated by far over the other viruses, being responsible for 60% of positive specimens, whereas other viruses were present in nasopharyngeal aspirates at a comparable rate. RT-PCR (detecting 43 positive samples/128 examined) was largely superior to monoclonal antibodies (detecting 17 positive samples only). In addition, HCMV was detected in association with a respiratory virus in 4/18 HCMV-positive patients, and was found at a high concentration (>10(5) DNA copies/ml) in 3/16 (18.7%) patients with HCMV-positive bronchoalveolar lavage samples and pneumonia. Coinfections and sequential infections by HCMV and respiratory viruses were significantly more frequent in patients with acute rejection and steroid treatment. In conclusion: (i) about 50% of respiratory tract infections of lung transplant recipients were associated with one or more respiratory viruses; (ii) hMPV largely predominates in bronchoalveolar lavage of symptomatic lung transplant recipients, thus suggesting a causative role in lower respiratory tract infections; (iii) RT-PCR appears to be the method of choice for detection of respiratory viruses in lung transplant recipients, (iv) a high HCMV load in bronchoalveolar lavage is a risk factor for viral pneumonia, suggesting some measure of intervention for the control of viral infection.     

Unsuitability of exhaled breath condensate for the detection of herpesviruses DNA in the respiratory tract

Exhaled breath condensate is a non-invasive method for detecting a wide number of molecules as well as genomic DNA in the airways. No study investigated the detection of viral DNA in exhaled breath condensate, while only one study excluded its usefulness for detection of influenza virus RNA. In this study, the suitability of exhaled breath condensate for detecting herpesviruses infection or reactivation in the respiratory tract of lung transplant recipients was evaluated.Twenty-four matched samples (exhaled breath condensate, bronchoalveolar lavage, whole blood, transbronchial biopsy) were evaluated for the detection of human cytomegalovirus (HCMV), human herpesvirus (HHV-6 and -7), Epstein-Barr virus (EBV) DNA by real-time PCR.Eighteen bronchoalveolar lavages (75%), six whole blood samples (25%), and two transbronchial biopsies (8.3%) were positive for at least one herpesvirus. Only one exhaled breath condensate specimen was positive for HCMV DNA (and positive also in the bronchoalveolar lavage, with low viral load in both specimens); while no other patient, irrespective of the viral load in any specimen or the presence of clinical symptoms and signs, had a positive exhaled breath condensate.These findings seem to exclude the suitability of exhaled breath condensate for non-invasive detection of viral DNA in the respiratory tract of lung transplant recipients.     

Direct detection of human cytomegalovirus in urine specimens from renal transplant patients following polymerase chain reaction amplification

A polymerase chain reaction (PCR) assay was used to amplify human cytomegalovirus (HCMV) directly from urine specimens taken from renal transplant patients. In serial urine samples from patients who had at least one specimen positive for HCMV; the PCR assay consistently detected the presence of HCMV DNA sequences, whereas virus detection by other tests such as enzyme-linked immunosorbent assay (ELISA), nonradioactive DNA hybridization assay, and virus isolation were variable. Of 37 specimens positive by PCR, 36 were positive by either ELISA, hybridization assay, or virus isolation. Infectious virus was detected in 13 of the 37 PCR-positive urines. HCMV DNA was detected by PCR in all samples that were positive for HCMV by either hybridization assay or virus isolation. The viral genome copy number was determined by PCR assay for several urine samples that were positive by virus isolation but negative for HCMV by ELISA or hybridization assay. Viral genome copy number estimates indicated the presence of HCMV at very low levels in these urines verifying the fidelity of the virus isolation procedures. The consistency of the PCR assay makes it an ideal method for detection of infection and monitoring antiviral drug therapy in patients infected with HCMV.     

Human herpesvirus-6 and human herpesvirus-7 infections in bone marrow transplant recipients

Human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), and human herpesvirus-7 (HHV-7) DNA in peripheral blood leukocytes (PBL) of 61 bone marrow transplant recipients was monitored weekly during the first 12 weeks post-transplantation by a nested polymerase chain reaction (PCR). Thirty-seven (61%), 17 (28%), and 32 (53%) of patients had one or more PBL specimens positive for HCMV, HHV-6 or HHV-7 DNA, respectively. HHV-7 DNA in PBL during the early post-transplant period was associated with a longer time to neutrophil engraftment (mean 28.8 days vs 19.8 days; P = 0.01). In two patients who failed to engraft, HHV-6 DNA and HHV-7 DNA was detected in plasma and PBL, respectively, early in their post-transplant period. Patients with HCMV disease were more likely to have concurrent HHV-7 DNA in PBL prior to onset of disease than were patients with asymptomatic HCMV infection, suggesting that HHV-7 may be a cofactor in the progression from HCMV infection to HCMV disease. In the 17 patients (179 specimens) in whom viral DNA in plasma was studied (in addition to PBL), a positive result was found only in 3. In each, viral DNA in plasma appeared to correlate with clinically significant disease. HHV-7 DNA in plasma was associated with encephalitis in an allograft recipient. J. Med. Virol. 53:295–305, 1997. © 1997 John Wiley & Sons, Inc.     

Cytomegalovirus DNA detection in sera from patients with active cytomegalovirus infections.

Using a specific and sensitive polymerase chain reaction method, we detected reliably the presence of human cytomegalovirus (HCMV) DNA directly in serum samples collected at an early stage of HCMV infection, even before immunoglobulin M (IgM) antibodies were measurable. HCMV DNA was detected in serum from all patients with active HCMV infection; in 91% of these patients, HCMV DNA was found in the acute-phase serum. In 13 of 44 patients, HCMV DNA was found in serum before HCMV-specific IgM. For four kidney transplant recipients, the occurrence of HCMV DNA in serum, virus isolation from urine and leukocytes, and HCMV IgG and IgM serology were determined. We found a correlation between HCMV DNA in serum and positive virus isolation from leukocytes. In three of five congenitally infected infants, HCMV DNA and HCMV IgM were detected in the same sample. Two other infants were HCMV DNA positive, although no HCMV IgM antibodies were measurable. HCMV was found in urine from these infants either by virus isolation or with the polymerase chain reaction. Serum from one of the 22 healthy HCMV-seropositive blood donors was HCMV polymerase chain reaction positive.     

Quantitative detection of herpes simplex virus DNA in the lower respiratory tract

Quantitation of herpes simplex virus (HSV) DNA in bronchoalveolar lavage specimens could indicate an infectious role in the lower respiratory tract. The aim of this study was to compare quantitative HSV DNA results from adult bronchoalveolar lavage specimens to clinical outcome. Quantitative real-time PCR assays targeting HSV and other herpes viruses were performed on adult bronchoalveolar lavage specimens obtained from a largely immunocompromised population during a 1-year period. The results were compared to patient characteristics and outcome. HSV DNA was detected in 11 (19%) of 57 bronchoalveolar lavage specimens with a mean viral level of 5.6 log genome equivalents/ml (range, 2.9-8.1 log). A threshold of HSV DNA levels equal or higher than 5.0 log (n = 7) was associated with mortality within 28 days following hospital admission (odds ratio [OR], 6.8; 95% confidence interval [CI], 1.2-39.2). A threshold level of 5.5 log was associated with mortality within 28 days of sampling (OR 8.5; 95% CI 1.2-62.1), only after excluding patients receiving specific antiviral medication. Patients with HSV DNA levels equal or higher than 7.5 log had severe respiratory failure. Viral pneumonia was histologically proven in one patient with 8.0 log at autopsy. No patient with HSV DNA levels below 5.5 log (n = 5) or DNA levels higher than 5.0 log of cytomegalovirus (CMV) (n = 3), Epstein-Barr virus (EBV) (n = 9), varicella-zoster virus (VZV) (n = 1), or human herpesvirus 6 (HHV-6) (n = 0) died within 28 days of hospital admission. We conclude that quantitative detection of HSV DNA in bronchoalveolar lavage fluid is a potential diagnostic tool for detection of relevant viral infection of the lower respiratory tract.     

Sensitive non-isotopic DNA hybridisation assay or immediate-early antigen detection for rapid identification of human cytomegalovirus in urine.

A sensitive non-radioactive DNA hybridisation assay employing digoxigenin-labelled probes was compared with immediate-early antigen detection and conventional virus isolation for the identification of human cytomegalovirus (HCMV) in 249 urine samples. Of 44 specimens yielding HCMV by virus isolation, more were positive by DNA hybridisation (32; 73%) than by immediate-early antigen detection (25; 52%) (P = 0.05). The specificity of the hybridisation assay in 45 apparently falsely positive specimens was supported by detection of HCMV DNA in 40 of these specimens using the polymerase chain reaction. Many urine specimens may thus contain large amounts of non-viable virus or free viral DNA. Evaluation of various protocols for the extraction and denaturation of virus DNA prior to hybridisation showed that proteinase K digestion with phenol/chloroform extraction was the most sensitive and reliable procedure. We conclude that the non-radioactive DNA hybridisation assay described is a potentially valuable routine diagnostic test.     

Markers of human immunodeficiency virus infection in pediatric bronchoalveolar lavage samples.

Pulmonary cells and fluid obtained by bronchoalveolar lavage (BAL) from 19 pediatric acquired immunodeficiency syndrome (AIDS) patients with pneumonia were examined for markers of human immunodeficiency virus (HIV-1) infection. The HIV-1 DNA was detected in BAL cells by polymerase chain reaction (PCR) in 14 of 15 patients (93.3 percent). Immunostaining of cytocentrifuged cell preparations of six specimens revealed that HIV-1 antigen was associated with from five percent to 95 percent of the alveolar macrophages. Analysis of the 22 cell-free BAL fluids by enzyme immunoassay (EIA) showed that samples from three patients (15.8 percent) contained HIV-1 p24 antigen. One sample, with a dilution factor of 15.1 relative to serum, contained a markedly elevated antigen concentration (106 pg per ml) compared to the serum concentration (41.6 pg per ml). Antibodies to HIV-1 were present in the BAL fluids of six patients (31.6 percent) at levels detectable by EIA. By Western blot analysis, three samples yielded more intense gp120 bands compared to bands observed with matched serum samples. Our results suggest that HIV-1 and antibodies to this virus are frequently present in the lungs of children with AIDS and that the serum antigen and antibody profile of some patients does not reflect local pulmonary levels.     

Incidence of human herpes virus-6 and human cytomegalovirus infections in donated bone marrow and umbilical cord blood hematopoietic stem cells

This study examined the incidence of human herpes virus-6 (HHV-6) and human cytomegalovirus (HCMV) infections that are potentially transmitted to haematopoietic stem cells (HSC) transplant recipients via bone marrow (BM) or umbilical cord blood (UCB). Bone marrow progenitor cells were collected from 30 allogenic BM donors. UCB HSC were collected from 34 subjects. The extracted DNA was then processed using nested polymerase chain reaction (nPCR) technique. HCMV and HHV-6 serological status were determined by enzyme immunoassay (EIA). Nested PCR identified HCMV in 22 (73%) of 30 samples of BM progenitor cells but in only eight (23.5%) of 34 samples of UBC HSC ( P = 0.001). HHV-6 DNA was detected in 11 (36.6%) of 30 BM progenitor cells and in only one (2.9%) of 34 UBC cells ( P = 0.002). Both HHV-6 and HCMV infections were determined in nine (26.5%) of 34 bone marrow samples. The results indicate that, the risk of HCMV and HHV-6 via BM progenitor cells is higher than transmission by UCB cells ( P= 0.04).     

Risk factors and clinical consequences of human herpesvirus 7 infection in paediatric haematopoietic stem cell transplant recipients

Human herpesvirus 7 (HHV-7) is the least studied beta-herpesvirus in transplant settings. This prospective study examined the activity of HHV-7 during the first 12 weeks post-stem cell transplant in 59 paediatric patients. The presence of HHV-7, human cytomegalovirus (HCMV) and human herpesvirus 6 (HHV-6) in blood was monitored weekly by a multiplex nested polymerase chain reaction. Overall, 33 (55.9%) patients had one or more surveillance blood sample(s) positive for HHV-7. In contrast to HCMV and HHV-6, no obvious peak time of reactivation was observed for HHV-7. The occurrence of HHV-7 DNAaemia showed a significant negative association with HHV-6 (P=0.022), but with no association with HCMV. A significant higher positive rate for HHV-7 was found in autologous versus allogeneic (P=0.002), and in peripheral blood versus umbilical cord/marrow (P<0.001) transplant. Acyclovir had no effect, whereas ganciclovir was associated with a lower rate of HHV-7 reactivation (P=0.009). One patient died of HHV-7 associated brain stem encephalitis. The administration of colony stimulating factor, occurrence of acute graft versus host disease, time to neutrophil and platelet engraftment showed no significant association with the occurrence of HHV-7 DNAaemia.     

Detection of human herpesvirus 7 (HHV-7) DNA in breast milk by polymerase chain reaction and prevalence of HHV-7 antibody in breast-fed and bottle-fed children

Twenty-nine breast milk mononuclear cell samples were analyzed for human herpesvirus 7 (HHV-7) DNA, human herpesvirus 6 (HHV-6) DNA, and human cytomegalovirus (HCMV) DNA by polymerase chain reaction (PCR). In addition, peripheral blood mononuclear cell samples from 13 puerperants were analyzed for HHV-7 DNA by PCR, and seropositivity of HHV-7 was also analyzed in breast-fed and bottle-fed children. HHV-7 DNA was detected in 3 of 29 breast milk samples. HCMV DNA was also detected in 3 of 29 breast milk samples, but HHV-6 DNA was not detected. HHV-7 DNA was detected in 11 of 13 samples of peripheral blood mononuclear cells. Though the seropositivity rate for HHV-7 in breast-fed children was slightly higher than that in bottle-fed children at 18 and 24 months old, the difference was not statistically significant. From these results, we speculate that breast-feeding may be one of the transmission routes of HHV-7, although this is not the main route. J. Med. Virol. 56:275–279, 1998. © 1998 Wiley-Liss, Inc.     

Human herpesvirus 6 and human herpesvirus 7 infections in renal transplant recipients and healthy adults in Turkey

Summary We explored the prevalence of human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) infections in 16 renal transplant recipients and 16 healthy controls by virus isolation, serology, polymerase chain reaction (PCR) followed by dot blot hybridization. HHV-6 variant A was isolated from one renal transplant recipient. Seven patients (44%) and six controls (38%) had HHV-6 variant B DNA in their peripheral blood mononuclear cells. The prevalence of HHV-7 DNA was found to be the same in patients and controls (19%).     

Increased expression of human herpesvirus 7 in lymphoid organs of AIDS patients.

BACKGROUND: Human herpesvirus 7 (HHV-7) interferes reciprocally with the human immunodeficiency virus (HIV) in CD4 T lymphocytes, as infection with HIV results in a down modulation of the CD4 molecule and inhibition of replication of HHV-7, and vice versa. Correlations between HHV-7 and HIV at the organ level have not been studied in detail. OBJECTIVE: To study the presence and cellular distribution of HHV-7 in lymphoid organs, i.e. lymph nodes (LNs) and spleen in AIDS patients and HIV-seronegative individuals. STUDY DESIGN: Cross-sectional study. The detection of HHV-7 specific antigen pp85, the 85 kDa encoded tegument phosphoprotein by U14 gene, was performed by immunohistochemistry (IHC) with a well characterized monoclonal antibody (mAb 5E1) to pp85. Nested polymerase chain reaction (PCR) was applied to detect HHV-7 specific DNA sequences. RESULTS: Cells infected with HHV-7 were detected in five of seven LNs from AIDS patients and in one of five LNs from HIV-seronegative patients. The infected cells were mainly macrophages. In samples from HIV-seropositive patients, a significantly higher number of HHV-7 infected cells could be observed than in specimens from HIV-seronegative patients. Neither the antigen nor DNA sequences of HHV-7 could be detected in spleen tissue from HIV-seronegative and AIDS patients. CONCLUSIONS: The data indicate that HHV-7 undergoes a higher extent of reactivation from latency and/or of replication under immunosuppression due to HIV-infection, similar to the other beta-herpesviruses HHV-6 and human cytomegalovirus (HCMV). The data further suggest that LNs, but not the spleen, may be a site of latency and consequently of reactivation of HHV-7 in AIDS patients.     

Detection and quantification of human herpesvirus 6 genomes using bronchoalveolar lavage fluid in immunocompromised patients with interstitial pneumonia

Human herpesviruses have been recognized as a pathogen involved in interstitial pneumonia (IP), especially in immunocompromised patients. So far, little is known about involvement of human herpesvirus 6 (HHV-6) in systemic respiratory tract disease. Currently, routine diagnostic tests for HHV-6 are inefficient for HHV-6 reactivation, therefore, we established a rapid quantification system of HHV-6 using real-time PCR in order to determine the possible role of human HHV-6 reactivation in immunocompromised patients showing IP. Bronchoalveolar lavage fluid (BALF) specimens were obtained from 84 consecutively treated patients with interstitial lung diseases (ILD) including various types of IP. First, we determined the viral burden in BALF and peripheral blood obtained from healthy volunteers. In healthy volunteers, the prevalence of HHV-6 in BALF was higher (4/12, 33.3%) than in peripheral blood (8/53, 15.1%), ranging from 0 to 101.65 HHV-6 genome copies per 1 microg of DNA. Among 84 patients with ILD analyzed, the prevalence of HHV-6 in BALF was 27.4% (23/84), ranging from 0 to 103.87 copies per 1 microg of DNA. Three specimens obtained from patients with collagen vascular disease, 2 from Hodgkin's disease, and 1 with sarcoidosis had high level of HHV-6 viral DNA, while none of the patients with idiopathic IP showed elevation of HHV-6 (more than 102) in BALF. Our results suggest that measurement of HHV-6 genomes in BALF using real-time PCR may be useful in management of the care of respiratory complications in immunocompromised patients.     

Detection of human cytomegalovirus pp67 late gene transcripts in cerebrospinal fluid of human immunodeficiency virus type 1-infected patients by nucleic acid sequence-based amplification

This study examined the clinical correlation between the presence of human cytomegalovirus (HCMV) pp67 mRNA in cerebrospinal fluid (CSF) and active HCMV central nervous system (CNS) disease in patients with human immunodeficiency virus type 1 (HIV-1). In total, 76 CSF specimens collected from 65 HIV-1-positive patients diagnosed with HCMV CNS disease, other non-HCMV-related CNS diseases, or no CNS disease were tested for the presence of HCMV pp67 mRNA using the NucliSens cytomegalovirus (CMV) pp67 assay (Organon Teknika, Durham, N.C.). The results were compared to those of a nested PCR for the detection of HCMV glycoprotein B DNA and to those obtained by viral culture (54 samples). CSF specimens collected from patients without HCMV CNS disease yielded the following results: pp67 assay negative, 62 of 62 specimens; culture negative, 41 of 41 specimens; and PCR negative, 56 of 62 specimens (6 specimens were positive). CSF specimens collected from patients with HCMV CNS disease yielded the following results: pp67 assay positive, 9 of 13 specimens; PCR positive, 13 of 13 specimens; and culture positive, 2 of 13 specimens. After resolution of the discordant results, the following positive and negative predictive values (PPV and NPV, respectively) for the diagnosis of HCMV CNS disease were determined. The PPV for PCR, pp67 assay, and culture were 68.4, 100, and 100%, respectively, and the NPV for PCR, pp67 assay, and culture were 100, 97.0, and 82. 7%, respectively. The sensitivities for DNA PCR, pp67 assay, and culture for the detection of HCMV were 100, 84.6, and 18%, respectively, and the clinical specificities were 90.5, 100, and 100%, respectively. This study indicates that the detection of HCMV pp67 mRNA in CSF has good correlation with active HCMV CNS disease, whereas CSF culture is insensitive and qualitative DNA PCR may detect latent nonreplicating virus in CSF from patients without HCMV CNS disease.     

Detection of human herpesvirus 6 DNA in throat swabs by polymerase chain reaction

The detection of human herpesvirus 6 (HHV-6) DNA was carried out in throat swabs of adults and children by the polymerase chain reaction, and isolation of virus was also attempted from peripheral mononuclear cells. Although virus was isolated only from peripheral blood mononuclear cells of infants with exanthem subitum, HHV-6 DNA was detected in one of 30 healthy adults (3%), two of nine adults (22%) with common cold, two of 10 infants (20%) with exanthem subitum, four of 39 febrile children (10%) with antibody to HHV-6 (including three of 10 infants aged under 1 year old, and one of 29 children aged over 1 year old). However, HHV-6 DNA was not detected in samples from healthy neonates.     

Coinfection of individual leukocytes with human cytomegalovirus and human immunodeficiency virus is a rare event in vivo

Infection with the human cytomegalovirus (HCMV) accelerates disease progression in human immunodeficiency virus 1 (HIV-1)-infected individuals. This has been attributed to the transaction of HIV-1 gene expression by HCMV gene products. For transactivation to be effective in vivo both viruses must be present in the same cell. We therefore examined blood samples from 13 HIV-1-infected patients with HCMV viremia for coinfection of individual leukocytes. In four of the patients lymph nodes were also examined. Multiple samples contained defined numbers (between 10 and 1000) of CD4⁺ lymphocytes or CD14⁺ monocytes were sorted by a FACS-based automated cell deposition unit. Samples were then analysed by a multiplex nested polymerase chain reaction, which can detect simultaneously HCMV and HIV DNA. The percentage of infected cells was calculated for each virus using the Poisson distribution. Between 0.43% and 6.2% of the CD4⁺ lymphocytes were infected with HIV and less than 0.15% with HCMV. The level of infection in CD14⁺ monocytes was always ≤0.11% for HIV and ranged between <0.05% and 0.58% for HCMV. Only seven of 1030 sorted samples from blood were positive for both viruses. In lymph nodes, none of the 144 samples tested were double-positive. This clearly shows that coinfection of individual human leukocytes with HIV and HCMV is a very rare event in vivo. Therefore, direct transactivation of HIV by HCMV in coinfected cells obtained from blood and lymph nodes may not explain the effect of HCMV on the prognosis of HIV-infected individuals. © 1996 Wiley-Liss, Inc.     

Impact assessment and investigation of factors associated with herpesviruses viremia in the first year of renal transplantation

The increased risk for opportunistic infections after a renal transplant requires monitoring of viral infections to avoid future complications. Our goal was to investigate the impact and factors associated with Epstein-Barr virus (EBV), human cytomegalovirus (HCMV) and human herpesvirus type 6 (HHV-6) viremia in renal transplant recipients. Whole blood samples were collected monthly from 82 patients during the first semester and then quarterly up to 1 year after transplantation. EBV, HCMV, and HHV-6 were detected and quantified by TaqMan real-time polymerase chain reaction. The results showed that EBV and HCMV viremia were detected in 32 patients (39% each), while HHV-6 viremia in only 3 patients (3.7%). EBV was significantly associated with age (P = .050), thymoglobuline induction (P = .019), mTOR inhibitor-based therapy (P = .003), and female gender (P = .044). HCMV was significantly associated with basiliximab induction (P = .015), mycophenolate mofetil (MMF)-based therapy (P = .003) and allograft acute rejection (P = .033). Moreover, HCMV-disease was correlated with MMF-based therapy (P = .021) and female gender (P = .003). In conclusion, EBV and HCMV viremia were associated with different immunosuppressive induction and maintenance strategies. Additionally, higher HCMV viremia (> 10 ⁴ copies/mL) was related to acute allograft rejection.     

Absence of human herpes virus 8 in semen from healthy Danish donors.

Epidemiological data indicate a sexual route of transmission of acquired immune deficiency syndrome (AIDS) associated Kaposi's sarcoma. Recently human herpes virus 8 (HHV-8) has been proposed as the aetiological agent for development of Kaposi's sarcoma. Further the virus has been reported in semen obtained from healthy men. In Denmark strict biochemical and microbiological criteria are used in combination with an intensive interview to select semen donors. Despite these strict criteria, HHV-8 may be transmitted to a recipient and even the child by the use of donor semen. We used four different polymerase chain reaction (PCR) and one nested PCR to test semen from 100 Danish donors for the presence of HHV-8 DNA. All 100 samples were consistently negative for HHV-8 DNA, while only one sample (1%) was positive for cytomegalovirus DNA. As HHV-8 was not demonstrated in any of the semen samples, we conclude that the frequency of HHV-8 in semen from Danish donors is very low.     

Human herpesvirus-6: A survey of presence and distribution of genomic sequences in normal brain and neuroglial tumors

In an attempt to study the frequency and distribution of human herpesvirus-6 (HHV-6) infection both in normal and neoplastic brain tissues in vivo, polymerase chain reaction was used to look for HHV-6 genomes: 1) in samples, obtained at necropsy, from different regions of the brain of immunocompetent adult subjects and of patients who died of AIDS; 2) in the surgical biopsies of a well-characterized series of primary brain tumors of neuroglial origin. HHV-6-specific sequences were identified in six of nine brain samples from immunocompetent subjects, and in four of seven brain samples from AIDS patients. Viral sequences were identified in the specimens derived either from the grey (frontal cortex and basal ganglia) or from the periventricular white matter. HHV-6 DNA was found only in 6 of the 37 primary brain tumor biopsies examined. This study provides for the first time molecular evidence of a wide distribution of HHV-6 infection in the brain tissues of a high proportion of subjects, both in normal and in impaired immunity. In this large series of tumor biopsies the presence of HHV-6 genomic sequences is a rare phenomenon, arguing against a major role of this herpesvirus in the pathogenesis of primary brain tumors of neuroglial origin in immunocompetent subjects. © 1995 Wiley-Liss, Inc.