Malin Enbom

Absence of seven human herpesviruses, including HHV-6, by polymerase chain reaction in CSF and blood from patients with multiple sclerosis and optic neuritis

Several members of the herpesvirus family have been implicated in the pathogenesis of multiple sclerosis (MS). Recently, HHV‐6 viral antigen has been demonstrated in association to MS plaques, as well as DNA from human herpesvirus 6 (HHV‐6) in cerebrospinal fluid from a few MS patients by polymerase chain reaction (PCR). In the present study, CSF from patients with MS, optic neuritis and other neurological diseases, as well as consecutive CSF and serum samples from MS patients included in a clinical trial with acyclovir, were analysed by nested PCR for the presence of DNA from herpes simplex virus 1 and 2, Epstein‐Barr virus, varicella zoster virus, cytomegalovirus, human herpesvirus 6 and 7. No virus DNA was found in any CSF (n= 115) or serum (n= 116) sample. These findings argue against a continuous disseminated herpesvirus infection in MS, but do not rule out a lesion‐associated, low‐grade herpesvirus infection within the MS brain.

Viral Load of Human Herpesvirus 8 in Peripheral Blood of Human Immunodeficiency Virus-Infected Patients with Kaposi's Sarcoma

ABSTRACT Viral load is an important marker of activity of viral diseases for a number of viruses. We wished to evaluate whether the viral load of human herpesvirus 8 (HHV-8) in peripheral blood was a consistent feature of Kaposis sarcoma (KS) patients and whether the viral load correlated with human immunodeficiency virus (HIV) RNA levels, CD4 counts, and/or the HHV-8 seroreactivity. Fifty-four consecutive plasma samples from 14 patients with KS were evaluated for HHV-8 viral load by quantitative real-time PCR. Samples were analyzed at the start of highly active antiretroviral therapy (HAART) and at different intervals during treatments. The median HHV-8 DNA load before HAART treatment was 8,998 (ranging from 170 to 40,100) copies/ml and 12,270 (ranging from 40 to 142,575) copies/ml during HAART. There were both increasing and decreasing trends. There was an association between HHV-8 DNA and HIV RNA viral loads (odds ratio [OR] = 5.40; 95% confidence interval [95% CI], 1.54 to 18.98) and between HHV-8 viral load and CD4 cell counts (OR = 7.24; 95% CI, 1.30 to 40.35). High HHV-8 viral load was also correlated with the titers of antibodies to the lytic HHV-8 antigen detected with immunofluorescence (P < 0.01), but not with antibodies to the latent HHV-8 antigen. In conclusion, we found that HHV-8 viremia in KS is associated with HIV viral load, CD4 cell counts, and lytic HHV-8 serological reactivity. HHV-8 viral load monitored by real time PCR might be useful for determination HHV-8 viral load during the follow-up of KS patients.

Detection of Epstein-Barr virus, but not human herpesvirus 8, DNA in cervical secretions from Swedish women by real-time polymerase chain reaction.

Background Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV-8) are two related herpesviruses that may be sexually transmitted. Goal To examine the presence of HHV-8 and EBV DNA in the female genital tract. Study Design Real-time polymerase chain reaction systems for quantification of DNA from HHV-8, EBV, and herpes simplex virus type 2 were developed and used for examination of cervical secretions from 112 Swedish women. HHV-8, EBV, and herpes simplex virus type 2 serology was also performed on samples from all subjects. Results EBV DNA was found in 10 cervical secretion samples, sometimes in high amounts. No cervical secretion or leukocyte sample contained detectable HHV-8 DNA. Antibodies to HHV-8-latent and -lytic antigens were found in 2.7% and 24% of serum samples, respectively. Conclusion This study supports a possible sexual route of transmission for EBV but not for HHV-8. The new real-time polymerase chain reaction systems could be valuable in future studies of relations between virus load and disease.

Seroprevalence of viral childhood infections in Eritrea.

BACKGROUND The seroprevalence of viral childhood infections in Africa has not been thoroughly investigated. The relatively recently discovered human parvovirus B19 (B19) and human herpesvirus 6 (HHV-6) have received particularly little attention. OBJECTIVE To investigate the seroprevalence of viral childhood infections in different Eritrean populations and to define groups at high risk for infection. STUDY DESIGN Five population groups in Eritrea have been examined to define the prevalence of specific antibodies to several childhood viruses. The study population of more than 400 persons consisted of children, pregnant women, female sex workers and members of a secluded tribe called Rashaida. RESULTS All groups showed a high prevalence of antibodies to measles and HHV-6 (> 85%). For rubella, the seroprevalence was very high in all adult groups (93-99%) except the Rashaida group (71%). The mumps prevalence was surprisingly low in the Rashaida group (29%) compared to 46-85% in the other adults. Late encounter of mumps and rubella was also observed among the Rashaidas. The pattern of antibodies to B19 showed a higher seroprevalence in all groups (56-91%) compared to what has been reported from the western world. CONCLUSION The findings represent what might be expected in an unvaccinated population. The exception was the Rashaidas, which had low seroprevalences and late encounter of mumps and rubella. This is of importance because it makes this tribe vulnerable to these infections, which are associated with complications when acquired in adult age. Also noteworthy is the high frequency of antibodies to HHV-6 and particularly B19 in all groups, indicative of an early encounter of both these viruses.

Antibodies to human herpesvirus 8 latent and lytic antigens in blood donors and potential high-risk groups in Sweden: variable frequencies found in a multicenter serological study.

Human herpesvirus 8 (HHV‐8) is a herpesvirus associated with Kaposis sarcoma (KS). An immunofluorescence assay was used for detection of IgG, IgM, and IgA antibodies against lytic and latent HHV‐8 antigens to analyse samples from KS patients (n = 8), healthy blood donors (n = 162), individuals with a high risk sexual behaviour (n = 114), and bone marrow transplant patients (with high risk for bloodborne infections) (n = 34) in Sweden. Of the KS patients, 88% had IgG antibodies to both lytic and latent antigens by immunofluorescence. In all other groups, antilatent antibodies were rare (0–2.6%). IgG antibodies to the lytic antigens were found, by immunofluorescence, in 20% of the blood donors, 31% of the high risk patients, and in 24 and 29% of the bone marrow transplant patients (pre‐ and post‐transplant samples, respectively). For verification of the specificity of the anti‐lytic antibodies, 170 of the samples were also tested blindly at different laboratories world‐wide with five other assays shown previously to detect HHV‐8 antibodies in most KS patients. By using two recombinant HHV‐8 proteins (ORF65/vp17 and K8.1/gp 35‐37) in ELISA, a whole‐virion ELISA and two immunofluorescence assays confirmation of the reactivity against lytic viral antigens was sought. The comparison of the different methods suggested the K8.1 ELISA to be highly specific and also showed a good agreement between two of the immunofluorescence assays. However, generally there was a poor correlation for positive results, indicating the need of further methodological development. J. Med. Virol. 62:498–504, 2000.

Epstein‐Barr virus DNA in serum after liver transplantation ‐ surveillance of viral activity during treatment with different immunosuppressive agents

In immunocompromised HIV-infected and transplanted patients, there is a risk of developing Epstein-Barr virus (EBV)-associated lymphoproliferative disorders (LPD) and lymphomas. EBV has previously been detected by the polymerase chain reaction (PCR) in cerebrospinal fluid from all AIDS patients with EBV-associated cerebral lymphomas. We therefore thought it would be of interest to determine whether transplant patients with extracerebral EBV-associated LPD have detectable EBV genomes in serum. Nested PCR (nPCR) showed that 58% (18/31) of liver transplant (LTX) patients had EBV DNA in 17% (21/125) of serum samples obtained within the first 3 months after LTX. In 39% (7/18) of the patients, the first EBV nPCR-positive sample was found within 2 weeks post-LTX. Basic immunosuppression with cyclosporin A or FK506 did not seem to influence the frequency of detectable EBV genomes in serum. In contrast, positive EBV nPCR correlated to secondary OKT3 treatment for severe acute rejection (P=0.009). EBV-associated malignant lymphoma developed in three patients 2–6 months post-LTX. In all of them, EBV DNA was amplifiable within 12–14 days after LTX. The EBV antibody titers were not directly related to detectable EBV DNA in serum. We conclude that monitoring of LTX patients receiving increased immunosuppression by nPCR for EBV DNA in serum may help in the early identification of those at risk of developing EBV-associated LPD.

Seroprevalence of human herpes virus 8 in different Eritrean population groups

BACKGROUND Human herpesvirus 8 (HHV-8) is associated with Kaposis sarcoma. In the US and Europe, HHV-8 is believed to be mainly sexually transmitted, but reports from some African countries suggest non-sexual transmission. OBJECTIVES To find out more about HHV-8 seroprevalence and transmission in Eastern Africa. STUDY DESIGN In this study, 411 serum samples from different population groups in Eritrea (children, pregnant women, female sex workers and members of the isolated Rashaida tribe) were examined for HHV-8 antibodies with an immunofluorescence assay detecting antibodies to latent and lytic HHV-8 antigens. RESULTS Antibodies to HHV-8 latent antigen were found in 0-2% of Eritrean children, 5% of pregnant women, 8% of female sex workers and 26% of Rashaidas, respectively. No correlation was found between detectable HHV-8 antibodies and seropositivity to HIV or herpes simplex 2. CONCLUSIONS These results suggest that HHV-8 infection is relatively common in Eritrea and that viral transmission occurs predominantly through non-sexual route in this region.