Presence of human beta- and gamma-herpes virus DNA in Hodgkin's disease.

Herpes viruses have been implicated in the etiology of Hodgkin's disease (HD). We studied the prevalence of human cytomegalovirus (CMV), human herpes viruses type-6 (HHV-6), type-7 (HHV-7) and type 8 (HHV-8) DNA in up to 88 Hodgkin's disease biopsies in comparison to Epstein-Barr virus (EBV) DNA by polymerase chain reaction (PCR). Non-Hodgkin lymphomas (NHL) and reactive lesions served as controls. CMV and HHV-6 were found in 8/86 (9%) and 11/88 (13%) HD cases, respectively, by nested primer PCR. Except for three cases harbouring HHV-6 type-B, only HHV-6 type-A was detected in HD. HHV-7 was observed by nested PCR in 33/88 (38%) HD cases and was already detectable in 15/88 (17%) HD cases by a single-round PCR indicating elevated virus copy numbers. Seven of these cases showed co-infection with HHV-6, and 11 cases were found to contain EBV DNA. 7/8 CMV-positive HD cases also harboured EBV DNA. HHV-8 DNA was not detected by single round or nested PCR in any HD case investigated. Thus, CMV, HHV-6, and HHV-7 were present in small proportions of HD cases, with frequent co-infection of HHV-6 and HHV-7, and frequent association with EBV. In contrast to EBV, beta-herpes viruses are therefore unlikely to have a role in the aetiology of HD. Rather, the presence of these viruses seems to reflect impaired immunological surveillance.

Identification of human cytomegalovirus variants by analysis of single strand conformation polymorphism and DNA sequencing of the envelope glycoprotein B gene region-distribution frequency in liver transplant recipients.

Single strand conformation polymorphism analysis (SSCP) of PCR-amplified DNA and subsequent DNA sequencing of human cytomegalovirus (HCMV) glycoprotein B (gB) gene were applied to identify known HCMV strains and to detect new virus variants. 61 HCMV PCR positive patients were studied out of a cohort of 410 patients after liver transplantation (LTX). SSCP was able to distinguish between strains Davis, AD169, and Towne, and in addition could identify five new virus variants (Berlin B, C, E, F, and H). Their frequency, gB and gH types were determined. Simultaneous infections with two or three strains or variants, as well as a switch from one virus to another virus were observed during long-term follow-up. No correlation between the occurrence of certain virus strains or gB types and defined clinical manifestations of HCMV infection after LTX was drawn.

Human herpesvirus type 6 variants identified by single-strand conformation polymorphism analysis.

Six human herpesvirus 6 (HHV-6) variants were analyzed for heterogeneity using the polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP). Two independent DNA regions were selected: a fragment of the gene U11 (position 18966-21578) coding for a basic phosphoprotein, the major antigenic structural protein pp100; and a fragment from an open reading frame (ORF) area of the gene U67, previously referred to as 13R (position 102458-103519), coding for a product of unknown function. The two PCR systems based on the above DNA sequences yielded products of 187 bp and 223 bp, respectively. DNA obtained from three laboratory reference strains (U1102, R104 and St.W.) and from HHV-6 infected peripheral white blood cells of bone marrow transplant patients and blood donors was used to test the applicability of two different SSCP analysis systems for the identification of HHV-6 variants using amplicons derived by PCR from the two genomic regions described above (U11 [pp100], U67 [13R-ORF]). The generation of characteristic SSCP patterns enables the rapid differentiation of HHV-6 A and B strains for the classification of variants derived from clinical samples, reducing the need for expensive and time-consuming direct sequencing analyses.

Human herpesvirus type 7 in blood donors: detection by the polymerase chain reaction.

In order to evaluate the prevalence of human herpesvirus type 7 (HHV-7) in adult blood donors oral lavage fluid, buffy coat, and urine samples from 112 persons were examined by the polymerase chain reaction (PCR) at one time point. In addition, 11 donors were studied longitudinally over 11 weeks. When the results of the initial and the longitudinal study were combined HHV-7 DNA was found in samples from 109 of 112 (97.3%) adult blood donors. On the basis of different sensitivity levels of the first and the nested PCR differences were detected in the viral DNA load in the samples. It was found that lavage fluid regularly carried significantly higher DNA concentrations than buffy coat. Out of 112 donors, 102 (91.1%) and 8 (7.1%) were positive in the first, less sensitive PCR in lavage fluid and buffy coat, respectively (P < .0001). After nested PCR, 107 (95.5%) and 74 (66.1%) were positive in lavage fluid and buffy coat, respectively (P < .0001). Urine samples were found positive only sporadically. The longitudinal study showed that the oral lavage fluid of most of the donors consistently carried HHV-7 over up to 53 weeks, whereas buffy coat samples were positive less often. In conclusion, HHV-7 is found frequently in adult blood donors in the oral lavage fluid and buffy coat, which are, therefore, potential sources of HHV-7 transmission.

Comparison of polymerase chain reaction from plasma and buffy coat with antigen detection and occurrence of immunoglobulin M for the demonstration of cytomegalovirus infection after liver transplantation.

We compared the value of PCR on plasma with PCR on buffy coat leukocytes, Ag assay, and the determination of IgM antibodies by ELISA for the diagnosis and follow-up of cytomegalovirus infection. Thirty patients were followed after liver transplantation (LTX). We compared the tests to assess their clinical usefulness. Fourteen of 30 (46%) patients were both positive in plasma and buffy coat PCR and Ag test. Sixteen patients were negative in both procedures. There was a 97.2% concordance between PCRs done from plasma or buffy coat. The concordance of results of PCR and Ag test in single samples was 94.3%. Discordant results were found in 5.6% of samples. Discordance was observed in the early and the late phase of CMV infection and was due to positive PCRs preceding positive Ag tests for 1-3 weeks in one-half of the patients. IgM antibodies were first observed after a median period of 8 weeks (range, 6-11 weeks) after LTX. Positive PCRs and Ag tests preceded clinical manifestation of CMV disease by a 1 week median (range, 0-3 weeks), whereas positive IgM ELISAs occurred after a median period of 2.5 weeks (range, 0-4 weeks) after the onset of CMV disease. The sensitivity and specificity of both PCR and Ag test were identical, 100% and 76%, respectively. However, for the IgM ELISA, the sensitivity was only 66%, and the specificity was 84%. In conclusion, plasma or buffy coat PCR and Ag test are equally reliable procedures for early detection and monitoring of CMV infection. PCR can become positive earlier than the Ag test, but it is technically more demanding to perform. The demonstration of IgM antibodies is of little practical help because an antibody response occurs too late in relation to infection.

Detection of herpesvirus type 6 by polymerase chain reaction in blood donors: random tests and prospective longitudinal studies.

In order to evaluate the prevalence of HHV-6 in blood donors, we examined 112 persons by polymerase chain reaction (PCR) and ELISA. HHV-6 antibodies could be detected in 107/111 (96.4%) of the donors. The median ELISA antibody level was 0.451 (range 0.056-0.914). 14 individuals (12.5%) were PCR positive in either oral lavage fluid, urine or buffy coat. Six persons (5.4%) were PCR positive in buffy coat samples. The prospective longitudinal analysis of 11 donors for periods between 7 and 13 weeks revealed that 4/6 persons who were initially PCR negative had positive tests in 9/63 weeks studied. Two persons were consistently PCR positive over the whole observation period of 12 and 13 weeks. HHV-6 variants could be determined in 14 persons as variant A in nine and variant B in five cases. These observations emphasize the high prevalence of HHV-6 and suggest that some blood donors carry detectable concentrations of the virus and therefore may be a source for transmission of HHV-6. The finding of positive PCR in antibody negative individuals suggests that antibody determination may not be sufficient to identify potentially infectious persons.

Overexpression of the Raf-1 proto-oncogene in human myeloid leukemia.

The Raf-1 protein, a cytoplasmic serine/threonine kinase, plays an important role in signal transduction pathways. In order to examine the role of Raf-1 in human myeloid leukemia, we determined raf-1 mRNA expression by Northern blot analysis in blast cell samples from 27 acute myeloid leukemia (AML) cases and peripheral blood mononuclear cells from six healthy donors. A normal raf-1 transcript size was detected in all cases investigated. However, overexpression of raf-1 mRNA was found in 2 of 27 AML cases, both of which were erythroleukemias (AML, FAB M6).

Herpesvirus type 6 in patients undergoing bone marrow transplantation: serologic features and detection by polymerase chain reaction.

To evaluate the potential role of human herpesvirus type 6 (HHV-6) infection in patients after bone marrow transplantation (BMT) we sequentially analyzed buffy coat leukocytes, oral lavage fluid, and urine from 57 patients for the presence of HHV-6 DNA by polymerase chain reaction (PCR) before and after 60 BMTs. Twenty-four patients undergoing autologous BMT and 36 with allogeneic BMT were studied. Thirty-six patients (60%) were PCR positive in one or more tests. The majority of PCR-positive patients had positive results only sporadically, in 1 (n = 23) or 2 weeks (n = 5). Six patients were positive in 3 to 5 weeks. In 2 patients, we found a high frequency of positive tests, in 7 of 7 and 10 of 10 weeks analyzed. Twenty-four patients (40%) remained PCR negative throughout the post-BMT period. There was a significant correlation between the results of HHV-6 PCR and the occurrence of acute graft-versus-host disease (aGVHD). In grade II-IV, 6 of 8 (75%) patients had 2 or more positive PCR tests, compared with 5 of 25 (20%) patients without or with grade I aGVHD (P = .01). There was no difference in the outcome of PCR tests with respect to the type of BMT or pre-BMT HHV-6 enzyme-linked immunosorbent assay titers. Restriction enzyme analysis of PCR amplificates from 18 patients showed HHV-6 variant B in 16 (88.9%) and variant A in 2 cases (11.1%). We conclude that HHV-6 DNA can be detected in 60% of the patients after BMT. HHV-6 DNA can be detected more frequently in patients with moderate and severe aGVHD than in patients without aGVHD or with mild aGVHD.

Demonstration of cytomegalovirus after bone marrow transplantation by polymerase chain reaction, virus culture and antigen detection in buffy coat leukocytes.

We prospectively monitored buffy coat leukocytes of 47 patients after 50 marrow transplantations (autologous n = 18, allogeneic n = 32) by polymerase chain reaction (PCR) for the presence of cytomegalovirus (CMV). None of the 18 autologous graft recipients (9 seropositive, 9 seronegative) had positive PCR results or CMV disease throughout the post-transplantation course. Six of 32 allograft recipients (19 seropositive, 13 seronegative) became PCR positive, four of whom developed CMV disease. PCR positive patients were found more often (5 of 10) in the group with acute GVHD grade II-IV compared with 1 of 22 in the group without or with grade I acute GVHD (p = 0.002). Comparison of PCR with antigen assay and virus culture showed an agreement in 90 of 96 (94%) samples. Discordant results were due to a higher sensitivity of the PCR compared with antigen assay (n = 4) and virus culture (n = 6). In conclusion, PCR helps to identify those patients who will not develop CMV disease and narrows down the number of patients who eventually will suffer symptomatic CMV infection. Furthermore, PCR is a useful tool for following the post-transplantation course with respect to CMV and for judging the effect of antiviral treatment.

A potential role for human herpesvirus type 6 in nervous system disease.

Human herpesvirus type 6 (HHV-6) is a new representative of the herpesvirus family which was associated with a spectrum of diseases, including myalgic encephalitis, meningitis and the chronic fatigue syndrome. We set out to study the potential role of HHV-6 in multiple sclerosis (MS) (n = 21), facial palsy (FP) (n = 19) and Guillain-Barré-syndrome (GBS) (n = 7). Results were compared with a control group (CG) (n = 16). We analyzed paired samples of serum and cerebrospinal fluid (CSF) with the polymerase chain reaction (PCR) for the presence of HHV-6 DNA. The studies were complemented by ELISA determination of serum antibodies against HHV-6. In the MS group we detected HHV-6 DNA in the CSF from three of 21 (14.3%) patients but not in the corresponding serum samples. In FP, GBS and controls CSF and serum PCRs were negative in all cases. HHV-6 serum antibody titers were significantly higher in MS compared with FP, GBS and controls. These findings suggest that HHV-6 may play a role in MS.

Demonstration of cytomegalovirus by polymerase chain reaction after liver transplantation.

The polymerase chain reaction (PCR) is a highly sensitive and specific technique for detection of cytomegalovirus DNA. With this method we prospectively analyzed buffy coat leukocytes at weekly intervals over 3 months in 60 patients after liver transplantation (LTX). The PCR results were correlated with the pretransplant donor/recipient CMV antibody status and with the occurrence of CMV-induced disease. Thirty-three of 60 (55%) patients became PCR-positive during their posttransplant course. None of the 27 patients with permanent negative PCRs developed CMV disease. Of 33 patients with positive PCRs, 13 (39%) became ill. CMV disease developed in 9 of 22 (41%) antibody-negative recipients but only in 4 of 38 (10%) seropositive graft recipients. The incidence of CMV disease was 75% (9 of 12 patients) in seronegative recipients who converted to positive PCR results and 19% (4 of 21 patients) in seropositive patients with positive PCR findings. The predictive value of a positive PCR was 75% in seronegative patients but it was low (19%) in seropositive recipients. The predictive value of a negative PCR is 100%. Thus, PCR determinations are useful in identifying patients who will not develop CMV disease and in narrowing down the number of individuals who will become sick. Further, PCR is a helpful tool in the follow-up of patients under antiviral treatment.

Demonstration of chimerism after allogeneic bone marrow transplantation by polymerase chain reaction of Y-chromosome-specific nucleotide sequences--characterization of a new technical approach.

Various techniques are applied to assess chimerism after allogeneic bone marrow transplantation. The polymerase chain reaction (PCR) of donor- and/or host-specific gene sequences provides a rapid and highly sensitive technique. We describe the characterization and application of PCR for the amplification of Y-chromosome-specific DNA in blood cells recovered from stored slides. Four different primer pair combinations were used. PCR can be rapidly performed on stained or unstained slide material with varying sensitivity--depending on the primer combination. The lowest limit of detection is one male cell in 500-1000 female cells. The technique was applied to follow the early post-transplant course of 15 male patients who received grafts from female donors and found a high incidence of mixed chimerism during the first three months after BMT and a striking fluctuation between positive and negative results in the follow-up of individual patients. We conclude that PCR for the detection of male-specific DNA sequences can be successfully performed with high sensitivity on material recovered from stored blood slides.

Formation and stability of interstrand cross-links induced by cis- and trans-diamminedichloroplatinum (II) in the DNA of Saccharomyces cerevisiae strains differing in repair capacity.

Four haploid yeast strains differing in proficiency for DNA repair were treated with cis- or transDDP. The wild type was least sensitive while the excision-deficient mutants rad1, rad2 and snm1 exhibited higher sensitivities to either platinum compound. In all four strains tested cisDDP showed a two- to five-fold higher cytotoxicity than equimolar concentrations of transDDP. DNA interstrand cross-linking was caused by both agents in all strains. However, transDDP introduced more DNA cross-links at exposure times up to 6 h while cisDDP was the more active cross-linking agent at longer times. There was no clear-cut correlation of the number of DNA interstrand cross-links with survival. Formaldehyde-treated cells showed DNA with lower buoyant density due to proteinase K sensitive DNA-protein cross-linking; this effect was not observed after treatment with either platinum compound. Post-treatment incubation of wild-type cells exposed to cisDDP led to degradation of DNA by single and double-strand breaks, parallel with further increase of DNA interstrand cross-linking. DNA from transDDP-treated cells did not show extensive degradation although interstrand cross-links were lost during liquid holding.