Prediagnostic Circulating Antibodies to JC and BK Human Polyomaviruses and Risk of Non-Hodgkin Lymphoma

Use of dipyridamole is associated with lower risk of lymphoid neoplasms: a propensity score-matched cohort study

The anti-cancer potential of dipyridamole has been suggested from experiments, but evidence from population-based studies is still lacking. We aimed to explore if dipyridamole use was related to a lower risk of lymphoid neoplasms. We identified individuals with prescription of aspirin after diagnosis of ischaemic cerebrovascular disease since 2006 by linking several Swedish registers. In these aspirin users, those with dipyridamole prescription were further identified as the study group and patients without dipyridamole were randomly selected as reference group with 1:1 ratio using a propensity score-matching approach. After a median of 6·67 years of follow-up, a total of 46 patients with dipyridamole use developed lymphoid neoplasms with an incidence rate of 0·49 per 1 000 person-years, while the rate in the matched group was 0·74 per 1 000 person-years. As compared to non-users, dipyridamole users were associated with a significantly decreased risk of lymphoid neoplasms [hazard ratio (HR) = 0·65; 95% confidence interval (CI) = 0·43-0·98]. Specifically, the reduced risk was observed for non-Hodgkin lymphomas (HR = 0·64; 95% CI = 0·42-0·94), especially B-cell lymphomas (HR = 0·56; 95% CI = 0·35-0·88). Dipyridamole use was related to a lower risk of lymphoid neoplasms, indicating a clinical potential of dipyridamole to be an adjunct anti-tumour agent against lymphoid neoplasms.

Associations of Viral Seroreactivity with AIDS-Related Non-Hodgkin Lymphoma

Infection with human immunodeficiency virus (HIV) is associated with substantially increased incidence of non-Hodgkin lymphoma (NHL). This risk may be driven, in part, by reduced immune control over viral infections in the setting of acquired immunodeficiency syndrome (AIDS), although the lymphomagenic mechanisms are not yet established. We used bead-based multiplex assays to measure antibody seroreactivity to 32 viral antigens representing 22 different viral infections (human herpesviruses 1-8, hepatitis B and C virus, human T-lymphotropic virus type-1, and human polyomaviruses) in two prospective HIV cohorts. Incident (n = 28) and prevalent (n = 38) AIDS-related NHL cases were matched by age, sex, race, and CD4 count to 67 HIV-positive control individuals without AIDS-NHL. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for associations of AIDS-NHL with the number of different viruses to which an individual was seropositive and seroreactivity to individual antigens. Seropositivity to an increasing number of viruses was inversely associated with AIDS-NHL (OR per virus = 0.84, 95% CI = 0.72-0.98). Seroreactivity to herpes simplex virus 2 2mgG unique antigen (OR = 0.47; 95% CI = 0.23-0.97) and to WU polyomavirus viral capsid protein (OR = 0.26, 95% CI = 0.10-0.65) was significantly lower in AIDS-NHL cases compared to controls. In this evaluation of antibodies to multiple viruses, we observed an inverse association between seropositivity to a larger number of viruses and AIDS-NHL. While in need of further evaluation, our data raise the novel hypothesis that insufficient exposures or impaired humoral immune responses to viral infections may be associated with AIDS-related lymphomagenesis.

Human BK and JC polyomaviruses: Molecular insights and prevalence in Asia

Polyomaviridae family consists of small circular dsDNA viruses. Out of the 14 human polyomaviruses described so far, BKPyV and JCPyV have been studied extensively since their discovery in 1971. Reportedly, both BKPyV and JCPyV are widely distributed across the globe with the frequency of 80-90 % in different populations. The primary infection of these viruses is usually asymptomatic and latent which is activated as a consequence of immunosuppression. Activated BKPyV and JCPyV viruses lead to the development of BK Virus Associated Nephropathy and Progressive Multifocal Leukoencephalopathy, respectively. Immense progress has been made during the last few decades regarding the molecular understanding of polyomaviruses. Epidemiology of polyomaviruses has also been studied extensively. However, most of the epidemiological studies have focused on European and American populations. Therefore, limited data is available regarding the geographical distribution of these potentially oncogenic viruses in Asian countries. In this article, we have presented a compendium of latest advances in the molecular understanding of polyomaviruses and their pathobiology. We also present a comprehensive review of published literature regarding the epidemiology and prevalence of BKPyV and JCPyV in Asian regions. For this purpose, a thorough search of available online resources was performed. As a result, we retrieved 24 studies for BKPyV and 22 studies for JCPyV, that describe their prevalence in Asia. These studies unanimously report high occurrence of both BKPyV and JCPyV in Asian populations. The available data from these studies was categorized into two groups: on the basis of prevalence (low, medium and high) and disease development (healthy and diseased). Altogether, Korean population hasbeen evidenced to possess highest frequency of BKPyV (66.7 %), while JCPyV was found to be most prevalent in Taiwan (88 %). Due to high and ubiquitous distribution of these viruses, frequent studies are required to develop a better understanding regarding the epidemiology and pathobiology of these viruses in Asia.

Human polyomaviruses and cancer: an overview

The name of the family Polyomaviridae, derives from the early observation that cells infected with murine polyomavirus induced multiple (poly) tumors (omas) in immunocompromised mice. Subsequent studies showed that many members of this family exhibit the capacity of mediating cell transformation and tumorigenesis in different experimental models. The transformation process mediated by these viruses is driven by viral pleiotropic regulatory proteins called T (tumor) antigens. Similar to other viral oncoproteins T antigens target cellular regulatory factors to favor cell proliferation, immune evasion and downregulation of apoptosis. The first two human polyomaviruses were isolated over 45 years ago. However, recent advances in the DNA sequencing technologies led to the rapid identification of additional twelve new polyomaviruses in different human samples. Many of these viruses establish chronic infections and have been associated with conditions in immunosuppressed individuals, particularly in organ transplant recipients. This has been associated to viral reactivation due to the immunosuppressant therapy applied to these patients. Four polyomaviruses namely, Merkel cell polyomavirus (MCPyV), Trichodysplasia spinulosa polyomavirus (TSPyV), John Cunningham Polyomavirus (JCPyV) and BK polyomavirus (BKPyV) have been associated with the development of specific malignant tumors. However, present evidence only supports the role of MCPyV as a carcinogen to humans. In the present review we present a summarized discussion on the current knowledge concerning the role of MCPyV, TSPyV, JCPyV and BKPyV in human cancers.

Serologic markers of viral infection and risk of non-Hodgkin lymphoma: A pooled study of three prospective cohorts in China and Singapore

Incidence rates of non-Hodgkin lymphoma (NHL) and distributions of certain viruses differ between East Asian and Western populations. There are limited data on associations between serologic markers of multiple viral infections in pre-diagnostic blood and NHL risk in East Asians. We conducted a nested case-control study of 214 NHL cases and 214 matched controls from three population-based prospective cohorts in Shanghai and Singapore. Antibodies against antigens from herpesviruses, Hepatitis B (HBV) and C (HCV) virus and polyomaviruses were measured in plasma or serum using fluorescent bead-based multiplex assays. Conditional logistic regression was used to evaluate associations between antibody levels and NHL risk. An increased risk of NHL was observed for higher compared to lower EA-D (Odds Ratio (OR) = 2.04, 95% Confidence Interval (CI) = 1.10-3.81; ptrend  = 0.005) and ZEBRA (OR = 2.17, 95% CI = 0.96-4.89; ptrend  = 0.008) Epstein-Barr Virus (EBV) antibodies, as well as for antibody seropositivity against the IE1A human herpesvirus-6 (HHV-6) antigen (OR = 1.85, 95% CI = 1.04-3.29). An increased NHL risk was also observed for higher compared to lower antibodies against the HBV-HBc and HBe antigens. An increased risk of NHL in relation to EBV and HBV infection in East Asians is consistent with findings in several studies of Western populations, suggesting similar viral risk factors for NHL in these diverse populations with distinct patterns of NHL. The association between HHV-6 antibodies and NHL has not previously been reported in a prospective study in this population and will require replication.

Prospective Study of Human Polyomaviruses and Risk of Cutaneous Squamous Cell Carcinoma in the United States

BACKGROUND

Merkel cell polyomavirus (PyV) is causally related to Merkel cell carcinoma, a rare skin malignancy. Little is known about the serostability of other PyVs over time or associations with cutaneous squamous cell carcinoma (SCC).

METHODS

As part of a U.S. nested case-control study, antibody response against the PyV VP1 capsid proteins of BK and John Cunningham virus (JC) was measured using multiplex serology on 113 SCC cases and 229 gender, age, and study center-matched controls who had a prior keratinocyte cancer. Repeated serum samples from controls and both pre and postdiagnosis samples from a subset of SCC cases were also tested. Odds ratios (OR) for SCC associated with seropositivity to each PyV type were estimated using conditional logistic regression.

RESULTS

Among controls, BK and JC seroreactivity was stable over time, with intraclass correlation coefficients of 0.86 for BK and 0.94 for JC. Among cases, there was little evidence of seroconversion following SCC diagnosis. JC seropositivity prior to diagnosis was associated with an elevated risk of SCC (OR = 2.54; 95% CI, 1.23-5.25), and SCC risk increased with increasing quartiles of JC (Ptrend = 0.004) and BK (Ptrend = 0.02) seroreactivity.

CONCLUSIONS

PyV antibody levels were stable over time and following an SCC diagnosis. A history of PyV infection may be involved in the occurrence of SCC in a population at high risk for this malignancy.

IMPACT

A single measure of PyV seroreactivity appears a reliable indicator of long-term antibody status, and PyV exposure may be a risk factor for subsequent SCC. Cancer Epidemiol Biomarkers Prev; 25(5); 736-44. ©2016 AACR.

JC virus antibody index in natalizumab-treated patients: correlations with John Cunningham virus DNA and C-reactive protein level

Natalizumab-treated patients have a higher risk of developing progressive multifocal leukoencephalopathy. Exposure to John Cunningham virus (JCV) is a prerequisite for PML (progressive multifocal leukoencephalopathy). To assess JCV exposure in multiple sclerosis patients, we performed a serological examination, obtained the antibody index, performed real-time polymerase chain reaction (PCR) to detect JCV DNA in plasma and urine, and investigated the role of ultrasensitive C-reactive protein (usCRP) as a possible biological marker of JCV reactivation. We retrospectively analyzed consecutive natalizumab-treated multiple sclerosis patients who underwent a JCV antibody test through a two-step enzyme-linked immunosorbent assay (STRATIFY test) to the measure of serum usCRP levels, and to perform blood and urine JCV PCR. The studied cohort included 97 relapsing–remitting patients (60 women). Fifty-two patients (53.6%) tested positive for anti-JCV antibodies. PCR showed JCV DNA in the urine of 30 out of 83 (36.1%) patients and 28 out of 44 seropositive patients (63.6%), with a 6.7% false-negative rate for the STRATIFY test. Normalized optical density values were higher in urinary JCV DNA-positive patients (P<0.0001). Interestingly, the level of usCRP was higher in urinary JCV DNA-positive patients and correlated to the number of DNA copies in urine (P=0.028). As expected, patients’ age correlated with JCV seropositivity and with JC viruria (P=0.02 and P=0.001, respectively). JC viruria was significantly correlated with a high JCV antibody index and high serum usCRP levels. We suggest that PCR and usCRP might be useful as markers of JCV reactivation, and that patients should be monitored between STRATIFY assessments.

Prospective study of seroreactivity to JC virus T-antigen and risk of colorectal cancers and adenomas

John Cunningham virus (JCV) is a common polyomavirus classified as a possible carcinogen by the International Agency for Research on Cancer. JCV may play a role in colorectal carcinogenesis, although we previously reported no association between JCV capsid antibodies and colorectal cancer. No studies have examined the role of seroreactivity to JCV T-antigen (T-Ag) oncoprotein in colorectal cancer. A case-control study nested within a community-based prospective cohort (CLUE II) was conducted. In 1989, 25,080 residents of Washington County, Maryland, were enrolled in CLUE II, completing baseline questionnaires and providing blood samples. At follow-up, 257 incident colorectal cancer cases were identified by linkage to population-based cancer registries through 2006 and matched to controls on age, sex, race, and date of blood draw. One hundred and twenty-three colorectal adenoma cases were identified through self-report during follow-up and matched to controls on age, sex, race, date of blood draw, and colorectal cancer screening. Baseline serum samples were tested for seroreactivity to JCV T-Ag. Associations between JCV T-Ag seroreactivity and colorectal cancer/adenomas were evaluated using conditional logistic regression models. Overall, seroreactivity to JCV T-Ag was not statistically significantly associated with the risk of either colorectal cancer [OR, 1.34; 95% confidence interval (CI), 0.89-2.01] or adenoma (OR, 1.30; 95% CI, 0.70-2.42), while a borderline association with colorectal cancer was observed among women (OR, 1.82; 95% CI, 1.00-3.31). Our past evaluation of JCV capsid seropositivity, combined with current findings, does not support a notable etiologic role for JCV infection in colorectal cancer.

Epstein-Barr virus and risk of non-Hodgkin lymphoma in the cancer prevention study-II and a meta-analysis of serologic studies

Epstein-Barr virus (EBV) causes rare, malignant lymphomas. The role of EBV in other non-Hodgkin lymphomas (NHLs) remains unclear, but mildly reduced immune function could lead to reactivation of EBV and subsequent NHL. We examined the association between prospectively-collected plasma EBV antibodies and NHL risk in the Cancer Prevention Study-II (CPS-II) Nutrition Cohort and conducted a meta-analysis of our and published results. The CPS-II study included 225 NHL cases and 2:1 matched controls. No associations were observed between EBV serostatus or antibody levels and risk of NHL overall. However, when including only the three most common types of NHL (diffuse large B-cell lymphoma, follicular lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma), high compared to low early antigen (EA-D) diffuse and BZLF1-encoded replication activator antibodies were associated with approximately 60% higher risk of NHL. Odds ratios (ORs) for EBV nuclear antigen-1 and viral capsid antigen (VCA)-p18 were elevated but not statistically significant. In the meta-analysis, both EA (summary OR = 1.52, 95% confidence interval (CI): 1.16-2.00) and VCA (summary OR = 1.20, 95% CI: 1.00-1.44) were positively associated with NHL risk. These results suggest EBV may be associated with a wider spectrum of NHL subtypes, but further study is needed to confirm and fully understand these associations.

JCV epidemiology in MS (JEMS)--epidemiology of anti-JCV antibody prevalence in multiple sclerosis patients--Portuguese data

BACKGROUND

Progressive multifocal leukoencephalopathy, caused by oligodendrocyte lytic infection by JCVirus, is a growing concern for patients undergoing immune modulatory therapies for treatment of autoimmune diseases, such as multiple sclerosis (MS). The objective of JEMS was to describe the prevalence of anti-JCV antibodies in MS patients and to assess the various factors associated to it.

METHODS

Serum samples were collected and tested for anti-JCV antibody using the STRATIFY JCV™ assay in 131 Portuguese MS patients. Factors potentially associated with prevalence were also evaluated, as well as the effect of established risk factors.

RESULTS

In the population of 131 Portuguese patients included in the JEMS, the overall anti-JCV antibody prevalence was 69.5% (95% CI, 61.6-77.4). The anti-JCV antibody prevalence did not seem to be influenced by demographic characteristics, although results demonstrate a non-significant trend for increased prevalence with age. Disease characteristics, treatment duration, treatment history, prior immunosuppressive therapy use and natalizumab exposure duration did not seem to be associated with anti-JCV prevalence.

CONCLUSION

The results of Portuguese MS patients participating in the JEMS study present some differences when compared with the global population and literature results. An overall prevalence higher than expected raises awareness for data confirmation with greater sample size studies.

The human JC polyomavirus (JCPyV): virological background and clinical implications

JC polyomavirus (JCPyV) was the first of now 12 PyVs detected in humans, when in 1964, PyV particles were revealed by electron microscopy in progressive multifocal leukoencephalopathy (PML) tissues. JCPyV infection is common in 35-70% of the general population, and the virus thereafter persists in the renourinary tract. One third of healthy adults asymptomatically shed JCPyV at approximately 50,000 copies/mL urine. PML is rare having an incidence of <0.3 per 100,000 person years in the general population. This increased to 2.4 per 1000 person years in HIV-AIDS patients without combination antiretroviral therapy (cART). Recently, PML emerged in multiple sclerosis patients treated with natalizumab to 2.13 cases per 1000 patients. Natalizumab blocks α4-integrin-dependent lymphocyte homing to the brain suggesting that not the overall cellular immunodeficiency but local failure of brain immune surveillance is a pivotal factor for PML. Recovering JCPyV-specific immune control, e.g., by starting cART or discontinuing natalizumab, significantly improves PML survival, but is challenged by the immune reconstitution inflammatory syndrome. Important steps of PML pathogenesis are undefined, and antiviral therapies are lacking. New clues might come from molecular and functional profiling of JCPyV and PML pathology and comparison with other replicative pathologies such as granule cell neuronopathy and (meningo-)encephalitis, and non-replicative JCPyV pathology possibly contributing to some malignancies. Given the increasing number of immunologically vulnerable patients, a critical reappraisal of JCPyV infection, replication and disease seems warranted.

Anti-John Cunnigham virus antibody prevalence in multiple sclerosis patients: baseline results of STRATIFY-1

OBJECTIVE

A study was undertaken to define the prevalence of anti-JC virus (JCV) antibodies in multiple sclerosis (MS) patients and to evaluate the analytical false-negative rate of a 2-step anti-JC virus antibody assay.

METHODS

STRATIFY-1 is an ongoing, longitudinal, observational study of relapsing MS patients in the United States who are being treated or considering treatment with natalizumab. Baseline serum and plasma samples were collected for anti-JC virus antibody detection using an analytically validated, 2-step, virus-like particle-based enzyme-linked immunosorbent assay. Urine was collected for JC virus DNA detection.

RESULTS

At baseline (n = 1,096), overall anti-JC virus antibody prevalence was 56.0% (95% confidence interval [CI], 53.0-59.0) in STRATIFY-1 patients, with an assay false-negative rate of 2.7% (95% CI, 0.9-6.2). Prevalence was significantly lower in females (53.4%; 95% CI, 49.9-56.8) than males (64.3%; 95% CI, 58.2-70.0) and increased with age, p = 0.0019 and p = 0.0001, respectively. Prevalence was similar in patients regardless of natalizumab exposure or prior immunosuppressant use, p = 0.9709 and p = 0.6632, respectively. STRATIFY-1 results were generally consistent with those observed in another large North American cohort, TYGRIS-US (n = 1,480).

INTERPRETATION

Baseline results from STRATIFY-1 are consistent with other studies utilizing this assay that demonstrate a 50 to 60% prevalence of anti-JC virus antibodies, a low false-negative rate, and an association of increasing age and male gender with increasing anti-JC virus antibody prevalence. Neither natalizumab exposure nor prior immunosuppressant use appear to affect prevalence. Longitudinal data from STRATIFY-1 will confirm the stability of anti-JC virus antibody prevalence over time.

Polyoma virus-associated progressive multifocal leukoencephalopathy after renal transplantation: regression following withdrawal of mycophenolate mofetil

The 2008-released FDA safety report described a potential association between use of MMF and progressive multifocal leukoencephalopathy. We here report the case of an 11-yr-old kidney transplanted boy suffering from PML who showed rapid improvement parallel to withdrawal of MMF. This case contributes to the increasing knowledge on side effects of MMF treatment in children.

Anti-JC virus antibodies: implications for PML risk stratification

OBJECTIVE

A study was undertaken to establish an enzyme-linked immunosorbent assay (ELISA) to detect JC virus (JCV)-specific antibodies in multiple sclerosis (MS) patients, and to evaluate its potential utility for identifying patients at higher or lower risk (ie, risk stratification) of developing progressive multifocal leukoencephalopathy (PML).

METHODS

A 2-step assay for detecting and confirming the presence of anti-JCV antibodies in human serum and plasma was developed and demonstrated to be both sensitive and specific. ELISA cutpoints were statistically established using sera from >800 MS patients from natalizumab clinical studies. Subsequently, this assay was used to determine the presence of anti-JCV antibodies in natalizumab-treated PML patients where serum samples were collected 16-180 months prior to the diagnosis of PML.

RESULTS

In our evaluation of natalizumab-treated MS patients, 53.6% tested positive for anti-JCV antibodies, with a 95% confidence interval of 49.9 to 57.3%. The false-negative rate of the ELISA was calculated to be approximately 2.5%, with an upper 1-sided confidence limit of 4.4%. Notably, we observed anti-JCV antibodies in all 17 available pre-PML sera samples, which was significantly different from the 53.6% seropositivity observed in the overall MS study population (p < 0.0001).

INTERPRETATION

This 2-step assay provides a means to classify MS patients as having detectable or not detectable levels of anti-JCV antibodies. The finding that all 17 of the pre-PML samples that were available tested seropositive, and none tested seronegative, warrants further research on the clinical utility of the anti-JCV antibody assay as a potential tool for stratifying MS patients for higher or lower risk of developing PML.

Characterization of JC human polyomavirus infection in a Portuguese population

JC virus (JCV) is ubiquitous in the human population, infecting children asymptomatically. After primary infection, JCV persists in the host throughout life and is often excreted in the urine. Two hundred thirty-four urine samples and 78 serum samples, collected from 171 healthy individuals and 63 patients infected with HIV, were used to characterize JCV infection in a Portuguese population. Using PCR, JCV DNA was detected in 38% of the urine samples. A significant difference in the excretion rate was observed between patients infected with HIV (51%) and healthy individuals (33%). The frequency of JCV viruria increased with age in healthy individuals, but not in patients infected with HIV. JCV urinary load was determined by real-time quantitative PCR and was independent of gender, age, HIV infection, and CD4+ cell count. Overall, the JCV genotype detected most commonly was 1B, followed by genotypes 2B and 4. The detection and quantitation of JCV-specific antibodies were performed in serum samples by an established enzyme immunoassay (EIA). Antibodies to JCV were observed in 91% of the patients tested, irrespective of HIV infection. A positive correlation between JCV urinary load and antibody titers was demonstrated. The present study provides the first characterization of seroprevalence and urinary excretion of JCV in a Portuguese population and revealed similar results to those observed in other European countries. A comparison between healthy individuals and patients infected with HIV, despite identical values of seroprevalence, showed some differences in the pattern of urinary excretion. J. Med. Virol. 82:494-504, 2010. (c) 2010 Wiley-Liss, Inc.

Asymptomatic reactivation of JC virus in patients treated with natalizumab

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) occurs in a fraction of patients with multiple sclerosis who were treated with natalizumab. Most adults who are infected with the JC virus, the etiologic agent in PML, do not have symptoms. We sought to determine whether exposure to natalizumab causes subclinical reactivation and neurotropic transformation of JC virus.

METHODS

We followed 19 consecutive patients with multiple sclerosis who were treated with natalizumab over an 18-month period, performing quantitative polymerase-chain-reaction assays in blood and urine for JC virus reactivation; BK virus, a JC virus-related polyomavirus, was used as a control. We determined JC virus-specific T-cell responses by means of an enzyme-linked immunospot assay and antibody responses by means of an enzyme-linked immunosorbent assay and analyzed JC virus regulatory-region sequences.

RESULTS

After 12 months of natalizumab therapy, the prevalence of JC virus in the urine of the 19 patients increased from a baseline value of 19% to 63% (P=0.02). After 18 months of treatment, JC virus was detectable in 3 of 15 available plasma samples (20%) and in 9 of 15 available samples of peripheral-blood mononuclear cells (60%) (P=0.02). JC virus regulatory-region sequences in blood samples and in most of the urine samples were similar to those usually found in PML. Conversely, BK virus remained stable in urine and was undetectable in blood. The JC virus-specific cellular immune response dropped significantly between 6 and 12 months of treatment, and variations in the cellular immune response over time tended to be greater in patients in whom JC viremia developed. None of the patients had clinical or radiologic signs of PML.

CONCLUSIONS

Subclinical reactivation of JC virus occurs frequently in natalizumab-treated patients with multiple sclerosis. Viral shedding is associated with a transient drop in the JC virus-specific cellular immune response.

Molecular pathogenesis of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a highly aggressive neuroendocrine skin cancer which is twice as lethal as melanoma as more than one-third of MCC patients will die from this cancer. Although MCC, which primarily affects elderly and immune suppressed individuals, is very rare to date, its incidence is rapidly increasing. In contrast to the immense progress that has been made in the elucidation of the molecular pathogenesis of other cancer entities, until recently there were no clear-cut indications which events drive the carcinogenesis of MCC. Important findings published last year have changed this radically. Hypermethylation of the p14(ARF) promoter and a striking correlation between expression of p63 and the clinical course of MCC have been reported. Most important, however, is the discovery that MCC development in the majority of cases is preceded by the integration of genomic sequences of the hitherto unknown Merkel cell polyomavirus (MCPyV). Now a fundamental improvement in the understanding of MCC pathogenesis as well as the development of new therapeutic approaches based on this knowledge appear to be possible within the near future.

Investigation of pre-diagnostic virological markers for progressive multifocal leukoencephalopathy in human immunodeficiency virus-infected patients

Progressive multifocal leukoencephalopathy (PML) is a severe neurological disorder due to JC virus (JCV) infection. Pre-diagnostic biological markers and risk factors for PML are not well understood. We conducted a case-control study nested within the Multicenter AIDS Cohort Study to examine the association between JCV viruria and viremia and serum antibody to JCV capsids, in relation to subsequent PML diagnoses, 5 months to 12 years later. Other demographic and immunologic factors were also examined. The study population included 28 incident cases of PML, 26 matched HIV-positive controls, and 50 HIV-negative controls. Prevalence of JCV viruria was 37% in cases, 42% in HIV-positive controls, and 28% in HIV-negative controls (P = 0.43). Among persons with JCV viruria, persistent viruria was more common in cases (89%) than in HIV-positive controls (33%) (P = 0.02). Presence of JCV viruria was not related to the time to PML diagnosis (OR: 1.03, 95% CI: 0.8-1.4); however, the urinary concentration of JCV DNA increased with proximity to the date of PML diagnosis in cases. JCV seropositivity did not differ between cases or controls (P = 0.42). Four cases tested JCV seronegative, including one case only 5 months prior to diagnosis with PML. JCV DNA was detected in the serum of one HIV-positive control. Smoking was the only demographic variable analyzed associated with an increased risk for PML (MOR: 9.0, 95% CI: 1.2-394.5). The results suggest that persistent JCV viruria and increasing urinary concentration of JCV DNA may be predictive of PML for some patients.

Oral maxillofacial neoplasms in an East African population a 10 year retrospective study of 1863 cases using histopathological reports

BACKGROUND

Neoplasms of the oral maxillofacial area are an interesting entity characterized by differences in nomenclature and classification at different centers.We report neoplastic histopathological diagnoses seen at the departments of oral maxillofacial surgery of Muhimbili and Mulago referral hospitals in Tanzania and Uganda respectively over a 10-year period.

METHODS

We retrieved histopathological reports archived at the departments of oral maxillofacial surgery of Muhimbili and Mulago referral hospitals in Tanzania and Uganda respectively over a 10-year period from June 1989-July 1999.

RESULTS

In the period between June 1989 and July 1999, 565 and 1298 neoplastic oro-facial cases were retrieved of which 284 (50.53%) and 967 (74.54%) were malignant neoplasms at Muhimbili and Mulago hospitals respectively. Overall 67.28% of the diagnoses recorded were malignant with Kaposi's sarcoma (21.98%), Burkiits lymphoma (20.45%), and squamous cell carcinoma (15.22%) dominating that group while ameloblastoma (9.23%), fibromas (7.3%) and pleomorphic adenoma (4.95%) dominated the benign group.The high frequency of malignancies could be due to inclusion criteria and the clinical practice of selective histopathology investigation. However, it may also be due to higher chances of referrals in case of malignancies.

CONCLUSION

There is need to reexamine the slides in these two centers in order to bring them in line with the most recent WHO classification so as to allow for comparison with reports from else where.

Characterization of highly frequent epitope-specific CD45RA+/CCR7+/- T lymphocyte responses against p53-binding domains of the human polyomavirus BK large tumor antigen in HLA-A*0201+ BKV-seropositive donors

Human polyomavirus BK (BKV) has been implicated in oncogenic transformation. Its ability to replicate is determined by the binding of its large tumor antigen (LTag) to products of tumor-suppressor genes regulating cell cycle, as specifically p53. We investigated CD8+ T immune responses to BKV LTag portions involved in p53 binding in HLA-A*0201+ BKV LTag experienced individuals. Peptides selected from either p53-binding region (LTag351-450 and LTag533-626) by current algorithms and capacity to bind HLA-A*0201 molecule were used to stimulate CD8+ T responses, as assessed by IFN-gamma gene expression ex vivo and detected by cytotoxicity assays following in vitro culture. We observed epitope-specific immune responses in all HLA-A*0201+ BKV LTag experienced individuals tested. At least one epitope, LTag579-587; LLLIWFRPV, was naturally processed in non professional antigen presenting cells and induced cytotoxic responses with CTL precursor frequencies in the order of 1/20'000. Antigen specific CD8+ T cells were only detectable in the CD45RA+ subset, in both CCR7+ and CCR7- subpopulations. These data indicate that widespread cellular immune responses against epitopes within BKV LTag-p53 binding regions exist and question their roles in immunosurveillance against tumors possibly associated with BKV infection.