Serum Antibodies Against the Oncogenic Merkel Cell Polyomavirus Detected by an Innovative Immunological Assay With Mimotopes in Healthy Subjects

Merkel cell polyomavirus (MCPyV), a small DNA tumor virus, has been detected in Merkel cell carcinoma (MCC) and in normal tissues. Since MCPyV infection occurs in both MCC-affected patients and healthy subjects (HS), innovative immunoassays for detecting antibodies (abs) against MCPyV are required. Herein, sera from HS were analyzed with a novel indirect ELISA using two synthetic peptides mimicking MCPyV capsid protein epitopes of VP1 and VP2. Synthetic peptides were designed to recognize IgGs against MCPyV VP mimotopes using a computer-assisted approach. The assay was set up evaluating its performance in detecting IgGs anti-MCPyV on MCPyV-positive (n=65) and -negative (n=67) control sera. Then, the ELISA was extended to sera (n=548) from HS aged 18-65 yrs old. Age-specific MCPyV-seroprevalence was investigated. Performance evaluation indicated that the assay showed 80% sensitivity, 91% specificity and 83.9% accuracy, with positive and negative predictive values of 94.3% and 71%, respectively. The ratio expected/obtained data agreement was 86%, with a Cohen's kappa of 0.72. Receiver-operating characteristic (ROC) curves analysis indicated that the areas under the curves (AUCs) for the two peptides were 0.82 and 0.74, respectively. Intra-/inter-run variations were below 9%. The overall prevalence of serum IgGs anti-MCPyV in HS was 62.9% (345/548). Age-specific MCPyV-seroprevalence was 63.1% (82/130), 56.7% (68/120), 64.5% (91/141), and 66.2% (104/157) in HS aged 18-30, 31-40, 41-50 and 51-65 yrs old, respectively (p>0.05). Performance evaluation suggests that our indirect ELISA is reliable in detecting IgGs anti-MCPyV. Our immunological data indicate that MCPyV infection occurs asymptomatically, at a relatively high prevalence, in humans.

Characterization of BK Polyomaviruses from Kidney Transplant Recipients Suggests a Role for APOBEC3 in Driving In-Host Virus Evolution

BK polyomavirus (BKV) frequently causes nephropathy (BKVN) in kidney transplant recipients (KTRs). BKV has also been implicated in the etiology of bladder and kidney cancers. We characterized BKV variants from two KTRs who developed BKVN followed by renal carcinoma. Both patients showed a swarm of BKV sequence variants encoding non-silent mutations in surface loops of the viral major capsid protein. The temporal appearance and disappearance of these mutations highlights the intra-patient evolution of BKV. Some of the observed mutations conferred resistance to antibody-mediated neutralization. The mutations also modified the spectrum of receptor glycans engaged by BKV during host cell entry. Intriguingly, all observed mutations were consistent with DNA damage caused by antiviral APOBEC3 cytosine deaminases. Moreover, APOBEC3 expression was evident upon immunohistochemical analysis of renal biopsies from KTRs. These results provide a snapshot of in-host BKV evolution and suggest that APOBEC3 may drive BKV mutagenesis in vivo.

Absence of JC polyomavirus (JCPyV) viremia in early post-transplant JCPyV nephropathy: A case report

JC polyomavirus (JCPyV)-associated nephropathy (JCPyVAN) occurs in <3% of PVAN cases after renal transplantation. We report the first confirmed case to our knowledge of JCPyVAN diagnosed by kidney biopsy in the early 6 months post transplant in Thailand. In this case report, recovery of renal allograft function was not observed after reduction of immunosuppressive agents and administration of intravenous immunoglobulin and cidofovir. Despite persistent JCPyV viruria, no significant further decline in allograft function was documented at 15 months post transplant.

Serum biomarkers of polyomavirus infection and risk of lung cancer in never smokers

BACKGROUND

Lung cancer in never smokers is a significant contributor of cancer mortality worldwide. In this analysis, we explored the role of nine human polyomaviruses, including JC virus (JCV), BK virus (BKV) and Merkel cell virus (MCV), in lung cancer development in never smokers as there are data to support that polyomaviruses are potentially carcinogenic in the human lung.

METHODS

We used multiplex serology to detect serum antibodies to polyomaviruses in a nested case-control design combining lung cancer cases and controls from four cohort studies - NYU Women's Health Study (NYU-WHS), Janus Serum Bank, Shanghai Women's Health Study and Singapore Chinese Health Study (SCHS).

RESULTS

The final analyses included 511 cases and 508 controls. Seroprevalence for each polyomavirus showed significant heterogeneity by study, but overall there were no statistically significant differences between cases and controls. In total, 69.1% of the cases and 68.7% of the controls were seropositive for JCV VP1 antibody. Seropositivity for BKV was higher at 89.0% in cases and 89.8% in controls and lower for MCV at 59.3% in cases and 61.6% in controls. Similar results were obtained after adding an additional retrospective case-control study (Xuanwei study) to the analysis.

CONCLUSIONS

Our results do not support the hypothesis that seropositivity for polyomaviruses is associated with increased lung cancer risk in never smokers. Future research to evaluate relationship between polyomavirus infection and lung carcinogenesis should focus more on evaluating the presence of virus or viral nucleic acids (DNA or RNA) in lung tumour samples.

Specific Antibodies Reacting with SV40 Large T Antigen Mimotopes in Serum Samples of Healthy Subjects

Simian Virus 40, experimentally assayed in vitro in different animal and human cells and in vivo in rodents, was classified as a small DNA tumor virus. In previous studies, many groups identified Simian Virus 40 sequences in healthy individuals and cancer patients using PCR techniques, whereas others failed to detect the viral sequences in human specimens. These conflicting results prompted us to develop a novel indirect ELISA with synthetic peptides, mimicking Simian Virus 40 capsid viral protein antigens, named mimotopes. This immunologic assay allowed us to investigate the presence of serum antibodies against Simian Virus 40 and to verify whether Simian Virus 40 is circulating in humans. In this investigation two mimotopes from Simian Virus 40 large T antigen, the viral replication protein and oncoprotein, were employed to analyze for specific reactions to human sera antibodies. This indirect ELISA with synthetic peptides from Simian Virus 40 large T antigen was used to assay a new collection of serum samples from healthy subjects. This novel assay revealed that serum antibodies against Simian Virus 40 large T antigen mimotopes are detectable, at low titer, in healthy subjects aged from 18–65 years old. The overall prevalence of reactivity with the two Simian Virus 40 large T antigen peptides was 20%. This new ELISA with two mimotopes of the early viral regions is able to detect in a specific manner Simian Virus 40 large T antigen-antibody responses.

Clinical validation study of quantitative real-time PCR assay for detection and monitoring of BK virus nephropathy

BK virus (BKV) causes nephropathy (BKVN) in renal transplant patients, but monitoring of BKV loads provides an opportunity to prevent BKVN. However, because viral load measurement is not standardized, each laboratory must validate their methodology. We performed a retrospective analysis of 1371 plasma and 600 urine BKV loads measured by the laboratory developed real-time polymerase chain reaction (RT-PCR) of BKV DNA and 346 biopsies from 284 patients in our renal transplant program. We assessed the ability of plasma and urine viral loads to predict the presence of BKVN in biopsy using the receiver-operator characteristic curve. We determined that the cut-offs 3.7 and 7.2 log copies/ml have the best sensitivity (100% and 100%) and specificity (97.6% and 97.5%) for the detection of concurrent biopsy with BKVN by plasma and urine viral load, respectively. Also, we determined that the presence of at least two viral loads greater than 2.8 log copies/ml for plasma and 6.4 log copies/ml for urine within 30 days of biopsy can detect BKVN with similar operating characteristics. Lastly, among pairs of urine and plasma viral loads from the same day, we found that 375 of 376 urine viral loads <4 log copies/ml were accompanied by plasma viral loads <2.6 log copies/ml, a finding which can alleviate the need for plasma viral load for most patients. In summary, our RT-PCR of BKV DNA has good operating characteristics, and our findings above can help in development of a better strategy to monitor BKV.

Serological evidence of an early seroconversion to Simian virus 40 in healthy children and adolescents

At present Simian virus 40 (SV40) infection in humans appears to be transmitted independently from early contaminated vaccines. In order to test the spread of SV40 infection in children, an immunologic assay employing specific SV40 synthetic peptides corresponding to its viral protein (VP) antigens was employed to estimate the seroprevalence of this polyomavirus in Italian infants and adolescents. Serum samples from 328 children and adolescents, up to 17 years, were investigated. Serum antibodies against SV40 VPs were detected by indirect enzyme-linked immunosorbent assays. The seroprevalence of this polyomavirus was calculated after stratifying the subjects by age. Anti-viral capsid protein 1-2-3 SV40 IgG antibodies were detected in 16% of the study participants. The prevalence of antibodies against SV40 VPs tended to increase with age in children, up to 10 year old (21%). Then, in the cohort of individuals aged 11–17 years, the prevalence decreased (16%). A higher prevalence rate (23%) of SV40 VP antibodies was detected in the cohorts of 1–3 year and 7–10 year old children, than in children and adolescents of the other age groups. This age corresponds to children starting nursery and primary school, respectively, in Italy. IgM antibodies against SV40 VP mimotopes were detected in 6–8 month old children suggesting that SV40 seroconversion can occur early in life. SV40 VP antibodies are present at low prevalence in Italian children (16%), suggesting that SV40 infection, although acquired early in life, probably through different routes, is not widespread. The low SV40 seroprevalence suggests that SV40 is less transmissible than other common polyomaviruses, such as BKV and JCV. Alternatively, our immunologic data could be due to another, as yet undiscovered, human polyomavirus closely related to SV40.

Trichodysplasia spinulosa-associated polyomavirus (TSV) and Merkel cell polyomavirus: correlation between humoral and cellular immunity stronger with TSV

Merkel Cell Polyomavirus (MCV) is a common infectious agent likely to be involved in the pathogenesis of most Merkel cell carcinomas (MCC). Trichodysplasia spinulosa-associated polyomavirus (TSV), which exhibit high seroprevalence in general population, has been detected in trichodysplasia spinulosa (TS) skin lesions suggesting an etiological role for this disease. Previous studies have shown strong MCV-specific T-cell responses, while no data exist on T-cell immunity against TSV. In order to characterize Th-cell immunity against TSV, and to allow comparisons with the MCV-specific Th-cell immunity, we studied TSV-specific proliferation, IFN-γ, IL-10 and IL-13, and MCV-specific IFN-γ and IL-10 responses in 51 healthy volunteers, and in one MCC patient. Recombinant TSV and MCV VP1 virus-like particles (VLPs) were used as antigens. A significant correlation was found between virus-specific Th-cell and antibody responses with TSV; with MCV it proved weaker. Despite significant homology in amino acid sequences, Th-cell crossreactivity was not evident between these viruses. Some subjects seronegative to both TSV and MCV exhibited Th-cell responses to both viruses. The agent initially priming these Th-cells remains an enigma. As CD8⁺ cells specific to MCV T-Ag oncoprotein clearly provide an important defense against established MCC, the MCV VP1-specific Th-cells may, by suppressing MCV replication with antiviral cytokines such as IFN-γ, significantly contribute to preventing the full process of oncogenesis.

Surveillance and modification of immunosuppression minimizes BK virus nephropathy

BACKGROUND/AIMS

Infection of a transplanted kidney with the polyomavirus, BK, is associated with poor allograft survival.

METHODS

In an attempt to prevent this transplant complication, we studied 144 consecutive transplant recipients for the presence of BK infection with plasma and urine PCR testing at 1, 2, 3, 6 and 12 months. Viruria alone was followed by serial studies. If plasma PCR became positive at >2.6 log copies, mycophenolate was reduced until there was no detectable plasma viral load.

RESULTS

Urine PCR was positive in 34 (24%), while plasma PCR turned positive in 22 cases (15%). No patients developed viremia with <6.8 log copies in the urine. Viremia resolved within 3 months or less in 20 of 22 patients after reduction of immunosuppression. Surveillance biopsies at 2 and 6 months revealed no BK nephropathy. Eight patients had acute rejection during reduced immunosuppression; however, all of these reversed with pulse steroids. Patient and graft survival at 1 year was 99 and 98%, respectively. Use of the cell-mediated immunity assay (ImmuKnow, Columbia, Md., USA) was not useful in identifying infected patients.

CONCLUSION

Active surveillance for BK virus by urine/plasma PCR with prompt reduction in immunosuppression can prevent BK nephropathy.

Hawaii cohort study of serum micronutrient concentrations and clearance of incident oncogenic human papillomavirus infection of the cervix

The degree to which the resolution of human papillomavirus (HPV) infection parallels exposure to other factors, particularly those related to nutritional status, is a relatively unexplored area of research. We established a cohort of women for long-term follow-up to examine the association of serum retinol, carotenoid, and tocopherol concentrations with the clearance of incident cervical HPV infection. Interviews and biological specimens were obtained at baseline and at 4-month intervals. At each visit, a cervical cell specimen for HPV DNA analysis and cytology and a fasting blood sample to measure micronutrient levels were collected. A Cox proportional hazards model was used to study the relationship between clearance of 189 incident (type-specific) oncogenic HPV infections and the levels of 20 serum micronutrients among 122 women. Higher circulating levels of trans-zeaxanthin, total trans-lutein/zeaxanthin, cryptoxanthin (total and beta), total trans-lycopene and cis-lycopene, carotene (alpha, beta, and total), and total carotenoids were associated with a significant decrease in the clearance time of type-specific HPV infection, particularly during the early stages of infection (<or=120 days). HPV clearance time was also significantly shorter among women with the highest compared with the lowest serum levels of alpha-tocopherol and total-tocopherol, but significant trends in these associations were limited to infections lasting <or=120 days. Clearance of persistent HPV infection (lasting >120 days) was not significantly associated with circulating levels of carotenoids or tocopherols. Results from this investigation support an association of micronutrients with the rapid clearance of incident oncogenic HPV infection of the uterine cervix.

Acceleration to Death from Liver Cancer in People with Hepatitis B Viral Mutations Detected in Plasma by Mass Spectrometry

Liver cancer is the leading cause of cancer death in many regions of the world. With the goal to discover biomarkers that reflect subsets of high-risk individuals and their prognosis, we nested our study in a male cohort of 5,581 hepatitis B surface antigen carriers in Qidong, People's Republic of China, who were recruited starting in 1989. By December 2003, 667 liver cancer cases were diagnosed in this group and plasma samples collected at the initial screening at enrollment were available in 515 cases who had succumbed to liver cancer. Hepatitis B virus (HBV) DNA could be isolated in 355 (69%) of these samples. In 14%, 15%, 19%, 31%, and 22%, screening took place at < or = 1.5, 1.51 to 3, 3.01 to 5, 5.01 to 9, and > 9 years before death, respectively; and 39% died at age below 45 years. The relation between mutations in HBV and time to death were determined by logistic regression for the odds of mutation and by survival analyses methods with age as the time scale. In 279 (79%) of these individuals, the samples contained a two-nucleotide 1762T/1764A HBV mutation. Sixteen samples lacking the 1762T/1764A mutation had novel mutations elsewhere in the 1761 to 1767 region of the HBV genome. There was a statistically significant difference (P = 0.012) for the high prevalence of the HBV mutations in the men who died from hepatocellular carcinoma under the age of 45 years relative to those who died after 55 years of age and HBV mutations accelerated death (relative hazard, 1.40; 95% confidence interval, 1.06-1.85) and that the effect was attenuated by age from 2.04 for age 35 years to 1.0 for age 65 years with the 90% confidence band being above 1 for ages < 50 years. These findings provide a conceptual framework to explain the acceleration of mortality in individuals infected with HBV.

A Prospective Longitudinal Study of Polyomavirus Shedding in Lung‐Transplant Recipients

BACKGROUND

Polyomavirus infection causes renal dysfunction after kidney transplantation, but it has not been thoroughly investigated in nonrenal solid-organ transplantation.

METHODS

Fifty lung-transplant recipients provided prospective urine and blood samples over the course of 17 months. Samples were analyzed for BK virus (BKV), JC virus (JCV), and simian virus 40 (SV40) using conventional polymerase chain reaction (PCR), sequence analysis, and quantitative real-time PCR.

RESULTS

Thirty-one (62%) of 50 patients had polyomavirus detected in at least 1 urine specimen, including 16 (32%) for BKV, 12 (24%) for JCV, and 6 (12%) for SV40. Mean BKV loads (5.0 log(10) copies/mL) did not differ from those of JCV (5.7 log(10) copies/mL; P=.38), but SV40 loads (2.5 log(10) copies/mL) were lower than those of BKV (P=.006) and JCV (P=.002). Blood samples were negative. Infection with individual polyomaviruses or polyomavirus infection in aggregate was not associated with reduced creatinine clearance. Patients not shedding polyomavirus had better survival than patients shedding polyomavirus (P=.049).

CONCLUSIONS

Polyomaviruses BKV and JCV were commonly detected in urine from lung-transplant recipients. SV40 was found in 12% of patients but was shed at a lower frequency and with lower viral loads than the other viruses. Polyomavirus infection was not associated with renal dysfunction.

Isolated heart and liver transplant recipients are at low risk for polyomavirus BKV nephropathy

BACKGROUND

BKV infection and nephropathy is a significant cause of allograft dysfunction in kidney transplantation. BKV viremia, rather than viruria, corresponds to BKV nephropathy. The prevalence of BKV viremia in non-renal solid organ transplants has not been systematically evaluated.

METHODS

We determined prevalence of BKV viremia in kidney, combined kidney-heart, kidney-liver, kidney-pancreas, kidney-heart-liver, and heart and liver transplant recipients using BKV-PCR.

RESULTS

Seven out of 173 (4%) kidney transplant recipients had BKV viremia, with BKV>2 x 10(5) copies/mL in 6/7 and 1.9 x 10(3) in the remaining one patient. BKV viremia was not found in 24 heart transplant recipients, whereas 1/37 (2.7%) liver transplants showed low copy numbers (< or =10(3)). BKV-PCR< or =10(3) copies/mL were also found in one of each combined kidney-heart and kidney-liver transplant recipients. BKV nephropathy was proven by biopsy in 4/6 patients with high BKV viral loads. All six patients showed renal dysfunction, requiring reduction in immunosuppression and antiviral therapy. All four patients with low BKV viral loads (1.9 x 10(3) or < or =10(3)) showed stable renal function after reduction of immunosuppression or no treatment, respectively.

CONCLUSION

Higher BKV levels in plasma are associated with renal dysfunction. Kidney transplant recipients are at high risk compared with recipients of isolated heart or liver allografts, for development of BKV nephropathy.

Generation of virus-like particles consisting of the major capsid protein VP1 of goose hemorrhagic polyomavirus and their application in serological tests

Goose hemorrhagic polyomavirus (GHPV) is the causative agent of hemorrhagic nephritis and enteritis of geese (HNEG), a fatal disease of young geese with high mortality rates. GHPV cannot be efficiently propagated in tissue culture. To provide antigens for diagnostic tests and vaccines, its major structural protein VP1 was recombinantly expressed in Sf9 insect cells and in the yeast Saccharomyces cerevisiae. As demonstrated by density gradient centrifugation and electron microscopy, GHPV-VP1 expressed in insect cells formed virus-like particles (VLPs) with a diameter of 45 nm indistinguishable from infectious polyomavirus particles. However, efficiency of VLP formation was low as compared to the monkey polyomavirus SV-40-VP1. In yeast cells, GHPV-VP1 alone formed smaller VLPs, 20 nm in diameter. Remarkably, co-expression of GHPV-VP2 resulted in VLPs with a diameter of 45 nm. All three types of GHPV-VLPs were shown to hemagglutinate chicken erythrocytes. ELISA and hemagglutination inhibition tests using the VLPs as antigen detected GHPV-specific antibodies in up to 85.7% of sera derived from flocks with HNEG but in none of the sera of a clinically healthy flock. However, GHPV-specific antibodies were also detected in sera from two other flocks without HNEG indicating a broad distribution of GHPV due to subclinical or unrecognised infections.

The prevalence of BK viremia and urinary viral shedding in a pediatric renal transplant population: a single-center retrospective analysis

Polyomavirus-induced nephropathy has emerged as an important cause of renal graft dysfunction. Limited pediatric data are available for this disease. We therefore reviewed the results of the first year of polyomavirus screening in our pediatric renal transplant recipients to determine the prevalence of polyomavirus viremia and urinary shedding. Screening included detection of polyomavirus in plasma by polymerase chain reaction (PCR) and in urine by electron microscopy (EM). In patients with a positive screening test, an assessment of graft dysfunction was made. Fifty-two patients met the inclusion criteria. Urinary EM was performed in 205 samples and polyomavirus was detected in 10 patients, representing 19% of the study population. PCR was performed on 222 samples and was positive for the BK virus in plasma from seven patients or 13.4% of the study population. Eight patients had a positive screening test and increased creatinine. All these patients underwent renal transplant biopsy. This revealed evidence of polyomavirus nephropathy in four patients. Our findings reveal a high prevalence of polyomavirus in both urine and plasma that is frequently associated with graft dysfunction. These findings support the routine screening of pediatric post-renal transplant patients for polyomavirus replication.

Prevalence and molecular characterization of the polymerase gene of gibbon lymphocryptovirus

BACKGROUND

Lymphocryptovirus (LCV) is found in various non-human primates. As a herpesvirus naturally infecting gibbons it is closely related to human Epstein-Barr virus (EBV) with which it shares considerable genetic, biological and epidemiologic features.

METHODS

We collected blood samples from 70 gibbons (51 Hylobates lar, 18 Hylobates pileatus and 1 Hylobates agilis) for further separation into serum and peripheral blood mononuclear cells (PBMC).

RESULTS

Only 13 of 70 (18.6%) sera were serologically positive for human EBV IgG but 64 of 70 (91.4%) PBMCs yielded the partial LCV DNA polymerase gene by semi-nested PCR, which we subjected to direct sequencing. All sequences showed 84% nucleic acid and 91% amino acid identity to human EBV. Phylogenetic tree analysis demonstrated gibbon LCVs clustered separately from other gammaherpesvirinae but closely related to LCV of other species.

CONCLUSIONS

Based on LCV DNA detection, we discovered a high prevalence of LCV infection among gibbons. Further characterization of non-human primate LCV might thus provide new insight into both evolution and pathogenicity of gammaherpesvirinae.

BK virus nephritis after renal transplantation

BK viremia and nephritis are increasing problems in renal transplant recipients. The exact cause of the increasing prevalence of this condition remains poorly understood. Increasing prevalence has been correlated with newer immunosuppressive agents and the decline in acute rejection rates in recent years. The clinical manifestation varies from the asymptomatic state of viremia and nephritis to clinical renal dysfunction. The diagnosis of this infection is based on the combination of the presence of urinary decoy cells, virus in the urine/blood, and typical renal histological findings of interstitial nephritis. Routine post-transplant screening for BK viremia and viruria prior to the occurrence of nephritis and the reduction in immunosuppressive therapy for subjects with viremia appear to be attractive approaches. The treatment of BKV nephritis (BKVN) consists of reduction in immunosuppressive therapy and antiviral therapy with cidofovir or leflunomide or a combination of both. Approximately 30-60% of subjects with BKVN experienced irreversible graft failure. However, in recent years, the combinations of early detection, prompt diagnosis, and appropriate reduction in immunosuppressive therapy have been associated with better outcome. The pathogenesis of BK virus infection in renal transplant recipients needs to be explored. The source of BKV infection (donor as opposed to recipient), the role of host humoral, and cellular immunity to BKV, and the role of alloimmune activation in renal graft to the occurrence of nephritis are discussed in this review.

Antibodies against bovine herpesvirus 4 are highly prevalent in wild African buffaloes throughout eastern and southern Africa

Bovine herpesvirus 4 (BoHV-4) has been isolated from cattle throughout the world. Interestingly, a survey of wild African buffaloes mainly from the Maasai Mara Game Reserve in Kenya revealed that 94% of the animals tested had anti-BoHV-4 antibodies [Rossiter, P.B., Gumm, I.D., Stagg, D.A., Conrad, P.A., Mukolwe, S., Davies, F.G., White, H., 1989. Isolation of bovine herpesvirus-3 from African buffaloes (Syncerus caffer). Res. Vet. Sci. 46, 337-343]. These authors also proposed that the serological antigenic relationship existing between BoHV-4 and alcelaphine herpesvirus 1 (AlHV-1) could confer to BoHV-4 infected buffaloes a protective immune response against lethal AlHV-1 infection. In the present study, we addressed two questions related to Rossiter et al. paper. Firstly, to investigate the role of the African buffalo as a natural host species of BoHV-4, the seroprevalence of anti-BoHV-4 antibodies was analysed in wild African buffaloes throughout eastern and southern Africa. A total of 400 sera was analysed using two complementary immunofluorescent assays. These analyses revealed that independently of their geographical origin, wild African buffaloes exhibit a seroprevalence of anti-BoHV-4 antibodies higher than 68%. This result is by far above the seroprevalence generally observed in cattle. Our data are discussed in the light of our recent phylogenetic study demonstrating that the BoHV-4 Bo17 gene has been acquired from a recent ancestor of the African buffalo. Secondly, we investigated the humoral antigenic relationship existing between BoHV-4 and AlHV-1. Our results demonstrate that among the antigens expressed in AlHV-1 infected cells, epitope(s) recognised by anti-BoHV-4 antibodies are exclusively nuclear, suggesting that the putative property of BoHV-4 to confer an immune protection against AlHV-1 relies on a cellular rather than on a humoral immune response.

Detection and quantitation of BK virus DNA by real-time polymerase chain reaction in the LT-ag gene in adult renal transplant recipients

Determination of polyomavirus BK (BKV) load in urine and plasma has been advocated for monitoring adult renal transplant recipients suffering from BKV-related nephropathy. An "in-house" real-time quantitative PCR assay was developed using the BKV-1/BKV-3 primers set in the large tumor antigen (LT-ag) region to quantitate BK virus loads in plasma and urine in renal transplant patients. This assay was adapted to routine virology laboratory by evaluating two extraction procedures of nucleic acids from urine and plasma, one manual and the other using an automatic extractor, and by evaluating the Light Cycler versus Taqman apparatus. Both the manual and automatic extraction procedures and real-time PCR apparatus were equivalent. The Light Cycler and Taqman instruments allow similarly rapid, accurate, reproducible and specific quantitative detection of the three major BKV subtypes, with a detection limit of 10 BKV DNA copies/ml, and a range from 10(0) to 10(7) copies/ml. Of 855 renal transplant patients, 128 (15%) had BKV DNA in both plasma and urine samples with a mean viral load of 5.1 log/ml in plasma and 6.8 log/ml in urine and in 5 (4%) BKV-associated tubulo-interstitial nephropathy; 332 (39%) BKV DNA was found only in the urine, not in the plasma, without further development of nephropathy and 395 patients had no BKV in plasma and urine. These observations emphasize the usefulness of real-time PCR to assess the BKV load by routine testing, and confirm the need to combine both plasma and urine determinations of the BKV DNA load in order to identify renal transplant patient at high risk for BKV-associated nephropathy.

HPV-16 L1 VLP vaccine elicits a broad-spectrum of cytokine responses in whole blood

Here, we evaluated innate and adaptive immune system cytokine responses induced by HPV-16 L1 VLP in whole blood (WB) cultures from individuals receiving the vaccine (n=20) or placebo (n=4) before and after vaccination. 11 cytokines were measured: IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IFN-gamma, TNF-alpha, and GM-CSF using multiplex bead arrays. Cytokine profiles from WB samples clearly discriminated between vaccine and placebo recipients and between pre and post-vaccination responses. Significant increases in Th1, Th2 and inflammatory cytokines were observed in WB assays following vaccination. Results from WB assays were compared against parallel PBMC-based assays in a subset of patients. Differences between whole blood assay and PBMC were observed, with the highest levels of induction found for WB for several cytokines. Our results indicate that multiplex assays for cytokine profiling in WB are an efficient tool for assessing broad spectrum, innate and adaptive immune responses to vaccines and identifying immunologic correlates of protection in efficacy studies.

Polyomavirus nephropathy: morphology, pathophysiology, and clinical management

PURPOSE OF REVIEW

Viral nephropathies, particularly those caused by polyomaviruses of the BK-virus strain, are serious complications following renal transplantation. The review will highlight the morphological, pathophysiological and clinical aspects of BK-virus nephropathy. New patient management strategies are discussed.

RECENT FINDINGS

Immunosuppression with tacrolimus and mycophenolate-mofetil promotes the activation of latent BK-virus in the urinary tract and increases the odds ratio for developing BK-virus nephropathy significantly. A productive infection with BK-viruses shows viral replication in tubular epithelial cells and acute tubular injury. BK-virus nephropathy can be further complicated by concurrent acute rejection episodes contributing to graft demise. Risk assessment after transplantation and patient management during ongoing viral nephropathy have undergone revision by the introduction of real time quantitative polymerase chain reaction techniques measuring BK-virus genome load fluctuations in the serum. Treatment strategies for BK-virus nephropathy include not only low-dose immunosuppression but also drugs with antiviral effects: cidofovir and leflunomide. Transient anti-rejection therapy, including anti-lymphocytic preparations, is a therapeutic option in cases of BK-virus nephropathy and concurrent acute rejection. Recent advances in patient management strategies have resulted in markedly improved graft survival. In cases of graft loss due to BK-virus nephropathy, re-transplantation should be considered.

SUMMARY

BK-virus nephropathy is a significant complication following renal transplantation. Recent advances have improved our understanding of the morphological changes, potential risk factors and patient management strategies would be optimized. The availability of quantitative viral load measurements now offers the opportunity for a more accurate and timely clinical intervention.

Hepcidin excess induces the sequestration of iron and exacerbates tumor-associated anemia

The iron-regulatory hormone hepcidin has been proposed as the mediator of anemia of inflammation (AI). We examined the acute and chronic effects of hepcidin in the mouse. Injections of human hepcidin (50 μg/mouse), but not of its diluent, induced hypoferremia within 4 hours. To examine the chronic effects of hepcidin, we implanted either tumor xenografts engineered to overexpress human hepcidin or control tumor xenografts into nonobese diabetic-severe combined immunodeficiency (NOD-SCID) mice. Despite abundant dietary iron, mice with hepcidin-producing tumors developed more severe anemia, lower serum iron, and increased hepatic iron compared with mice with control tumors. Hepcidin contributes to AI by shunting iron away from erythropoiesis and sequestering it in the liver, predominantly in hepatocytes. (Blood. 2005;105:1797-1802)

BKV-DNA and JCV-DNA Co-Quantification Assay to Evaluate Viral Load in Urine and Serum

Infections from human polyomaviruses BK and JC (BKV and JCV) occur independently, but concomitant infections and the simultaneous persistence of both viruses have been observed in renal transplant recipients. Several studies have disclosed a correlation between BKV and interstitial nephritis in renal transplant recipients, and an association between JCV and some cases of nephropathy has recently been hypothesized. This article describes the development of a semiquantitative-nested polymerase chain reaction (PCR) assay to simultaneously detect BKV and JCV viral load in urine and serum. The first-round amplification step uses primers that amplify a 385-bp DNA fragment from the "large T antigen" region of both viruses. Samples testing positive in the first step are then run in the second step. In the second-round amplification, different inner primers are used to separately quantify BKV-DNA and/or JCV-DNA. The assay offers several advantages including: (1) rapid submission of clinical samples to screening; (2) verification of the absence of Taq polymerase inhibitors with the use of an internal control; (3) a sensitivity threshold of 10 copies/reaction; and (4) assay running is less labor intensive, cheap, and easy to perform. The assay may be easily used to monitor viral loads versus baseline levels in urine and serum samples from renal transplant recipients to detect those at risk of BKV- or JCV-related nephropathy, and to monitor their response to immunosuppression reduction therapy if it occurs.

Polyomavirus BK-specific immunity after kidney transplantation

Failure to mount or maintain a protective immune response may influence the development of polyomavirus BK (BKV)-associated nephropathy (PVAN). However, limited data are so far available on BKV-specific immunity after kidney transplantation. BKV-specific cellular immune response was retrospectively analyzed in kidney recipients with or without BKV infection/reactivation by measuring the frequency of interferon (IFN)-gamma-secreting cells in peripheral blood. Patients with BKV-active infection and good renal function (n=6) had a mean BKV-specific lymphocyte frequency 2 log lower than healthy controls and in the same range as BKV-seropositive recipients without active infection (n=7). Patients with PVAN (n=5) revealed undetectable levels of BKV-specific cells. However, two patients from the latter cohort treated with immunosuppression reduction showed the emergence of specific immunity, with IFN-gamma production in the same range as healthy controls. Our preliminary data suggest that lack of protective immunity toward BKV may favor the occurrence of BKV active infection and influence the progression to PVAN.

Polyomavirus infection in pediatric renal transplant recipients: evaluation using a quantitative real-time PCR technique

Polyomavirus infection and related nephropathy is being increasingly recognized as an important cause of allograft dysfunction in adult renal transplant recipients. We prospectively monitored pediatric renal transplant recipients for the presence of BK and JC polyomavirus in urine and blood using a quantitative PCR assay to evaluate the prevalence and clinical relevance of polyomavirus infection in the pediatric renal transplant population. Of 46 pediatric renal recipients who were evaluated, nine (20%) demonstrated isolated BKV viruria, while five (11%) had concomitant BKV viremia and viruria. JCV viruria was found in eight (17%) patients. BKV viremia was associated with a significantly higher urinary BKV viral load: median urinary viral load 1.9 x 10(9) copies/mL (range 6.7 x 10(2)-1.8 x 10(11)) for the group with concomitant viremia and viruria vs. 1.8 x 10(3) copies/mL (range 2.5 x 10(2)-4.5 x 10(6)) for the group with isolated viruria (p < 0.0001). In children that were followed prospectively since their transplantation, the BKV urinary viral load increased markedly before viremia became detectable a few weeks later. None of the patients with JCV viruria or isolated BKV viruria had renal dysfunction. Among the five patients with BKV in both urine and blood, two developed biopsy-proven BKV nephropathy associated with deterioration of the renal function. Management of the BKV nephropathy consisted of reduction of immunosuppression alone or in combination with antiviral treatment with cidofovir. This study shows that polyomavirus infection and related interstitial nephritis is a relevant clinical issue in the pediatric renal transplant population. Monitoring the polyomaviral load in the urine and the blood of the patients using a quantitative PCR technique is a useful tool in the diagnosis and subsequent management of this infection. Even before viremia is present, an important rise in the urinary viral load should draw the attention of the transplant clinician and raise the issue of adapting the immunosuppression.

Characterization of the Herpesvirus saimiri Orf51 protein

Herpesvirus saimiri (HVS) is a gamma(2)-herpesvirus sharing genomic colinearity and a high degree of functional homology with HHV-8. To begin exploring the correlates of HVS infectivity and neutralization, we designed and implemented a new reporter assay. Using this assay, we could demonstrate that HVS neutralizing antibodies are present at high levels in naturally infected squirrel monkeys and are strongly induced after pathogenic, experimental infection of common marmosets. Further, we demonstrated that viral entry is influenced by cellular glycosaminoglycans and that, similar to HHV-8, soluble heparin is capable of blocking infectivity. We next cloned and characterized the positional homologue of HHV-8 K8.1, HVS Orf51. N-glycosidase F treatment indicates that like K8.1, Orf51 is a glycoprotein. Found in the viral particle, it localizes to the endoplasmic reticulum of expressing cells. Like K8.1, Orf51 could bind to agarose-conjugated heparin, implicating this molecule in viral attachment to cells. These studies provide the groundwork for additional experiments into the role that this protein may be playing in viral pathogenicity, persistence, and cell tropism.

Gender differences in sexual biomarkers and behaviors associated with human papillomavirus-16, -18, and -33 seroprevalence

BACKGROUND

The elevated risk for incident head and neck cancer among human papillomavirus (HPV)-16-seropositive individuals has substantiated a role for HPV in the etiology of head and neck cancers. The relationship between HPV seroreactivity and prevalent oral HPV infection in men and women without cancer has yet to be investigated.

GOAL

The goal of this study was to evaluate a possible association between oral HPV infection and HPV seroreactivity after adjustment for gender, sexual behaviors, and sexually transmitted disease.

STUDY DESIGN

A cross-sectional study of factors associated with HPV-16, -18, and -33 seroreactivity was performed in a population of 586 men and women with and without HIV infection. Antibodies in sera were measured by use of a virus-like protein (VLP)-based enzyme-linked immunosorbent assay. Exfoliated cells from the tonsillar and oral mucosa were analyzed for the presence of 38 mucosal HPV types by polymerase chain reaction.

RESULTS

Women had significantly greater seroreactivity for all HPV types investigated when compared with men (odds ratio, 4.3; 95% confidence interval, 3.0-6.0). Seroprevalence was greatest in men and women aged 35 to 45 years. Tonsillar HPV infection, oral sex with men, and HIV infection were independently associated with HPV seroreactivity in men after adjustment for age and number of sexual partners. In women, HSV-2 seropositivity and a history of sexually transmitted diseases were similarly important. Oral and tonsillar HPV infection were not associated with HPV seroreactivity in women.

CONCLUSION

HPV seropositivity is associated with sexually transmitted diseases among women and possibly mucosal HPV exposures in men. Tonsillar HPV infection could impact seroprevalence, particularly in men.

Comparison of plasma Epstein-Barr virus (EBV) DNA levels and serum EBV immunoglobulin A/virus capsid antigen antibody titers in patients with nasopharyngeal carcinoma

BACKGROUND

Serologic measurement of antibodies to Epstein-Barr virus (EBV) immunoglobulin A/viral capsid antigen (IgA/VCA) and early antigen (IgA/EA) has been used widely to screen for nasopharyngeal carcinoma (NPC) in China. Recently, it was found that plasma EBV DNA concentration is an indicator for the staging and prognosis of patients with NPC. To determine whether there is a correlation between plasma EBV DNA levels and serum levels of IgA/VCA, the authors measured both in patients with NPC and in a control group.

METHODS

Real-time polymerase chain reaction was used for quantitative analysis of plasma EBV DNA concentration, and enzyme-linked immunoadsorbent assay was used to measure EBV VCA/IgA in patients with primary NPC (n = 120 patients), locally recurrent NPC (n = 8 patients), and distant metastatic NPC (n = 21 patients) among 76 patients with NPC after the completion of radiotherapy, in 60 patients with NPC in clinical remission, in 38 patients with non-NPC tumors, and in 47 control individuals.

RESULTS

The median plasma EBV DNA levels were 6200 copies/mL, 9200 copies/mL, and 2050 copies/mL in patients with primary, locally recurrent, and distant metastatic NPC, respectively, but declined to 0 copies/mL in patients with clinically remissive NPC, in patients who completed radiotherapy, in patients with non-NPC tumors, and in the control group. In contrast, EBV VCA/IgA titers and detection rates remained high in all NPC groups. Plasma EBV DNA levels were significantly higher in patients who had serum VCA/IgA titers > or = 1:640 (median, 83,450 copies/mL) compared with the levels in patients who had titers < or = 1:320 (median, 17,200 copies/mL). Patients with NPC who had advanced TNM stage (Stages III and IV; median, 8530 copies/mL) and T classification (T3 and T4 tumors; median, 8530 copies/mL) had significantly higher plasma EBV DNA levels compared with patients who had early TNM stage (Stages I and II; median, 930 copies/mL) and T classification (T1 and T2 tumors; median, 3700 copies). Patients who had advanced TNM stage NPC had significantly higher mean VCA/IgA titers (1:424) compared with patients who had early TNM stage NPC (1:246), but there was no correlation between IgA/VCA titer and T or N classification of NPC.

CONCLUSIONS

The results suggest that plasma EBV DNA detection is a more sensitive and specific marker than the serum IgA/VCA titer for the diagnosis and monitoring of patients with NPC. These findings provide convincing evidence for the use of plasma EBV DNA measurements for the early diagnosis and staging of NPC as well as for monitoring recurrence and metastasis of this tumor.

Human papillomavirus DNA in sera of cervical cancer patients as tumor marker

Persistent infection with human papillomavirus (HPV) has been widely recognized to induce carcinoma of the uterine cervix. Viral DNA has been documented to occur as tumor DNA in the circulation of patients with primary tumors caused by viral infection. The aim of this study was to evaluate the utility of serum HPV DNA as tumor marker in cervical cancer patients. Sera taken from 94 cervical cancer patients at the date of diagnosis and follow-up serum samples from 24 patients were examined for HPV DNA using PCR enzyme immunoassay. Serum samples taken at the date of diagnosis were HPV DNA positive in 45% of all investigated samples. Sera which were HPV DNA positive at the time of diagnosis became and also remained negative after primary treatment in patients without recurrence or persistent disease. HPV DNA was positive up to 423 days before the time of clinical diagnosis of recurrence in 10 out of 13 cases (median 72 days, range 0-423 days). Serum HPV DNA seems to reflect biological activity of the tumor. Our results indicate that serum HPV DNA might be a useful additional marker for early detection of recurrence in cervical cancer patients.

Cytokines and Epstein Barr virus (EBV) genes expression in blood chronic lymphocytic leukaemia (CLL) cells and their immortalised CLL cell lines

We have encountered two unique chronic lymphocytic leukaemia (CLL) patients, PG and NN. Some blood CLL cells of these patients have been infected and carry Epstein Barr virus (EBV) in vivo. In spite of their early-activated G0/G1 stage of post germinal center (GC) memory cells, ex vivo EBV-carrying blood CLL cells of PG clone expressed LMPs and used specific QUK splice for their EBNA1 expression, similar to the EBV-carrying cells of non-B origin. Interestingly, EBV-carrying CLL cells of NN clone expressed LMP2a and used UK-splice for their EBNA1 expression, similar to the in vivo EBV-carrying high density normal B cells in the blood of healthy individuals. The CLL-derived lines but not normal lymphoblastoid cell line (LCL) used QUK- and YUK-splice for their EBNA1 expression. As expected, LCL and their permanent CLL-derived lines used Cp promoter and up-regulated their EBNA2 expression. Blood CLL cells and the CLL-derived cell lines of these patients spontaneously produced cytokines as shown by microarray assay. The types and quantities of cytokines might relate to their CLL origin and viral strain in the given CLL cells. Neither blood CLL nor their CLL-derived cell lines express any detectable apoptosis-inducer ligands, CD95L or Apo 3L. As a consequence of cell cycle progression, CLL-derived cell lines up-regulated their co-stimulator molecules CD80 and apoptosis-related receptor CD95. Since only the rare EBV-carrying CLL cells grew in vitro, the combination of viral genome and cytokines seems to be critical for the outgrowth of EBV-carrying CLL cells over their EBV-negative counterpart in vitro but not in vivo.

EBV specific antibody-based and DNA-based assays in serologic diagnosis of nasopharyngeal carcinoma

We assessed 5 EBV specific assays for their capacity to effect serologic diagnosis of suspected NPC. The assays were the immunofluorescent assays, VCA IgA and EA IgA, the enzyme-linked immunosorbent assays specific for EBNA 1 IgA or zta IgG and an EBV DNA assay. Serum samples were taken from 218 symptomatic NPC patients presenting consecutively at a public hospital in Hong Kong, 51 of whom were subsequently diagnosed as having NPC; 4 had EBV-associated lung cancer with similar serology as NPC. The remaining patients included 23 who had other cancers and 140 who had other diseases. Objectives of serodiagnosis under such clinical settings, therefore, are to both exclude and predict a diagnosis of NPC. None of the assays individually can meet both requirements adequately, however. The difficulty was best overcome by combining EBNA 1 IgA and zta IgG. It was shown that 68.3% of the patients gave a confirmed test results, negative or positive, by both tests. A confirmed negative result was associated with a negative predictive value of 99.1%, providing a clear indication to exclude a diagnosis of NPC; a confirmed positive result was associated with a positive predictive value of 86.8%, providing a clear indication to proceed with diagnostic work-up of NPC. The remaining patients gave equivocal test results, being positive for one or the other test, which were associated with a positive predictive value of 43.3% and 24.2%, respectively.

Studies of neutralising antibodies to SV40 in human sera

It has been suggested that the low levels of antibody to the simian polyoma virus SV40 found in human sera may be linked to the use of polio vaccines. Panels of sera from areas of the world with different vaccination histories were examined to see if consistent differences could be identified. In a total of 2,054 sera from the United Kingdom, 692 from Africa and 923 from Poland taken between 1985 and 1997, the seroprevalence was generally between 3 and 5%, although exceptionally one collection from Morocco had a prevalence of 100%, and one from Poland of 0.4%. The seroprevalence showed no obvious age-dependent increase and titres were low compared to post infection animal sera. The results are consistent with previous studies and reveal no general geographically based differences related to possible differences in vaccination history, but the origin of the SV40 antibody in human sera remains to be established.

Circulating nucleosomes and response to chemotherapy: an in vitro, in vivo and clinical study on cervical cancer patients

It is known that cell-free DNA circulates in plasma/serum of patients with cancer and that part of this DNA circulates as nucleosomes that can be quantified by ELISA. We analyzed the effect of tumor and chemotherapy upon the levels of nucleosomes in vitro, in vivo and in cervical cancer patients. The levels of nucleosomes pre- and post-treatment were correlated with response in 11 patients receiving chemotherapy. Nucleosomes were determined in nude mice treated with or without cisplatin and carrying tumors generated with HeLa cells, and in the cell lysate and supernatant of HeLa cells exposed to cisplatin in culture. In addition, nucleosomes were determined at different time points in patients and in rats receiving chemotherapy. Nucleosomes were higher in patients that controls (1,760 vs. 601, p = 0.0001). After 24 hr of treatment with oxaliplatin and gemcitabine, the levels decreased in 6 patients of whom 5 had response. Nucleosome levels differed between mice xenografted and not xenografted (765 vs. 378, p = 0.001) and between xenografted treated with or without cisplatin (650 vs. 765, p = 0.010), but not in tumor-free animals treated and untreated with cisplatin (378 vs. 379, p = 0.99). In vitro, nucleosomes reached at peak 8 hr in cell lysates to decrease thereafter, whereas in supernatant, levels continued to increase up to 24 hr. Serial determination of nucleosomes in patients showed a rise within 6-12 hr and then a reduction to below the basal at 24 hr. In rats, nucleosomes had no major changes in those receiving oxaliplatin or the triple combination of cisplatin, gemcitabine and paclitaxel as compared to untreated controls. An overdose of this triple combination produced a transient elevation of almost 1,000 AU over the basal. Our results demonstrate that most of circulating nucleosomes originate from the tumor and that chemotherapy produces an early rise most likely due to tumor apoptosis and that nucleosomes are rapidly cleared from circulation. On the contrary, chemotherapy within the therapeutic range of doses has no effect on nucleosome levels in healthy mice and rats. This data suggests that the determination of circulating nucleosomes pre- and post-treatment could be a useful test to predict response to chemotherapy in cancer patients.

Effect of plasma micronutrients on clearance of oncogenic human papillomavirus (HPV) infection (United States)

OBJECTIVE

Data have suggested that higher levels of nutrients are protective against HPV persistence and cervical neoplasia. This study assessed the role of circulating nutrients on clearance of oncogenic HPV infections.

METHODS

Women were followed prospectively with visits at baseline and approximately 4- and 10-months post-baseline. At each visit, 15 oncogenic HPV types were determined. Plasma levels were assessed at the 4-month visit for retinol, carotenoids (i.e., alpha-, trans-beta-, cis-beta-carotene, alpha-, beta-cryptoxanthin, lutein, zeaxanthin, trans- and cis-lycopene), tocopherols (i.e., alpha-, delta-, and gamma-tocopherol), folate and vitamin B12. Using multivariate Cox proportional hazards models, time to clearance analyses of oncogenic HPV infections were conducted for 84 women with at least one oncogenic infection at baseline. Hazard ratios (HR) were estimated for the association of HPV clearance to each nutrient tertile and to determine linear trends.

RESULTS

The likelihood of clearing an oncogenic HPV infection was significantly higher with increasing levels of trans-lycopene (p for trend, 0.025) and cis-lycopene (p for trend, 0.010). The adjusted hazard ratios of the highest tertiles of trans- and cis-lycopene were 2.79 (95% CI = 1.17-6.66) and 2.92 (95% CI = 1.28-6.63) compared with the lowest tertiles.

CONCLUSIONS

Higher concentrations of trans- and cis-lycopene may reduce the time to clearance of an oncogenic HPV infection.

Content of folic acid and free homocysteine in blood serum of human papillomavirus-infected women with cervical dysplasia

The authors estimated the concentrations of folic acid and free homocysteine in the blood serum of women with CIN III (cervical intraepithelial neoplasia-Burghard's classification) infected with DNA HPV (human papillomaviruses) of type 16 and/or 18. The control group consisted of 49 patients with normal cytological smears without HPV infection. Types 16 and/or 18 DNA HPV were found in 50 patients. This women qualified for the studied group. The sequence of DNA HPV type 16 and/or 18 was identified with the PCR method (polymerase chain reaction). The high-performance liquid chromatography (HPLC) method was employed to evaluate the levels of folic acid and free homocysteine in the blood serum of the examined patients. Significantly lower levels of folic acid and higher levels of free homocysteine were observed in the blood serum of HPV-positive patients with CIN III. The correlation was found between serum concentrations of folic acid and free homocysteine in both groups.

[Oncologic risk factors in papillomavirus infection]

Cytological screening is essential for adequate diagnosis of gynecological cancer. Moreover, every effort should be made to identify such risks of cancer as viruses (HPV, Herpes simplex, cytomegalovirus, Epstein-Barr virus, etc.). When high risk HPV-16 and HPV-18 are detected, diagnostic strategies should include assay of blood prolactin and prolactin/TTH ratio. Virus-related tumors and various risk groups may be studied using HPV genotyping detection of high-risk alleles of certain genes. Hence, some HPV gene variants and gene polymorphism can be investigated as potential risk factors in women.

Codon 72 polymorphism of p53 in Israeli Jewish cervical cancer patients and healthy women

Recently it has been found that the presence of homozygous arginine polymorphism at codon 72 of p53, represents a significant risk factor in the development of HPV-associated cervical cancer. The incidence of cervical carcinoma is persistently very low in Israeli Jewish women for unknown reasons. The incidence among those of North African origin is relatively higher. The aim of the present study was to assess the frequency distribution of the p53 homozygous arginine polymorphism in cervical cancer patients and in a population sample of healthy Israeli Jewish women in order to determine whether the incidence pattern among them is genetically based. The cases consisted of 23 Israeli Jewish patients with histologically confirmed squamous cell carcinoma of the cervix. A group of 162 randomly chosen Israeli Jewish healthy participants, considered to represent the general population, comprised the controls. The germline p53 polymorphism at codon 72 was determined by PCR in DNA obtained from a blood sample taken from each subject. Homozygous arginine was found in 34.8% of cases and in only 14.8% of controls. This difference was statistically significant (P = 0.01). The frequency of homozygous arginine polymorphism in controls was lower than in any other population hitherto reported. It was significantly more common among those of North African than among those of other origin (30.3% vs. 10.8%; P < 0.01). It may be assumed that the low incidence of cervical cancer in Israeli Jewish women and the differences between the ethnic groups may be related to the frequency pattern of the homozygous arginine p53 polymorphism

Suppression of retrovirus-induced immunodeficiency disease (murine AIDS) by trimidox and didox: novel ribonucleotide reductase inhibitors with less bone marrow toxicity than hydroxyurea

Recently, the use of the ribonucleotide reductase (RR) inhibitor hydroxyurea (HU) in combination with nucleoside analogs has gained attention as a potential strategy for anti-HIV-1 therapy. However, appeal for the long-term use of HU in HIV-1 infection may be limited by its propensity to induce hematopoietic toxicity. We report a comparison of the efficacy and bone marrow toxicity of HU (400 and 200 mg/kg/day) with the novel RR inhibitors and free radical-scavenging compounds didox (DX; 3,4-dihydroxybenzohydroxamic acid; 350 mg/kg/day) and trimidox (TX; 3,4,5-trihydroxybenzamidoxime; 175 mg/kg/day) in the murine AIDS (LPBM5 MuLV) model of retrovirus infection. Infected mice received daily drug treatment for 8 weeks. Efficacy was determined by measuring drug effects on retroviral-induced disease progression (i.e. development of splenomegaly and hypergammaglobulinemia) and by evaluating splenic levels of proviral DNA. Bone marrow toxicity was evaluated by measuring peripheral blood indices (WBC, hematocrit and reticulocyte counts), femoral cellularity and by determining the numbers of hematopoietic progenitor cells (CFU-GM, BFU-E) per femur and spleen. Compared to infected controls receiving no drug treatment, disease progression was significantly suppressed by TX, DX and HU. However, HU was associated with mortality and induced significant hematopoietic toxicity in a time- and dose-dependent manner. Conversely, TX and DX effectively inhibited retrovirus-induced disease but did not induce hematopoietic toxicity. These results suggest that due to their reduced hematopoietic toxicity and ability to inhibit disease progression in murine AIDS, TX and DX may offer effective alternatives to HU therapy in HIV-1 infection.

Simultaneous measurement of several cytokines using small volumes of biospecimens

The role of host immunity in the development of virus-induced cancers has been difficult to elucidate, in part because of our inability to effectively measure multiple immune parameters using available amounts of biological material. The objective of the present study was to validate the use of a newly developed multiplex assay, the LINCOplex assay, for the simultaneous measurement of multiple cytokines [interleukin/(IL)-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IFN-gamma, and tumor necrosis factor-alpha]. Supernatants obtained from peripheral blood mononuclear cell cultures stimulated with various different mitogens and antigens (including phytohemagglutinin, influenza, tetanus, HPV16 E6 and E7 peptides, and media alone) were selected for study. In total, 750 specimens obtained from 26 participants were tested in replicate using the 8-plex LINCOplex assay (25 micro l of specimen required per well). Every specimen was included in duplicate in a blinded fashion. For some specimens, multiple 2-fold dilutions of the same specimen were included to evaluate the linearity of results. The availability of independently obtained IL-2 and IFN-gamma results from standard single cytokine (simplex) assays allowed for a direct comparison between the LINCOplex results and those obtained from the simplex assays. Spearman correlation coefficients for continuous results, and exact agreement rates and weighted kappa statistics for quartiled variables, were computed to evaluate intra- and interassay agreement. IL-4 levels were consistently below the detectable level of the assay (3 pg/ml) whereas IL-6 and IL-8 levels were consistently above the highest detectable level of the assay (10,000 pg/ml), and these three cytokines were, therefore, not evaluated further. For the remaining five cytokines, excellent intra-assay reproducibility was observed, with Spearman correlation coefficients consistently above 0.90 for all five cytokines. Exact agreement rates ranging from 77.6-90.3% and weighted kappas ranging from 0.81-0.92 were observed. Similar results were observed when analysis was restricted to supernatants obtained from cultures that had been stimulated with HPV16 peptides and when analysis was restricted to supernatants obtained from cultures containing no antigen or mitogen, suggesting that the LINCOplex assay is applicable under conditions where moderate or weak cytokine responses/levels are expected. Linearity of results was observed when dilutions of a single specimen were blindly tested, with the exception of IL-2 and IL-10, where deviations from linearity were sometimes observed. For IL-2 and IFN-gamma, where results from simplex assays were available for comparison, the LINCOplex assay and the simplex assay results agreed well. Spearman correlation coefficients were 0.86 and 0.93 for IL-2 and IFN-gamma, respectively. Exact agreement and weighted kappa values were 68.5% and 0.72 (95% confidence interval, 0.65-0.79), respectively, for IL-2 and 67.3% and 0.73 (95% confidence interval, 0.67-0.80), respectively, for IFN-gamma. These results indicate the applicability of the LINCOplex assay for the simultaneous measurement of multiple cytokines using small amounts of biological material.

An investigation of the occurrence of SV40 antibodies in South Africa

We developed an enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to simian virus 40 (SV40) in human serum. We then used the ELISA to test for anti-SV40 antibodies in healthy individuals and patients suffering from cancer and renal diseases. The aim of the study was to determine the presence of antibodies against SV40 in sera of individuals who received the South African poliovirus vaccines from 1958 to the present. Detecting such antibodies could give an indication of whether any of the poliovirus vaccines used in South Africa were ever contaminated with the SV40 or not. A total of 5/164 samples were repeatedly positive for SV40 antibodies by the ELISA. Four of the samples were from the healthy population group and the remaining 1 (1/64) was from the patient group. An SV40 antibody-blocking assay and a Western blot were used as additional confirmation for the SV40 antibodies, whereas the Western blot assay developed a single common band on all 5 samples.

Serum selenium and the risk of cervical cancer among women in the United States

OBJECTIVE

To explore the relationship between serum selenium and cervical cancer.

METHODS

We conducted a case-control study of cervical cancer in five areas around Birmingham, AL; Chicago, IL; Denver, CO; Miami, FL; and Philadelphia, PA. Community controls were selected by random-digit dialing and were matched to invasive cervical cancer cases by age, race/ethnicity, and telephone exchange. Serum selenium was determined by neutron activation analysis. Logistic regression analysis controlling for known risk factors of cervical cancer, including human papillomavirus (HPV) type-16 measured serologically, was performed on 227 invasive cases, 127 in-situ cases, and 526 controls.

RESULTS

Values of serum selenium ranged from 67.5 to 185.0 ng/ml. Adjusted odds ratios for invasive cervical cancer by quintile were: 1.0 (highest selenium), 1.1, 1.0, 0.8, and 1.0 (lowest selenium), p for trend = 0.82. Similar patterns were observed for Stage I invasive, and Stages II-IV invasive cases, suggesting severity of disease did not influence the null results. Although no associations were seen among current or never smokers, a protective effect of selenium was suggested among former smokers. Effect modification was not evident for other variables examined.

CONCLUSIONS

This study does not support a relationship between serum selenium and invasive cervical cancer at typical serum selenium levels in the US.

Human polyoma virus BK DNA detection by nested PCR in renal transplant recipients

Several studies report a correlation between the human polyomavirus BK (BKV) and interstitial nephritis in renal transplant recipients in whom immunosuppressive treatment is thought to allow or induce reactivation of the virus. Furthermore, it is described that nephropathy may result from the use of newly introduced immunosuppressive drugs. In the present study, we evaluated the presence of BKV DNA by nested-PCR (n-PCR) in urine and serum samples from 35 renal transplant patients related to the immunosuppressive regimens and renal function.

Optimization of a human papillomavirus-specific enzyme-linked immunosorbent assay

A strategy was developed for the control, standardization, and critical evaluation of an enzyme-linked immunosorbent assay (ELISA) for the detection of human papillomavirus-specific immunoglobulin G in human sera. Control human sera, polyclonal animal sera, and monoclonal antibodies were used to establish optimal assay parameters, including antigen coating, serum dilutions, and criteria for daily reproducibility, monitoring, and rejection of assays. Three evaluation techniques were used in parallel to define an optimal cutoff absorbance value that yields greater than 93% sensitivity and 98.5% specificity in the assay's ability to discriminate positive and negative control sera. This strategy provides an optimal method by which to determine cutoff absorbance values for ELISA.

Prevalence of equine herpesvirus types 2 and 5 in horse populations by using type-specific PCR assays

Equineherpesvirustypes 2 and 5 (EHV-2andEHV-5)have a rather unclearpathogenicity and distribution within the equid population. In order to gain more information on the prevalence of these two viruses, type-specific PCR assays were developed to detect viral DNA in nasal specimens and in peripheral blood leukocytes (PBLs) of adult horses and foals from various regions of Europe, i.e. Sweden, Hungary and the United Kingdom. In adult horses, the prevalence of EHV-2 in PBLs was up to 68% in Sweden and 71% in the United Kingdom. EHV-2 DNA was detected in the PBLs from all the foals tested in all countries and most (93%) of the nasal specimens also yielded positive results. The prevalence of EHV-5 DNA in the PBLs of foals in Hungary was 15 and 24% in adult horses in the United Kingdom. This observation was among the very few reports of the presence of EHV-5 in horses. In summary, the specific PCR assays revealed important data on the occurrence and distribution of EHV-2 and EHV-5 in large horse populations. The findings indicated that infection with EHV-5 occurred later than EHV-2 in foals. This study may contribute to a better understanding of the etiological role of these gammaherpesviruses in equine diseases.

Real-time quantitative analysis of polyoma BK viremia and viruria in renal allograft recipients

Polyoma BK virus (BKV) remains dormant in the urinary tract and circulating leucocytes and becomes reactivated during immunosuppression. BK viruria is prevalent in renal allograft recipients and BK viremia may be related to nephropathy and allograft rejection. How BK viruria and viremia are related in renal allograft patients is undefined. In this study, BKV copies in paired urine and serum samples of renal allograft recipients were measured by a real time quantitative polymerase chain reaction (Q-PCR) to test the hypothesis that their quantitative relationship might help to delineate viral reactivation patterns in these tissues. Urine and plasma samples from 44 renal allograft recipients with stable graft function were collected during outpatient follow-up and the genome copies of BKV were determined by Q-PCR. All patients showed quantifiable viremia and two groups of patients were identified: one group of patients (n=35) showed low viral load (median: 270/ml, range: 108-1000/ml) and the other group (n=9) with high viral load (median: 5x10(4)/ml, range: 2x10(4)-6x10(4)/ml). The corresponding median levels of viruria were 2000 and 900 ml. BK viremia and viruria were not related quantitatively. BK viremia/viruria were also not related to age, immunosuppression, time and source of renal grafts and serum creatinine levels. The absence of a quantitative relationship between BK viremia and viruria may reflect independent BKV reactivation in different tissues during immunosuppression.

Sexual behavior, human papillomavirus type 16 (HPV 16) infection, and HPV 16 seropositivity

BACKGROUND

Sexual behaviors have been linked to seropositivity for human papillomavirus (HPV) but not with the magnitude of the seroreactivity.

GOALS

The objective of this analysis was to examine the association of sexual behavior, cervical HPV 16 DNA positivity at enrollment (past) and at diagnosis (current), and other potential determinants with the likelihood and magnitude of HPV 16 seropositivity at diagnosis.

STUDY DESIGN

With use of stored specimens from an incidence case-control study at Kaiser Permanente (Portland, OR), women were tested for seroreactivity to HPV 16 by enzyme-linked immunosorbent assay with virus-like particles at diagnosis and were tested for past and concurrent cervical HPV 16 DNA positivity with MY09/MY11 L1 consensus primer PCR. Questionnaire data were used to ascertain past sexual behavior.

RESULTS

Increased lifetime number of sex partners (P(Trend) < 0.001), past HPV 16 DNA positivity (odds ratio = 6.9; 95% confidence interval = 1.5-31), and a current cytologic diagnosis (P(Trend) < 0.03) were independently associated with HPV 16 seropositivity. Among the seropositive, only lifetime number of sex partners (P(Trend) < 0.001) and past HPV 16 DNA positivity (P = 0.003) were independently associated with mean signal strength (optical density) in an age-adjusted analysis. Women negative for past and concurrent HPV 16 DNA had a significant trend of increasing optical densities associated with greater numbers of lifetime partners (P(Trend) < 0.001). Conversely, the mean signal strength for those women who were ever HPV 16 DNA-positive during the study did not depend on lifetime numbers of sex partners (P(Trend) = 0.36).

CONCLUSIONS

HPV 16 seropositivity is a surrogate for past HPV 16 infection. Circulating levels of antibodies to HPV 16 may reflect recent HPV 16 infection or the frequency of past HPV 16 infection.

A population-based study of squamous cell vaginal cancer: HPV and cofactors

BACKGROUND

Little is known about the etiology of in situ or invasive squamous cell cancer of the vagina. It is thought that some vaginal cancers may have the same etiology as cervical cancer. It is also not known whether in situ and invasive vaginal cancer share the same etiologic factors. We conducted a study to evaluate risk factors for in situ and invasive vaginal cancer and their potential relationship to prior exposure to human papillomaviruses (HPV).

METHODS

A population-based case-control study included 156 women with squamous cell in situ or invasive vaginal cancer diagnosed between January 1981 and June 1998 and 2041 control women identified through random-digit dialing in western Washington state. Cases and controls were interviewed in person and provided blood samples; archival tumor tissue was retrieved for cases. Blood samples were tested for antibodies to HPV, and tumor tissue was tested for HPV DNA.

RESULTS

Women with vaginal cancer were more likely to have five or more lifetime sexual partners (OR = 3.1, 95% CI 1.9 to 4.9), to have an early age at first intercourse (<17 years OR = 2.0, 95% CI 1.2 to 3.5), and to be current smokers at diagnosis (OR = 2.1, 95% CI 1.4 to 3.1) than control women. Approximately 30% of all cases had been treated for a prior anogenital tumor, most often of the cervix. Prior hysterectomy was a risk factor only among women who had no history of prior anogenital cancer (OR = 3.9 95% CI 2.5 to 6.1). Antibodies to HPV16 L1 were strongly related to risk of vaginal cancer (OR = 4.3, 95% CI 3.0 to 6.2). We detected HPV DNA in tumor blocks from over 80% of the patients with in situ and 60% of the patients with invasive cancers.

CONCLUSIONS

In situ and invasive vaginal neoplasia have many of the same risk factors as cervical cancer, including a strong relationship to HPV infection. Women who have been treated for a prior anogenital cancer, particularly of the cervix, have a high relative risk, although low absolute risk, of being diagnosed with vaginal cancer.

Serum micronutrients and cervical dysplasia in Southwestern American Indian women

We carried out a clinic-based case-control study to assess serum micronutrients as risk factors for cervical dysplasia among Southwestern American Indian women, a group with high rates of cervical preinvasive lesions. Cases were American Indian women with biopsy-proven cervical intraepithelial neoplasia (CIN I or CIN II/III). Controls were from the same Indian Health Service clinics with normal cervical epithelium. We interviewed women about histories of sexually transmitted diseases, sexual behavior, diet, hygienic practices, cigarette smoking, and reproductive factors. Laboratory assays included serum for retinol (vitamin A), ascorbic acid (vitamin C), alpha-tocopherol (vitamin E), and red blood cell folate levels, DNA for human papillomavirus (HPV) typing, and tests for other sexually transmitted diseases. The strongest risks for cervical dysplasia were associated with cervical HPV infection [odds ratio (OR) = 3.2, 95% confidence interval (CI) = 2.2-4.6 and OR = 7.9, 95% CI = 4.8-13.1 for CIN I and CIN II/III, respectively]. With adjustments made for HPV infection and other relevant confounders, subjects in the lowest serum retinol quartile were at increased risk of CIN I compared with women in the highest quartile (OR = 2.3, 95% CI = 1.3-4.1). The data suggest that low serum alpha-tocopherol was associated with CIN I/III, although the adjusted OR was not statistically significant (OR = 2.0, 95% CI = 0.9-4.8). Low serum ascorbic acid and red blood cell folate were not associated with cervical dysplasia.

Identification of peptide sequences specific for serum antibodies from human papillomavirus-infected patients using phage display libraries

Three random phage display peptide libraries were screened with sera from human papillomavirus (HPV)-infected patients to characterize the specificities of antibodies present in patients' sera and to identify molecules that correspond to or mimic natural epitopes; 141 phage clones were randomly selected in three rounds of bioselection and their binding properties were analyzed in ELISA using sera from 36 patients with confirmed HPV 16 infection and 24 healthy control female blood donors. Sixteen of 36 (44%) patients' sera reacted with at least 1 phage clone, and only 2 of 24 female donors' sera showed positive reaction with 1 of the selected clones. We conclude that the combination of various disease-specific epitopes generated by screening of phage display peptide libraries may potentially lead to a multicomponent diagnostic assay for the early detection of HPV infection and precancerous cervical lesions, making possible the prevention of one of the most common cancers in women.