An interferon-free antiviral regimen for HCV after liver transplantation.

BACKGROUND: Hepatitis C virus (HCV) infection is the leading indication for liver transplantation worldwide, and interferon-containing regimens are associated with low response rates owing to treatment-limiting toxic effects in immunosuppressed liver-transplant recipients. We evaluated the interferon-free regimen of the NS5A inhibitor ombitasvir coformulated with the ritonavir-boosted protease inhibitor ABT-450 (ABT-450/r), the nonnucleoside NS5B polymerase inhibitor dasabuvir, and ribavirin in liver-transplant recipients with recurrent HCV genotype 1 infection. METHODS: We enrolled 34 liver-transplant recipients with no fibrosis or mild fibrosis, who received ombitasvir-ABT-450/r (at a once-daily dose of 25 mg of ombitasvir, 150 mg of ABT-450, and 100 mg of ritonavir), dasabuvir (250 mg twice daily), and ribavirin for 24 weeks. Selection of the initial ribavirin dose and subsequent dose modifications for anemia were at the investigator's discretion. The primary efficacy end point was a sustained virologic response 12 weeks after the end of treatment. RESULTS: Of the 34 study participants, 33 had a sustained virologic response at post-treatment weeks 12 and 24, for a rate of 97% (95% confidence interval, 85 to 100). The most common adverse events were fatigue, headache, and cough. Five patients (15%) required erythropoietin; no patient required blood transfusion. One patient discontinued the study drugs owing to adverse events after week 18 but had a sustained virologic response. Blood levels of calcineurin inhibitors were monitored, and dosages were modified to maintain therapeutic levels; no episode of graft rejection was observed during the study. CONCLUSIONS: Treatment with the multitargeted regimen of ombitasvir-ABT-450/r and dasabuvir with ribavirin was associated with a low rate of serious adverse events and a high rate of sustained virologic response among liver-transplant recipients with recurrent HCV genotype 1 infection, a historically difficult-to-treat population. (Funded by AbbVie; CORAL-I ClinicalTrials.gov number, NCT01782495.).

Ombitasvir plus paritaprevir plus ritonavir with or without ribavirin in treatment-naive and treatment-experienced patients with genotype 4 chronic hepatitis C virus infection (PEARL-I): a randomised, open-label trial.

BACKGROUND: Hepatitis C virus (HCV) genotype 4 accounts for about 13% of global HCV infections. Because interferon-containing treatments for genotype 4 infection have low efficacy and poor tolerability, an unmet need exists for effective all-oral regimens. We examined the efficacy and safety of an all-oral interferon-free regimen of ombitasvir, an NS5A inhibitor, and paritaprevir (ABT-450), an NS3/4A protease inhibitor dosed with ritonavir (ombitasvir plus paritaprevir plus ritonavir), given with or without ribavirin. METHODS: In this multicentre ongoing phase 2b, randomised, open-label combination trial (PEARL-I), patients were recruited from academic, public, and private hospitals and clinics in France, Hungary, Italy, Poland, Romania, Spain, Turkey, and the USA. Eligible participants were aged 18-70 years with non-cirrhotic, chronic HCV genotype 4 infection (documented ≥6 months before screening) and plasma HCV RNA levels higher than 10,000 IU/mL. Previously untreated (treatment-naive) patients were randomly assigned (1:1) by computer-generated randomisation lists to receive once-daily ombitasvir (25 mg) plus paritaprevir (150 mg) plus ritonavir (100 mg) with or without weight-based ribavirin for 12 weeks. Previously treated (treatment-experienced) patients who had received pegylated interferon plus ribavirin all received the ribavirin-containing regimen. The primary endpoint was a sustained virological response (HCV RNA <25 IU/mL) 12 weeks after the end of treatment (SVR12). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT01685203. FINDINGS: Between Aug 14, 2012, and Nov 19, 2013, 467 patients with HCV infection were screened, of whom 174 were infected with genotype 4. 135 patients were randomly assigned to treatment and received at least one dose of study medication; 86 patients were treatment-naive, of whom 44 received ombitasvir plus paritaprevir plus ritonavir and 42 received ombitasvir plus paritaprevir plus ritonavir with ribavirin, and 49 treatment-experienced patients received the ribavirin-containing regimen. In previously untreated patients, SVR12 rates were 100% (42/42 [95% CI 91·6-100]) in the ribavirin-containing regimen and 90·9% (40/44 [95% CI 78·3-97·5]) in the ribavirin-free regimen. No statistically significant differences in SVR12 rates were noted between the treatment-naive groups (mean difference -9·16% [95% CI -19·61 to 1·29]; p=0·086). All treatment-experienced patients achieved SVR12 (49/49; 100% [95% CI 92·7-100]). In the ribavirin-free group, two (5%) of 42 treatment-naive patients had virological relapse, and one (2%) of 44 had virological breakthrough; no virological failures were recorded in the ribavirin-containing regimen. The most common adverse event was headache (14 [29%] of 49 treatment-experienced patients and 14 [33%] of 42 treatment-naive patients). No adverse event-related discontinuations or dose interruptions of study medications, including ribavirin, were noted, and only four patients (4%) of 91 receiving ribavirin required dose modification for haemoglobin less than 100 g/L or anaemia. INTERPRETATION: An interferon-free regimen of ombitasvir plus paritaprevir plus ritonavir with or without ribavirin achieved high sustained virological response rates at 12 weeks after the end of treatment and was generally well tolerated, with low rates of anaemia and treatment discontinuation in non-cirrhotic previously untreated and previously treated patients with HCV genotype 4 infection. FUNDING: AbbVie.

Efficacy and Safety of Ombitasvir, Paritaprevir, and Ritonavir in an Open-Label Study of Patients With Genotype 1b Chronic Hepatitis C Virus Infection With and Without Cirrhosis.

BACKGROUND & AIMS: Interferon-free treatment options are rapidly evolving for patients with chronic hepatitis C virus (HCV) genotype 1b (GT1b) infection with cirrhosis and for nonresponders to prior pegylated interferon and ribavirin therapy. We performed a phase 2b, open-label trial of the combination of ombitasvir (a NS5A replication complex inhibitor), paritaprevir, and ritonavir (an NS3/4A protease inhibitor)-an interferon- and ribavirin-free regimen-in difficult-to-treat patients, including prior null responders and patients with cirrhosis. METHODS: In an international study, 82 patients without cirrhosis (42 treatment-naive and 40 prior null responders) and 99 with cirrhosis (47 treatment-naive and 52 treatment-experienced with prior relapse or a null or partial response) with chronic HCV GT1b infection received ombitasvir (25 mg), paritaprevir (150 mg), and ritonavir (100 mg) once daily for 12 weeks (without cirrhosis) or 24 weeks (with cirrhosis). The primary efficacy endpoint was sustained virologic response 12 weeks after the end of treatment (SVR12). RESULTS: In treatment-naive and null responder patients without cirrhosis, rates of SVR12 were 95.2% and 90.0%, respectively. In treatment-naive and treatment-experienced patients with cirrhosis, rates of SVR12 were 97.9% and 96.2%, respectively. No clinically meaningful differences in rates of SVR12 were observed between patients with or without cirrhosis. Virologic relapse occurred in 3 null responders without cirrhosis and 1 with cirrhosis; virologic breakthrough occurred in 1 null responder without cirrhosis. Common adverse events included headache, asthenia, pruritus, and diarrhea. One patient discontinued taking the drugs because of treatment-related adverse events. CONCLUSIONS: An interferon- and ribavirin-free regimen of ombitasvir, paritaprevir, and ritonavir, achieved high rates of SVR12 in patients with HCV GT1b infection with and without cirrhosis. This regimen was well tolerated and was associated with low rates of treatment discontinuation. ClinicalTrials.gov no: NCT01685203.

Randomized trial of interferon- and ribavirin-free ombitasvir/paritaprevir/ritonavir in treatment-experienced hepatitis C virus-infected patients.

UNLABELLED: Approximately 2 million Japanese individuals are infected with hepatitis C virus and are at risk for cirrhosis, end-stage liver disease, and hepatocellular carcinoma. Patients in whom interferon (IFN)/ribavirin (RBV) therapy has failed remain at risk as effective therapeutic options are limited. This phase 2, randomized, open-label study evaluated an IFN- and RBV-free regimen of once-daily ombitasvir (ABT-267), an NS5A inhibitor, plus paritaprevir (ABT-450), an NS3/4A protease inhibitor dosed with ritonavir (paritaprevir/ritonavir), in pegylated IFN/RBV treatment-experienced Japanese patients with hepatitis C virus subtype 1b or genotype 2 infection. Patients without cirrhosis (aged 18-75 years) with subtype 1b infection received ombitasvir 25 mg plus paritaprevir/ritonavir 100/100 mg or 150/100 mg for 12 or 24 weeks; patients with genotype 2 infection received ombitasvir 25 mg plus paritaprevir/ritonavir 100/100 mg or 150/100 mg for 12 weeks. Sustained virologic response (SVR) at posttreatment week 24 (SVR24 ) was the primary endpoint. Adverse events were collected throughout the study. One hundred ten patients received ≥1 dose of study medication. In the subtype 1b cohort, SVR24 rates were high (88.9%-100%) regardless of paritaprevir dose or treatment duration. In the genotype 2 cohort, SVR24 rates were 57.9% and 72.2% with 100 mg and 150 mg of paritaprevir, respectively. The SVR24 rate was higher in patients with subtype 2a (90%) than 2b (27%). Concordance between SVR12 and SVR24 was 100%. The most common adverse events overall were nasopharyngitis (29%) and headache (14%). CONCLUSION: In this difficult-to-treat population of patients in whom prior pegylated IFN/RBV had failed, ombitasvir/paritaprevir/ritonavir demonstrated potent antiviral activity with a favorable safety profile among Japanese patients with hepatitis C virus genotype 1b or 2a infection.

Randomized phase 3 trial of ombitasvir/paritaprevir/ritonavir for hepatitis C virus genotype 1b-infected Japanese patients with or without cirrhosis.

UNLABELLED: GIFT-I is a phase 3 trial evaluating the efficacy and safety of a 12-week regimen of coformulated ombitasvir (OBV)/paritaprevir (PTV)/ritonavir (r) for treatment of Japanese hepatitis C virus genotype 1b-infected patients. It consists of a double-blind, placebo-controlled substudy of patients without cirrhosis and an open-label substudy of patients with compensated cirrhosis. Patients without cirrhosis were randomized 2:1 to once-daily OBV/PTV/r (25 mg/150 mg/100 mg; group A) or placebo (group B). Patients with cirrhosis received open-label OBV/PTV/r (group C). The primary efficacy endpoint was the rate of sustained virological response 12 weeks posttreatment in interferon-eligible, treatment-naive patients without cirrhosis and hepatitis C virus RNA ≥100,000 IU/mL in group A. A total of 321 patients without cirrhosis were randomized and dosed with double-blind study drug (106 received double-blind placebo and later received open-label OBV/PTV/r), and 42 patients with cirrhosis were enrolled and dosed with open-label OBV/PTV/r. In the primary efficacy population, the rate of sustained virological response 12 weeks posttreatment was 94.6% (106/112, 95% confidence interval 90.5-98.8). Sustained virological response 12 weeks posttreatment rates were 94.9% (204/215) in group A, 98.1% (104/106) in group B (open-label), and 90.5% (38/42) in group C. Overall, virological failure occurred in 3.0% (11/363) of patients who received OBV/PTV/r. The rate of discontinuation due to adverse events was 0%-2.4% in the three patient groups receiving OBV/PTV/r. The most frequent adverse event in patients in any group was nasopharyngitis. CONCLUSION: In this broad hepatitis C virus genotype 1b-infected Japanese patient population with or without cirrhosis, treatment with OBV/PTV/r for 12 weeks was highly effective and demonstrated a favorable safety profile.

Hepatitis C virus genotype 4 resistance and subtype demographic characterization of patients treated with ombitasvir plus paritaprevir/ritonavir.

Hepatitis C virus (HCV) genotype 4 (GT4) is genetically diverse, with 17 confirmed subtypes, and comprises approximately 13% of infections worldwide. In this study, we identified GT4 subtypes by phylogenetic analysis, assessed differences in patient demographics across GT4 subtypes, examined baseline sequence variability among subtypes and the potential impact on treatment outcome, and analyzed the development of viral resistance in patients who received a regimen of ombitasvir (nonstructural protein 5A [NS5A] inhibitor) plus ritonavir-boosted paritaprevir (NS3/4A inhibitor) with or without ribavirin (RBV) for the treatment of HCV GT4 infection. Phylogenetic analysis of HCV NS3/4A, NS5A, and NS5B nucleotide sequences identified 7 subtypes (4a, 4b, 4c, 4d, 4f, 4g/4k, and 4o) among 132 patient samples. Subtype prevalence varied by country, and the distributions of patient birth cohort and race were significantly different across GT4 subtypes 4a, 4d, and non-4a/4d. Baseline amino acid variability was detected in NS5A across GT4 subtypes but had no impact on treatment outcome. Three patients experienced virologic failure and were infected with subtype 4d, and the predominant resistance-associated variants at the time of failure were D168V in NS3 and L28V in NS5A. Overall, high response rates were observed among patients infected with 7 HCV GT4 subtypes, with no impact of baseline variants on treatment outcome. GT4 subtype distribution in this study differed based on patient demographics and geography.

Comparison of two quantitative real-time CMV-PCR tests calibrated against the 1st WHO international standard for viral load monitoring of renal transplant patients.

Cytomegalovirus (CMV) replication in organ transplant recipients is commonly diagnosed by quantitative PCR methods. However, there has been a poor inter-laboratory correlation of viral load values due to the lack of an international reference standard. In a recent study, the COBAS® AmpliPrep/COBAS® TaqMan® (CAP/CTM) CMV test calibrated to the 1st WHO CMV standard, showed good reproducibility in CMV load values across multiple laboratories. Fifty-seven follow-up plasma specimens from 10 kidney transplant recipients with CMV replication were examined using the new quantitative CAP/CTM CMV test and the "in-house" quantitative CMV real-time PCR method, also calibrated against the 1st WHO CMV standard for their clinical applicability for monitoring CMV load in renal transplant patients. By CAP/CTM CMV test 49/57 specimens were CMV-DNA positive compared to 44/57 by the "in-house" PCR test. The "in-house" PCR and CAP/CTM CMV test correlated well in monitoring individual kidney transplant patients. Conversion of the CMV-DNA copies to IUs made the results of the "in-house" PCR and CAP/CTM CMV test less uniform in analysis of the patient samples. In specimens of one patient, significant underquantification of CMV load with "in-house" PCR emerged during follow-up due to a point mutation in the "in-house" PCR primer sequence. The CAP/CTM CMV test was found suitable for diagnosing and monitoring CMV replication in renal transplant patients. Multicenter studies are needed to provide more information of the commutability of the 1st WHO CMV standard and to define the clinical thresholds.

Molecular diagnostics in the management of chronic hepatitis C: key considerations in the era of new antiviral therapies.

Molecular tests that detect and/or quantify HCV RNA are important in the diagnosis and management of patients with chronic hepatitis C (CHC) undergoing anti-viral therapy. The primary goal of anti-HCV therapy is to achieve a sustained virologic response (SVR) defined as "undetectable" Hepatitis C Virus (HCV) RNA in the serum or plasma at 12 to 24 weeks following the end of treatment.

An international multicenter performance analysis of cytomegalovirus load tests.

BACKGROUND: Quantification of cytomegalovirus (CMV) load is central to the management of CMV infections in immunocompromised patients, but quantitative results currently differ significantly across methods and laboratories. METHODS: The COBAS AmpliPrep/COBAS TaqMan CMV Test (CAP/CTM CMV test), developed using the first World Health Organization CMV standard in the calibration process, was compared to local assays used by 5 laboratories at transplant centers in the United States and Europe. Blinded plasma panels (n = 90) spiked with 2.18-6.7 log(10) copies/mL and clinical plasma samples from immunocompromised patients (n = 660) were tested. RESULTS: Observed mean panel member concentrations by site and 95% confidence intervals (CIs) of the data combined across sites were narrower for CAP/CTM CMV test compared with local assays. The 95% CI in log(10) copies/mL of the combined data per panel member for CAP/CTM CMV test vs comparator assays was .17 vs 1.5 at 2.18 log(10) copies/mL; .14 vs .52 at 2.74 log(10) copies/mL; .16 vs .6 at 3.3 log(10) copies/mL; .2 vs 1.11 at 4.3 log(10) copies/mL; .21 vs 1.13 at 4.7 log(10) copies/mL; and .18 vs 1.4 at 6.7 log(10) copies/mL. In clinical specimens, constant and variable quantification differences between the CAP/CTM CMV test and comparator assays were observed. CONCLUSIONS: High interlaboratory agreement and precision of CAP/CTM CMV test results across 5 different laboratories over 4 orders of magnitude suggest that this assay could be valuable in prospective studies identifying clinical viral load thresholds for CMV treatment.

HCV RNA viral load assessments in the era of direct-acting antivirals.

Recent regulatory approvals of the NS3/4A protease inhibitors boceprevir and telaprevir launched a new therapeutic era for hepatitis C virus (HCV) genotype 1 infection. Decisions to shorten, extend, or stop treatment with these direct-acting antiviral (DAA) regimens require accurate quantification of serum HCV RNA levels. To effectively use DAA therapies, clinicians must understand performance characteristics of HCV RNA real-time PCR assays and the clinical significance of HCV RNA that is detectable below the lower limit of quantification. This review summarizes terms used to report HCV RNA viral load results, explains the analytical performance of the PCR assay used in the clinical trials of boceprevir and telaprevir, and compares currently available commercial assays.

Polyomavirus JC urinary shedding in kidney and liver transplant recipients associated with reduced creatinine clearance.

BACKGROUND: Polyomavirus reactivation can cause significant morbidity in solid organ transplant recipients, particularly BK virus (BKV) in kidney transplant patients. Less is known about dynamics of John Cunningham virus (JCV) in nonkidney organ transplant patients. METHODS: We examined the frequency of urinary shedding of polyomaviruses BKV and JCV and their relationship to creatinine clearance (CrCl) in a longitudinal study of 41 kidney and 33 liver transplant recipients. RESULTS: Any polyomavirus urinary shedding was more frequent in liver than kidney recipients (64% vs 39%; P= .03). JCV was excreted more frequently by liver than kidney recipients (71% vs 38%), whereas BKV was shed more often by kidney than liver patients (69% vs 52%). Mean JCV loads were significantly higher than those of BKV in both patient groups (P< .0001). Lower mean CrCl values were significantly associated with JCV shedding in both kidney and liver recipients (P< .001). CONCLUSIONS: These findings suggest that BKV and JCV display different patterns of reactivation and shedding in kidney and liver transplant patients and that JCV may have a role in renal dysfunction in some solid organ transplant recipients.

Population Pharmacokinetic Analysis to Assist Dose Selection of the L-Ornithine Salt of Phenylacetic Acid.

BACKGROUND AND OBJECTIVE: L-Ornithine phenylacetate is an intravenous formulation of the L-ornithine salt of phenylacetic acid under development for the treatment of hepatic encephalopathy. Very limited clinical data in patients are available, with a phase II study in target patients not designed for dose finding, to support phase III dose selection in a global development program. The objective of the present population pharmacokinetic modeling and simulation was to evaluate dose selection for target patient populations with a low body weight, ethnicity, and hepatic impairment in a global clinical study. METHODS: A population pharmacokinetic model was developed based on plasma concentrations of L-ornithine, phenylacetic acid, and phenylacetylglutamine data from four clinical trials in healthy subjects and patients with stable cirrhosis or hospitalized adult patients with liver cirrhosis and hepatic encephalopathy. A covariate analysis was conducted to identify source of variability to support dose selection for global clinical development of L-ornithine phenylacetate. Phenylacetylglutamine formation in the pharmacokinetic model also quantified pharmacodynamic effects measured by ammonia removal. RESULTS: Body weight and hepatic function were significant covariates determining phenylacetic acid exposure. After accounting for body weight, there was no difference between tested Caucasian and Asian populations in phenylacetic acid exposure. Renal dysfunction significantly reduced phenylacetylglutamine excretion. However, renal impairment had no impact on plasma phenylacetic acid and free ammonia levels. Exploratory modeling suggested that L-ornithine might enhance the removal of ammonia. CONCLUSIONS: With a flat dosing algorithm, special consideration must be given to patients with a small body size (i.e., body weight ≤ 50 kg) and severe hepatic impairment.

Exposures of Phenylacetic Acid and Phenylacetylglutamine Across Different Subpopulations and Correlation with Adverse Events.

BACKGROUND: Elevated plasma ammonia is central to the pathogenesis of hepatic encephalopathy. Sodium phenylacetate or glycerol phenylbutyrate is approved for urea cycle disorders, but limited clinical data are available for hepatic encephalopathy. Phenylacetic acid (PAA) plasma exposure has been reported to correlate with neurologic adverse events in patients with cancer but not in patients with urea cycle disorders or hepatic encephalopathy. Ornithine phenylacetate, an intravenous dosage form of the L-ornithine salt of phenylacetate, is under development for hepatic encephalopathy. OBJECTIVE: This analysis summarized the pharmacokinetics and safety of ornithine phenylacetate to support the dosing strategy and to assist with the monitoring and management of neurologic adverse events in a global clinical development program. METHODS: Phenylacetic acid and phenylacetylglutamine (PAGN) pharmacokinetic data and adverse events from five clinical studies were included in the analysis. Hepatic and renal dysfunction were assessed by baseline Child-Pugh score and creatinine clearance, respectively. Predicted plasma exposures of PAA at the occurrence of neurologic adverse events were used for exposures and neurologic adverse event analysis. RESULTS: Phenylacetic acid exhibited nonlinear pharmacokinetics. Phenylacetic acid exposure was 35% higher in Child-Pugh C than in Child-Pugh B. No significant pharmacokinetic difference was identified between Caucasian and Asian subjects after body weight adjustment. Phenylacetylglutamine renal clearance decreased by five-fold in severe renal impairment compared with subjects with normal renal function. Renal dysfunction significantly elevated PAGN plasma concentrations; however, elevated PAGN due to reduced excretion of PAGN did not change PAA exposure and plasma ammonia levels. No correlation was observed between PAA plasma exposure and neurologic adverse events in patients with stable cirrhosis or acute hepatic encephalopathy. CONCLUSIONS: Dose adjustment should be considered for patients with low body weight and severely impaired hepatic function. Phenylacetic acid plasma exposure was not correlated with neurologic adverse events in the ornithine phenylacetate target patient population.

Influence of the viral regulatory region on tumor induction by simian virus 40 in hamsters.

Most of the simian virus 40 (SV40) genome is conserved among isolates, but the noncoding regulatory region and the genomic region encoding the large T-antigen C terminus (T-ag-C) may exhibit considerable variation. We demonstrate here that SV40 isolates differ in their oncogenic potentials in Syrian golden hamsters. Experimental animals were inoculated intraperitoneally with 10(7) PFU of parental or recombinant SV40 viruses and were observed for 12 months to identify genetic determinants of oncogenicity. The viral regulatory region was found to exert a statistically significant influence on tumor incidence, whereas the T-ag-C played a minor role. Viruses with a single enhancer (1E) were more oncogenic than those with a two-enhancer (2E) structure. Rearrangements in the 1E viral regulatory region were detected in 4 of 60 (6.7%) tumors. Viral loads in tumors varied, with a median of 5.4 SV40 genome copies per cell. Infectious SV40 was rescued from 15 of 37 (40%) cell lines established from tumors. Most hamsters with tumors and many without tumors produced antibodies to T antigen. All viruses displayed similar transforming frequencies in vitro, suggesting that differences in oncogenic potential in vivo were due to host responses to viral infection. This study shows that SV40 strains differ in their biological properties, suggests that SV40 replicates to some level in hamsters, and indicates that the outcome of an SV40 infection may depend on the viral strain present.

Detection of polyomavirus SV40 in tonsils from immunocompetent children.

BACKGROUND: BK virus (BKV), JC virus (JCV) and simian virus 40 (SV40) are nonenveloped DNA viruses, members of the family Polyomaviridae. BK and JC viruses establish persistent infections in humans, and evidence suggests that SV40 can infect humans, as well. Whether persistence occurs in the lymphoid system is unknown. METHODS: Paraffin-embedded tonsils from 220 immunocompetent children (mean age 9.3 years) were examined by polymerase chain reaction (PCR) to detect viral DNA of BKV, JCV, SV40, and Epstein-Barr virus (EBV). RESULTS: Polyomavirus-specific DNA sequences were detected in 8.3% (29/351) of specimens collected from 220 children. Twenty-one (9.5%) children had polyomavirus DNA present in at least one tonsil, with sequences identified as SV40 (n=20) and BKV (n=1). Polyomavirus JCV was not detected. Among patients positive for SV40, 8 of 14 (57%) contained viral DNA in both available tonsils. EBV DNA was detected in 99 (28.2%) samples from 67 (30.5%) patients. Eleven samples (3.1%) from 8 (3.6%) children were positive for both polyomavirus and EBV. SV40-positive children were significantly older than the SV40-negative subjects (P<0.001). T-antigen expression was detected in an SV40 DNA-positive tonsil by immunohistochemistry. CONCLUSIONS: These results suggest that SV40 can infect tonsils, that lymphoid tissue may represent a site for polyomavirus persistence, and that immunohistochemistry is not a useful detection assay when there are very few virus-infected cells in a tissue.

Simian virus 40 in posttransplant lymphoproliferative disorders.

Simian virus 40 (SV40) is an oncogenic DNA virus, which is an emergent pathogen implicated in some human malignancies, including B-cell lymphomas. As with other malignancies that occur during immunosuppression, it is hypothesized that SV40 infections may be associated with some posttransplant lymphoproliferative disorders (PTLDs). Specimens were tested initially for Epstein-Barr virus (EBV) by in situ hybridization for EBV-encoded small RNA and/or by immunohistochemical staining for EBV-latent membrane protein 1. Coded DNA specimens extracted from formalin-fixed, paraffin-embedded tissues from 22 PTLD cases were examined by polymerase chain reaction using primers for the SV40 large tumor antigen (T-ag) gene and confirmed by sequence analysis. In addition, samples were assessed for the expression of SV40 T-ag by immunohistochemical staining. Epstein-Barr virus was detected in 18 (82%) of 22 PTLD cases. Simian virus 40 T-ag sequences were detected in 2 (13%) of the 16 cases with amplifiable DNA: one with EBV-negative T-cell PTLD and the other with EBV-positive B-cell monomorphic PTLD. Immunohistochemical staining showed expression of SV40 T-ag in 1 of 2 cases containing viral DNA sequences and in none of the SV40 T-ag DNA-negative samples. Expression of SV40 T-ag was restricted to malignant cells and not to reactive lymphocytes. These results suggest that SV40 may be associated with a small subset of PTLD cases. Additional studies are needed to determine the role of SV40 in EBV-negative PTLD.

SV40 in human brain cancers and non-Hodgkin's lymphoma.

Simian virus 40 (SV40) is a potent DNA tumor virus that is known to induce primary brain cancers and lymphomas in laboratory animals. SV40 oncogenesis is mediated by the viral large tumor antigen (T-ag), which inactivates the tumor-suppressor proteins p53 and pRb family members. During the last decade, independent studies using different molecular biology techniques have shown the presence of SV40 DNA, T-ag, or other viral markers in primary human brain cancers, and a systematic assessment of the data indicates that the virus is significantly associated with this group of human tumors. In addition, recent large independent studies showed that SV40 T-ag DNA is significantly associated with human non-Hodgkin's lymphoma (NHL). Although the prevalence of SV40 infections in humans is not known, numerous observations suggest that SV40 is a pathogen in the human population today. This review examines the molecular biology, pathology, and clinical data implicating SV40 in the pathogenesis of primary human brain cancers and NHL and discusses future research directions needed to define a possible etiologic role for SV40 in these malignancies.

Specific and quantitative detection of human polyomaviruses BKV, JCV, and SV40 by real time PCR.

BACKGROUND: The polyomaviruses that infect humans, BK virus (BKV), JC virus (JCV), and simian virus 40 (SV40), typically establish subclinical persistent infections. However, reactivation of these viruses in immunocompromised hosts is associated with renal nephropathy and hemorrhagic cystitis (HC) caused by BKV and with progressive multifocal leukoencephalopathy (PML) caused by JCV. Additionally, SV40 is associated with several types of human cancers including primary brain and bone cancers, mesotheliomas, and non-Hodgkin's lymphoma. Advancements in detection of these viruses may contribute to improved diagnosis and treatment of affected patients. OBJECTIVE: To develop sensitive and specific real time quantitative polymerase chain reaction (RQ-PCR) assays for the detection of T-antigen DNA sequences of the human polyomaviruses BKV, JCV, and SV40 using the ABI Prism 7000 Sequence Detection System. STUDY DESIGN: Assays for absolute quantification of the viral T-ag sequences were designed and the sensitivity and specificity were evaluated. A quantitative assay to measure the single copy human RNAse P gene was also developed and evaluated in order to normalize viral gene copy numbers to cell numbers. RESULTS: Quantification of the target genes is sensitive and specific over a 7 log dynamic range. Ten copies each of the viral and cellular genes are reproducibly and accurately detected. The sensitivity of detection of the RQ-PCR assays is increased 10- to 100-fold compared to conventional PCR and agarose gel protocols. The primers and probes used to detect the viral genes are specific for each virus and there is no cross reactivity within the dynamic range of the standard dilutions. The sensitivity of detection for these assays is not reduced in human cellular extracts; however, different DNA extraction protocols may affect quantification. CONCLUSION: These assays provide a technique for rapid and specific quantification of polyomavirus genomes per cell in human samples.

Lymphoproliferative disorders in Costa Rica and simian virus 40.

BACKGROUND AND OBJECTIVES: Simian virus 40 (SV40) is an oncogenic DNA virus implicated in some human malignancies, including lymphomas. In the present masked case-control study, we investigated the prevalence of SV40 sequences and the expression of the viral oncoprotein, large tumor antigen (T-ag), in lymphomas and control specimens from patients negative for the human immunodeficiency virus in Costa Rica. DESIGN AND METHODS: Coded specimens were anlyzed by polymerase chain reaction for SV40 and Epstein-Barr virus (EBV). SV40 sequences were confirmed by Southern blot and DNA sequence analysis. Immunohistochemistry was used to detect the expression of SV40 T-ag in coded samples and to immunophenotype the lymphomas. RESULTS: When samples were decoded, SV40 DNA sequences were detected significantly more often in lymphomas than in control samples (30/125, 24% vs. 0/91, 0%; p=0.001). SV40 DNA was detected in 26% and 10% of non-Hodgkin's and Hodgkin's lymphomas, respectively. EBV DNA was detected in 10% of lymphomas and 33% of control specimens. None of the lymphomas was positive for both SV40 and EBV. Expression of SV40 T-ag was detected in 64% of B-cell lymphomas that contained T-ag DNA sequences and in none of the samples negative for viral DNA. Not all cells in a positive tumor expressed T-ag and the reactions were relatively low intensity. A germinal center B-cell-like profile was frequently associated with SV40-positive lymphomas. Of note, 20% of patients with SV40-related lymphomas were born in the 1970s and 1980s. INTERPRETATION AND CONCLUSIONS: These results indicate that SV40 is significantly associated with some B-cell neoplasms in Costa Rica today.