Medicaid Value-Based Payments and Health Care Use for Patients With Mental Illness

Importance

Medicaid patients with mental illness comprise one of the most high-need and complex patient populations. Value-based reforms aim to improve care, but their efficacy in the Medicaid program is unclear.

Objective

To investigate if New York state's Medicaid value-based payment reform was associated with improved utilization patterns for patients with mental illness.

Design, Setting, and Participants

This retrospective cohort study used a difference-in-differences analysis to compare changes in utilization between Medicaid beneficiaries whose outpatient practices participated in value-based payment reform and beneficiaries whose practices did not participate from before (July 1, 2013-June 30, 2015) to after reform (July 1, 2015-June 30, 2019). Participants were Medicaid beneficiaries in New York state aged 18 to 64 years with major depression disorder, bipolar disorder, and/or schizophrenia. Data analysis was performed from April 2021 to July 2023.

Exposure

Beneficiaries were exposed to value-based payment reforms if their attributed outpatient practice participated in value-based payment reform at baseline (July 1, 2015).

Main Outcomes and Measures

Primary outcomes were the number of outpatient primary care visits and the number of behavioral health visits per year. Secondary outcomes were the number of mental health emergency department visits and hospitalizations per year.

Results

The analytic population comprised 306 290 individuals with depression (67.4% female; mean [SD] age, 38.6 [11.9] years), 85 105 patients with bipolar disorder (59.6% female; mean [SD] age, 38.0 [11.6] years), and 71 299 patients with schizophrenia (45.1% female; mean [SD] age, 40.3 [12.2] years). After adjustment, analyses estimated a statistically significant, positive association between value-based payments and behavioral health visits for patients with depression (0.91 visits; 95% CI, 0.51-1.30) and bipolar disorder (1.01 visits; 95% CI, 0.22-1.79). There was no statistically significant changes to primary care visits for patients with depression and bipolar disorder, but value-based payments were associated with reductions in primary care visits for patients with schizophrenia (-1.31 visits; 95% CI, -2.51 to -0.12). In every diagnostic population, value-based payment was associated with significant reductions in mental health emergency department visits (population with depression: -0.01 visits [95% CI, -0.02 to -0.002]; population with bipolar disorder: -0.02 visits [95% CI, -0.05 to -0.001]; population with schizophrenia: -0.04 visits [95% CI, -0.07 to -0.01]).

Conclusions and Relevance

In this cohort study, Medicaid value-based payment reform was statistically significantly associated with an increase in behavioral health visits and a reduction in mental health emergency department visits for patients with mental illness. Medicaid value-based payment may be effective at altering health care utilization in patients with mental illness.

Hospital concentration and low-income populations: Evidence from New York State Medicaid

While a large body of evidence has examined hospital concentration, its effects on health care for low-income populations are less explored. We use comprehensive discharge data from New York State to measure the effects of changes in market concentration on hospital-level inpatient Medicaid volumes. Holding fixed hospital factors constant, a one percent increase in HHI leads to a 0.6% (s.e. = 0.28%) decrease in the number of Medicaid admissions for the average hospital. The strongest effects are on admissions for birth (-1.3%, s.e. = 0.58%). These average hospital-level decreases largely reflect redistribution of Medicaid patients across hospitals, rather than overall reductions in hospitalizations for Medicaid patients. In particular, hospital concentration leads to a redistribution of admissions from non-profit hospitals to public hospitals. We find evidence that for births, physicians serving high shares of Medicaid beneficiaries in particular experience reduced admissions as concentration increased. These reductions may reflect preferences among these physicians or reduced admitting privileges by hospitals as a means to screen out Medicaid patients.

The Role Of Financial Incentives In Biosimilar Uptake In Medicare: Evidence From The 340B Program

Biosimilar drugs-lower-cost alternatives to expensive biologic drugs-have the potential to slow the growth of US drug spending. However, rates of biosimilar uptake have varied across hospital outpatient providers. We investigated whether the 340B Drug Pricing Program, which offers eligible hospitals substantial discounts on drug purchases, inhibits biosimilar uptake. Almost one-third of US hospitals participate in the 340B program. Using a regression discontinuity design and two high-volume biologics with biosimilar competitors, filgrastim and infliximab, we estimated that 340B program eligibility was associated with a 22.9-percentage-point reduction in biosimilar adoption. In addition, 340B program eligibility was associated with 13.3 more biologic administrations annually per hospital and $17,919 more biologic revenue per hospital. Our findings suggest that the program inhibited biosimilar uptake, possibly as a result of financial incentives making reference drugs more profitable than biosimilar medications.

Effects of Real-time Prescription Benefit Recommendations on Patient Out-of-Pocket Costs: A Cluster Randomized Clinical Trial

Importance

Rising drug costs contribute to medication nonadherence and adverse health outcomes. Real-time prescription benefit (RTPB) systems present prescribers with patient-specific out-of-pocket cost estimates and recommend lower-cost, clinically appropriate alternatives at the point of prescribing.

Objective

To investigate whether RTPB recommendations lead to reduced patient out-of-pocket costs for medications.

Design, Setting, and Participants

In this cluster randomized trial, medical practices in a large, urban academic health system were randomly assigned to RTPB recommendations from January 13 to July 31, 2021. Participants were adult patients receiving outpatient prescriptions during the study period. The analysis was limited to prescriptions for which RTPB could recommend an available alternative. Electronic health record data were used to analyze the intervention's effects on prescribing. Data analyses were performed from August 20, 2021, to June 8, 2022.

Interventions

When a prescription was initiated in the electronic health record, the RTPB system recommended available lower-cost, clinically appropriate alternatives for a different medication, length of prescription, and/or choice of pharmacy. The prescriber could select either the initiated order or one of the recommended options.

Main Outcomes and Measures

Patient out-of-pocket cost for a prescription. Secondary outcomes were whether a mail-order prescription and a 90-day supply were ordered.

Results

Of 867 757 outpatient prescriptions at randomized practices, 36 419 (4.2%) met the inclusion criteria of having an available alternative. Out-of-pocket costs were $39.90 for a 30-day supply in the intervention group and $67.80 for a 30-day supply in the control group. The intervention led to an adjusted 11.2%; (95% CI, -15.7% to -6.4%) reduction in out-of-pocket costs. Mail-order pharmacy use was 9.6% and 7.6% in the intervention and control groups, respectively (adjusted 1.9 percentage point increase; 95% CI, 0.9 to 3.0). Rates of 90-day supply were not different. In high-cost drug classes, the intervention reduced out-of-pocket costs by 38.9%; 95% CI, -47.6% to -28.7%.

Conclusions and Relevance

This cluster randomized clinical trial showed that RTPB recommendations led to lower patient out-of-pocket costs, with the largest savings occurring for high-cost medications. However, RTPB recommendations were made for only a small percentage of prescriptions.

Trial Registration

ClinicalTrials.gov Identifier: NCT04940988; American Economic Association Registry: AEARCTR-0006909.

Association of Insurance Mix and Diagnostic Coding Practices in New York State Hospitals

Question

What is the association between a hospital’s share of privately insured patients and diagnostic coding practices?

Findings

Analyses of 1 614 630 New York Medicaid admissions indicate that for a given patient with multiple hospitalizations, the number of diagnoses on a claim was positively associated with the hospital’s share of privately insured patients. Patients discharged from hospitals in the bottom quartile by share of privately insured patients were coded with 1 to 2 additional diagnoses when they were subsequently discharged from hospitals in the top quartile.

Meaning

Payer mix is associated with diagnostic coding patterns, suggesting that payment policy may be influencing investments in administrative infrastructure.

Importance

Given higher reimbursement rates, hospitals primarily serving privately insured patients may invest more in intensive coding than hospitals serving publicly insured patients. This may lead these hospitals to code more diagnoses for all patients.

Objective

To estimate whether, for the same Medicaid enrollee with multiple hospitalizations, a hospital’s share of privately insured patients is associated with the number of diagnoses on claims.

Design, Setting, and Participants

This cross-sectional study used patient-level fixed effects regression models on inpatient Medicaid claims from Medicaid enrollees with at least 2 admissions in at least 2 different hospitals in New York State between 2010 and 2017. Analyses were conducted from 2019 to 2021.

Exposures

The annual share of privately insured patients at the admitting hospital.

Main Outcomes and Measures

Number of diagnostic codes per admission. Probability of diagnoses being from a list of conditions shown to be intensely coded in response to payment incentives.

Results

This analysis included 1 614 630 hospitalizations for Medicaid-insured patients (mean [SD] age, 48.2 [20.1] years; 829 684 [51.4%] women and 784 946 [48.6%] men). Overall, 74 998 were Asian (4.6%), 462 259 Black (28.6%), 375 591 Hispanic (23.3%), 486 313 White (30.1%), 128 896 unknown (8.0%), and 86 573 other (5.4%). When the same patient was seen in a hospital with a higher share of privately insured patients, more diagnoses were recorded (0.03 diagnoses per percentage point [pp] increase in share of privately insured; 95% CI, 0.02-0.05; P < .001). Patients discharged from hospitals in the bottom quartile of privately insured patient share received 1.37 more diagnoses when they were subsequently discharged from hospitals in the top quartile, relative to patients whose admissions were both in the bottom quartile (95% CI, 1.21-1.53; P < .001). Those going from hospitals in the top quartile to the bottom had 1.67 fewer diagnoses (95% CI, −1.84 to −1.50; P < .001). Diagnoses in hospitals with a higher private payer share were more likely to be for conditions sensitive to payment incentives (0.08 pp increase for each pp increase in private share; 95% CI, 0.06-0.10; P < .001). These findings were replicated in 2016 to 2017 data.

Conclusions and Relevance

In this cross-sectional study of Medicaid enrollees, admission to a hospital with a higher private payer share was associated with more diagnoses on Medicaid claims. This suggests payment policy may drive differential investments in infrastructure to document diagnoses. This may create a feedback loop that exacerbates resource inequity.

Identifying high-value care for Medicare beneficiaries: a cross-sectional study of acute care hospitals in the USA

OBJECTIVES

High-value care is providing high quality care at low cost; we sought to define hospital value and identify the characteristics of hospitals which provide high-value care.

DESIGN

Retrospective observational study.

SETTING

Acute care hospitals in the USA.

PARTICIPANTS

All Medicare beneficiaries with claims included in Center for Medicare & Medicaid Services Overall Star Ratings or in publicly available Medicare spending per beneficiary data.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcome was value defined as the difference between Star Ratings quality score and Medicare spending; the secondary outcome was classification as a 4 or 5 star hospital with lowest quintile Medicare spending ('high value') or 1 or 2 star hospital with highest quintile spending ('low value').

RESULTS

Two thousand nine hundred and fourteen hospitals had both quality and spending data, and were included. The value score had a mean (SD) of 0.58 (1.79). A total of 286 hospitals were classified as high value; these represented 28.6% of 999 4 and 5 star hospitals and 46.8% of 611 low cost hospitals. A total of 258 hospitals were classified as low value; these represented 26.6% of 970 1 and 2 star hospitals and 49.3% of 523 high cost hospitals. In regression models ownership, non-teaching status, beds, urbanity, nurse to bed ratio, percentage of dual eligible Medicare patients and percentage of disproportionate share hospital payments were associated with the primary value score.

CONCLUSIONS

There are high quality hospitals that are not high value, and a number of factors are strongly associated with being low or high value. These findings can inform efforts of policymakers and hospitals to increase the value of care.

340B Drug Pricing Program and hospital provision of uncompensated care

OBJECTIVES

To evaluate whether hospital entry into the 340B Drug Pricing Program, which entitles eligible hospitals to discounts on drug purchases and intends for hospitals to use associated savings to devote more resources to the care of low-income populations, is associated with changes in hospital provision of uncompensated care.

STUDY DESIGN

We analyzed secondary data on 340B participation and uncompensated care provision among general acute care hospitals and critical access hospitals from 2003 to 2015. We constructed an annual, hospital-level data set on hospital 340B participation from the Office of Pharmacy Information Systems and on uncompensated care provision from the Hospital Cost Reporting Information System.

METHODS

Focusing on 2 periods of program expansion, we separately analyzed trends in uncompensated care costs for 340B-eligible general acute care hospitals and critical access hospitals, stratified by year of 340B program entry, including a stratum of eligible hospitals that never participated. We used a differences-in-differences approach to quantify whether there were differential changes in provision of uncompensated care after hospitals enter the 340B program relative to hospitals that did not participate or had not yet entered.

RESULTS

We do not find evidence that hospitals increased provision of uncompensated care after entry into the 340B program differentially more than hospitals that never entered or had not yet entered the program.

CONCLUSIONS

Relying on hospitals to invest surplus into care for the underserved without marginal incentives to do so or strong oversight may not be an effective strategy to expand safety-net care.

Validation of EHR medication fill data obtained through electronic linkage with pharmacies

BACKGROUND: Recent linkages between electronic health records (EHRs) and pharmacy data hold opportunity for up-to-date assessment of medication adherence at the point of care. OBJECTIVE: To validate linked EHR-pharmacy data, which can be used for point-of-care interventions for concordance with insurance claims data for patients in a large health care delivery system. METHODS: We performed a retrospective cohort study of adult patients with an active antihypertensive medication order and seen as outpatients between August 25, 2019, and August 31, 2019. Pharmacy fill information was obtained from the EHR via linkages with Surescripts pharmacy and pharmacy benefit manager data, as well as from insurance claims available at our institution. We matched antihypertensive medication fills observed in the linked EHR-pharmacy database with available fills in the insurance claims database and calculated the percentage of medication fills that were available in each database. We estimated medication adherence using proportion of days covered in the linked EHR-pharmacy database and in the insurance claims database. RESULTS: Of 26,679 patients with hypertension, 23,348 (87.5%) had at least 1 antihypertensive medication fill recorded in the linked EHR-pharmacy database. Of 1,501 patients matched with the insurance database and with a documented medication fill, a fill was present for 1,484 (98.9%) and 1,259 (83.9%) patients in the linked EHR-pharmacy and insurance databases, respectively. Of 12,109 medication fills recorded in the insurance data, we found an overlap of 11,060 (91.3%) fills with the linked EHR-pharmacy database. The linked EHR-pharmacy database also contained 18,232 of 19,281 (94.6%) medication fills present in either database. Measured medication adherence was higher for patients when based on linked EHR-pharmacy data compared with insurance claims data (42% vs 30%, P < 0.001). CONCLUSIONS: Linked EHR-pharmacy data captured medication fills for the vast majority of patients and resulted in higher estimates of adherence than insurance claims. Our results suggest that pharmacy fill data available in the EHR have sufficient reliability to be used for point-of-care assessment of medication adherence. DISCLOSURES: This study was supported by grant R01HL155149 from the National Heart, Lung, and Blood Institute. Allen Thorpe provided funding for the NYU Langone Health Learning Health System Program, which helped fund this project. The authors have nothing to disclose.

Online Advertising Increased New Hampshire Residents' Use Of Provider Price Tool But Not Use Of Lower-Price Providers

Insurers and policy makers have created health care price transparency websites to facilitate price shopping and reduce spending. However, price transparency tools to date have been plagued by low use. It is unclear whether this low use reflects a lack of interest or a lack of awareness. We launched a large online advertising campaign to increase consumers' awareness about insurer-specific negotiated price information available on New Hampshire's public price transparency website. Our campaign led to a more than 600 percent increase in visits to the website. However, in our analysis of health plan claims, this increased use of the website did not translate to increased use of lower-price providers. Our findings imply that the limited success to date of price transparency tools in reducing health care spending is driven by structural factors that limit consumers' ability to use health care price information as opposed to only a lack of awareness about price transparency tools.

Does Medicaid coverage of Medicare cost sharing affect physician care for dual-eligible Medicare beneficiaries?

OBJECTIVE

To assess changes in physicians' provision of care to duals (low-income individuals with Medicare and Medicaid) in response to a policy that required Medicaid to fully pay Medicare's cost sharing for office visits with these patients. This policy-a provision of the Affordable Care Act-effectively increased payments for office visits with duals by 0%-20%, depending on the state, in 2013 and 2014.

DATA SOURCES

Fee-for-service claims for a 5% random sample of Medicare beneficiaries in 2010-2016.

STUDY DESIGN

We conducted a difference-in-differences analysis to compare changes in office visits among Qualified Medicare Beneficiaries (QMBs)-the largest subpopulation of duals for whom payment rates were affected by this policy-to changes among other low-income Medicare beneficiaries for whom payment rates were unaffected (pooled across all states). Next, we conducted a triple-differences analysis that compared changes between QMBs and other low-income beneficiaries in 33 states with payment rate increases of approximately 20% to analogous changes in 14 states without payment increases.

DATA COLLECTION

The study included administrative Medicare enrollment and claims data for QMBs and a comparison group of other low-income Medicare beneficiaries (1 914 073 beneficiary-years from 2010 to 2016).

PRINCIPAL FINDINGS

Nationally, we did not find a differential increase in office visits among QMBs versus other low-income beneficiaries that coincided with this payment change. In the triple-differences analysis, we did not observe a greater increase in visits among QMBs vs other low-income beneficiaries in states where the policy resulted in large (approximately 20%) increases in payment rates vs states where payment rates were unaffected (triple-differences estimate: -0.12 annual visits, 95% CI: -0.28, 0.04; P = 0.15).

CONCLUSIONS

Physicians' provision of care to low-income Medicare beneficiaries may not be responsive to short-run payment changes.

Emergent Premedication for Contrast Allergy Prior to Endovascular Treatment of Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Management of contrast media allergies may lead to treatment delays in patients with acute ischemic stroke undergoing endovascular therapy. The optimal premedication strategy remains unclear. The aim of this report was to analyze our experience with emergent administration of premedication regimens before endovascular therapy.

MATERIALS AND METHODS

We retrospectively reviewed prospective data for all patients undergoing endovascular therapy from 2012 to 2019 at an academic comprehensive stroke center. Records of patients with documented contrast allergy were reviewed and analyzed. Data collected included stroke risk factors and characteristics, historical contrast reaction details, premedication regimens administered, and signs or symptoms of allergic reaction developing post-endovascular therapy. Hospital arrival time to endovascular therapy was compared with that in those who did not have a history of contrast allergy.

RESULTS

We analyzed 1521 patients undergoing endovascular therapy; 60 (4%) had documented contrast allergies and constituted the study cohort. The median age was 73 years (interquartile range, 66-81 years), and 65% were women. The median time from premedication to contrast was 24 minutes (interquartile range, 0-36 minutes). Forty-three patients (72%) proceeded directly to endovascular therapy; in 17 patients, the first contrast exposure was CTA. Time from hospital arrival to endovascular therapy was not slower for patients with documented allergies (96 versus 134 minutes, P = .32). No patients experienced a contrast media reaction.

CONCLUSIONS

In a single-institution cohort study of 60 consecutive patients with documented contrast allergies undergoing endovascular therapy with emergent premedication en route to (or in) the neuroangiography suite, no patients experienced allergic symptoms. This pragmatic approach may be safe for patients who have documented contrast media allergies.

Predicting outcomes after acute reperfusion therapy for basilar artery occlusion

BACKGROUND AND PURPOSE

Basilar artery occlusion (BAO) leads to high rates of morbidity and mortality, despite successful recanalization. The discordance between flow restoration and long-term functional status clouds clinical decision-making regarding further aggressive care. We sought to develop and validate a practical, prognostic tool for the prediction of 3-month favorable outcome after acute reperfusion therapy for BAO.

METHODS

This retrospective, multicenter, observational study was conducted at four high-volume stroke centers in the USA and Europe. Multivariate regression analysis was performed to identify predictors of favorable outcome (90-day modified Rankin scale scores 0-2) and derive a clinically applicable prognostic model (the Pittsburgh Outcomes after Stroke Thrombectomy-Vertebrobasilar (POST-VB) score). The POST-VB score was evaluated and internally validated with regard to calibration and discriminatory ability. External validity was assessed in patient cohorts at three separate centers.

RESULTS

In the derivation cohort of 59 patients, independent predictors of favorable outcome included smaller brainstem infarct volume on post-procedure magnetic resonance imaging (P < 0.01) and younger age (P = 0.01). POST-VB score was calculated as: age + (10 × brainstem infarct volume). POST-VB score demonstrated excellent discriminatory ability [area under the receiver-operating characteristic curve (AUC) = 0.91] and adequate calibration (P = 0.88) in the derivation cohort (Center A). It performed equally well across the three external validation cohorts (Center B, AUC = 0.89; Center C, AUC = 0.78; Center D, AUC = 0.80). Overall, a POST-VB score < 49 was associated with an 88% likelihood of favorable outcome, as compared to 4% with a score ≥ 125.

CONCLUSIONS

The POST-VB score effectively predicts 3-month functional outcome following acute reperfusion therapy for BAO and may aid in guiding post-procedural care.

What are the potential savings from steering patients to lower-priced providers? a static analysis

OBJECTIVES

Healthcare payers are increasingly using price transparency and benefit design to encourage patients to choose lower-priced providers. We quantify potential savings from shifting patients to lower-priced providers. If there is limited price variation or if higher-priced providers command little market share, savings could be minimal.

STUDY DESIGN

Using 2013-2014 commercial claims for 697,381 enrollees in California, we characterized within-market price variation and the relationship between providers' market shares and relative prices for 3 nonemergent, shoppable outpatient services: laboratory tests, imaging services, and durable medical equipment (DME). In a stylized policy simulation that holds provider price and utilization constant, we computed potential savings if patients who visited providers with prices above the median price shifted to the median-priced provider in their geographic market for the same service.

METHODS

Observational analyses.

RESULTS

Of the service categories examined, laboratory tests had greatest within-market price variation (median coefficient of variation of 100% vs 87% for imaging services and 43% for DME). Roughly half of services (53%, 47%, and 54% for laboratory tests, imaging services, and DME, respectively) were billed by providers with prices above their market median. Shifting these patients to the median-priced provider in their markets could save 42%, 45%, and 15% of spending on laboratory tests, imaging services, and DME, respectively, together representing savings of 11% of total outpatient spending and 7% of the sum of inpatient and outpatient spending.

CONCLUSIONS

Steering patients from higher- to lower-priced providers within geographic markets in targeted service categories could generate substantial healthcare savings.

A chemiluminescent, magnetic particle-based immunoassay for the detection of hepatitis C virus core antigen in human serum or plasma

Hepatitis C virus (HCV) exposure in blood donors is determined serologically by the detection of anti-HCV antibodies in serum or plasma. However, a "window" period of 30-70 days after exposure exists where specific antibodies to HCV antigens are not detected. The use of nucleic acid testing for the detection of HCV RNA or antigen testing for the detection of HCV core protein have resulted in dramatic reductions in the pre-seroconversion window period. In this study, an automated HCV core antigen detection test was developed. This magnetic microparticle-based assay utilizes anti-HCV core monoclonal antibody to capture antigen present in human serum or plasma. Captured antigen is then detected using an anti-HCV core monoclonal antibody conjugated with a chemiluminescent compound. The specificity of this assay was established at 99% upon testing a population of normal volunteer blood donors. Sensitivity was determined by testing 16 commercially available HCV seroconversion panels representing genotypes 1a, 1b, 2b, and 3a. In each panel tested, HCV core antigen was detected prior to anti-HCV antibody, resulting in a reduction of the window period by greater than 23 days on average, and greater than 34 days on panels initially NAT negative. In addition, HCV core antigen was detected in >97% of HCV RNA positive/antibody negative specimens, exhibiting sensitivity nearly equivalent to nucleic acid testing in the pre-seroconversion window period for the panels examined.

Recently discovered blood-borne viruses

In recent years, molecular biology advances have enabled many investigators to discover a number of viruses that have been difficult to characterise by cell culture techniques. Two blood-borne viruses have been identified. These are GB virus C (GBV-C) and TT virus (TTV). GBV-C was discovered in 1995. It is a flavivirus-like enveloped particle measuring 50-100 nm in diameter with a density of 1.08-1.13 g/cm3. The genome of GBV-C is a single-stranded, positive strand ribonucleic acid of approximately 8600 nucleotides. The TTV was discovered in 1997. It is a circular single-stranded deoxyribonucleic acid virus, non-enveloped of approximately 3900 nucleotides. It has a density of 1.31-1.34 g/cm3 and a particle size of 30-50 nm. Both viruses are distributed widely throughout the world. Most GBV-C infections are asymptomatic, transient and self-limiting. To date, solid evidence for any association of TTV with disease has not been demonstrated.

Optimized PCR assay for the detection of TT virus

A polymerase chain reaction (PCR)-based procedure for the detection of TT virus DNA is described. In this method. total nucleic acid extracted from a small volume of serum or plasma is utilized as a template in PCR employing TT virus specific primers designed to highly conserved regions of the virus genome. Additional sensitivity is obtained by carrying out a second round of amplification. Reactions are analyzed by agarose gel electrophoresis, and samples having an ethidium bromide stainable fragment of the appropriate size in the first and/or second amplification are designated as positive. This protocol allows for the rapid and sensitive detection of TT virus in human plasma or serum.

Rapid detection of Hepatitis E virus RNA by reverse transcription-polymerase chain reaction using universal oligonucleotide primers

A rapid reverse transcription-polymerase chain reaction (RT-PCR) procedure for the detection of Hepatitis E virus (HEV) RNA in serum is described. Total nucleic acids are extracted from a small volume of human serum and reverse transcribed using random hexamers. An aliquot of cDNA is then utilized in nested PCR employing degenerate HEV consensus primers. These primers are designed to sequences conserved between the Burma, Mexico, and US HEV strains, generating amplicons within each of the three open reading frames. Reactions are analyzed by agarose gel electrophoresis and samples showing an ethidium bromide stained band of the appropriate size in the first and second amplification, or in the second amplification only, are designated as positive. This protocol allows for the rapid and sensitive detection of HEV infection in human serum.

Analyses of TT virus full-length genomic sequences

Since the identification of TT virus, only one full-length and two near full-length sequences representing a single subtype of the virus have been reported. In order to understand further the nature of the TT virus genome, nine of the most divergent TT virus sequences have been extended to full-length or near full-length. Phylogenetic analysis demonstrated that these sequences represent three distinct TT virus genotypes and two subtypes. A high degree of nucleotide sequence variability (approximately 30%) was observed across the genomes with several significantly more divergent regions. Three conserved ORFs were identified, none of which shared significant amino acid sequence identity to sequences present in public databases. Additionally, sequence motifs, such as those necessary for protein translation and for rolling circle replication, were found to be partially conserved between all TT virus isolates.

Prevalence of TT virus infection in US blood donors and populations at risk for acquiring parenterally transmitted viruses

Two overlapping sets of TT virus (TTV)-specific polymerase chain reaction primers were used to test for presence of TTV, which was found in approximately 10% of US volunteer blood donors, 13% of commercial blood donors, and 17% of intravenous drug abusers. The rate of TTV infection among US non-A, non-B, non-C, non-D, non-E hepatitis patients was only 2%. Among commercial blood donors and intravenous drug abusers, only 1%-3% of the TTV-positive individuals were coinfected with GB virus C (GBV-C), a parenterally transmitted virus. This suggests that GBV-C and TTV may have different routes of transmission. Comparison of the sensitivities of 2 TTV polymerase chain reaction (PCR) primer sets showed that the majority of samples were detected with only 1 of the 2 sets. Therefore, previous studies in which only a single PCR primer pair was used may have significantly underestimated the true prevalence of TTV.

Novel hepatitis E virus (HEV) isolates from Europe: evidence for additional genotypes of HEV

Hepatitis E infection is associated with areas in which hepatitis E virus (HEV) infection is endemic. Acute infections in industrialized nations are usually linked to travel to endemic areas. Recently, an acute hepatitis infection in a patient from the United States (US), with no recent foreign travel history, was linked to a novel strain of HEV. Although a few additional cases have been reported from patients who have not traveled to endemic areas, the source of these infections has not been determined. The objective of this study was to identify additional HEV isolates from patients with acute infection who had no recent history of travel to areas where HEV is considered endemic, and to determine the genetic relationship between these and other HEV isolates. Viral RNA was isolated from serum and polymerase chain reaction (PCR) was performed using consensus primers based on a number of HEV isolates. HEV sequence in open reading frame (ORF) 1 and ORF2 was identified in three patients from nonendemic areas, one from Italy and two from Greece. Comparative and phylogenetic analyses were performed. The Greek and Italian isolates were significantly divergent from two isolates from the US and isolates identified previously from HEV-endemic regions. The Italian isolate was distinct from the two Greek isolates. In addition, the two Greek isolates were significantly divergent from each other. Phylogenetic analysis indicated that the Italian and two Greek isolates represent three new genotypes of HEV, distinct from the Burmese, Mexican, and US genotypes.

Novel hepatitis E virus (HEV) isolates from Europe: evidence for additional genotypes of HEV

Hepatitis E infection is associated with areas in which hepatitis E virus (HEV) infection is endemic. Acute infections in industrialized nations are usually linked to travel to endemic areas. Recently, an acute hepatitis infection in a patient from the United States (US), with no recent foreign travel history, was linked to a novel strain of HEV. Although a few additional cases have been reported from patients who have not traveled to endemic areas, the source of these infections has not been determined. The objective of this study was to identify additional HEV isolates from patients with acute infection who had no recent history of travel to areas where HEV is considered endemic, and to determine the genetic relationship between these and other HEV isolates. Viral RNA was isolated from serum and polymerase chain reaction (PCR) was performed using consensus primers based on a number of HEV isolates. HEV sequence in open reading frame (ORF) 1 and ORF2 was identified in three patients from nonendemic areas, one from Italy and two from Greece. Comparative and phylogenetic analyses were performed. The Greek and Italian isolates were significantly divergent from two isolates from the US and isolates identified previously from HEV-endemic regions. The Italian isolate was distinct from the two Greek isolates. In addition, the two Greek isolates were significantly divergent from each other. Phylogenetic analysis indicated that the Italian and two Greek isolates represent three new genotypes of HEV, distinct from the Burmese, Mexican, and US genotypes.

A hepatitis E virus variant from the United States: molecular characterization and transmission in cynomolgus macaques

The partial sequence of a hepatitis E virus (HEV-US1) isolated from a patient in the United States (US), suffering from acute viral hepatitis with no known risk factors for acquiring HEV, has been reported. These sequences were significantly different from previously characterized HEV isolates, alluding to the existence of a distinct human variant. In this paper, we report the near full-length sequences of HEV-US1 and a second US isolate (HEV-US2). HEV-US2 was identified in a US patient suffering from acute viral hepatitis. These sequences verify the presence of a new HEV strain in North America and provide information as to the degree of variability between variants. The HEV-US nucleotide sequences are 92% identical to each other and only 74% identical to the Burmese and Mexican strains. Amino acid and phylogenetic analyses also demonstrate that the US isolates are genetically distinct, suggesting the presence of three genotypes of HEV. Serum from the second US patient induced hepatitis following inoculation into a cynomolgus macaque. Within 2-4 weeks, HEV-US2 RNA was detectable in both the serum and faecal material coinciding with elevated serum alanine transaminase levels. Infection resolved as antibody titres increased 8 weeks post-inoculation.

Isolation of a GB virus-related genome from a chimpanzee

Recently, two new flaviviruses, GB virus A (GBV-A) and GB virus B (GBV-B), were identified in the plasma of a tamarin infected with the hepatitis GB agent. A third virus, GB virus C (GBV-C), was subsequently identified in humans. In the current study, representational difference analysis (RDA) was used to search for a new virus in the serum of a chimpanzee that developed acute resolving hepatitis following inoculation with a pool of chimpanzee plasma. The plasma pool originated from serial passages of a human sample containing virus-like particles. Numerous cDNA clones were obtained that exhibited 62-80% identity with GBV-C. With the exception of the extreme 5' and 3' ends, the complete viral genome was sequenced, revealing a single large open reading frame encoding a 2833 amino acid polyprotein that contains two envelope proteins, two proteases, a helicase, and an RNA-dependent RNA polymerase. Phylogenetic analysis of the new virus indicates that it is closely related to GBV-C, yet still sufficiently divergent as to be placed in a separate group, tentatively labeled GB virus Ctroglodytes (GBV-Ctro). Numerous human samples were screened by reverse transcriptase-polymerase chain reaction (RT-PCR), but GBV-Ctro sequence was not detected. However, a second chimpanzee inoculated with the same plasma pool was shown to develop a GBV-Ctro infection. Although isolated from an Old World primate with hepatitis, the primary host of GBV-Ctro and any association with disease remains to be determined.

Predictors of GBV-C infection among patients referred for renal transplantation

The etiology of liver disease remains unknown in about 4 to 23% of dialysis patients and 10 to 16% of renal transplant recipients. A search for other causative agents of liver disease led to the discovery of the GB group of viruses. We studied the association between the presence of GB virus C (GBV-C) infection, known risk factors for parenterally-transmitted infections and history or laboratory evidence of liver disease among end-stage renal disease (ESRD) patients referred for renal transplantation to the New England Organ Bank, MA. Stored sera from patients on the renal transplantation waiting list between November 1986 and June 1990 were tested for antibody to hepatitis C virus (HCV). Sera were available in 1544 of 3243 (48%) patients, and anti-HCV was detected by ELISA3 in 287 (19%). All 287 anti-HCV positive patients formed the anti-HCV positive cohort and 286 randomly selected anti-HCV negative patients formed the anti-HCV negative cohort (573 patients overall). Additional sera were available for GBV-C RNA testing in 465 of 573 (81%) patients, and GBV-C RNA was detected by RT-PCR in 146. The overall extrapolated prevalence of serum GBV-C RNA was 29%. The prevalence of serum GBV-C RNa among anti-HCV positive patients (35%) was not significantly different from that among anti-HCV negative patients (29%; P = 0.22). In a univariate analysis, compared to patients without GBV-C RNA, patients with serum GBV-C RNA were younger [odds ratio (OR) 0.98 per year of age, P = 0.01], had a lower proportion of males (OR 0.64, P = 0.03), lower proportion of patients with diabetes mellitus (OR 0.44, P = 0.01), higher proportion of patients with a previous transplantation (OR 1.53, P = 0.04), longer duration of dialysis at the time of enrollment (OR 1.004 per month on dialysis, P = 0.03), and a higher proportion of patients with history of transfusions (OR 4.58, P = 0.01). Serum GBV-C RNA was not associated with a significantly increased OR for history of liver disease or non-A, non-B hepatitis, or elevated serum alanine aminotransferase levels. In a step-wise multivariate regression analysis, a younger age (OR 0.98 per year of age, P = 0.03), and history of blood transfusions (OR 3.89, P = 0.03) were associated with an increased OR for serum GBV-C RNA, while diabetes mellitus was associated with a decreased OR for GBV-C RNA (OR 0.47, P = 0.01). Anti-HCV was not a predictor of serum GBV-C RNA (OR 1.07, P = 0.77). The results of this study support the fact that GBV-C is a parenterally transmitted virus and shed light on the modes of transmission of GBV-C among ESRD patients. However, the association with liver disease remains to be established.

The sequence and phylogenetic analysis of a novel hepatitis E virus isolated from a patient with acute hepatitis reported in the United States

A variant of hepatitis E virus (HEV), designated HEV US-1, was identified in a hepatitis patient in the United States (US); the patient had no history of travel to areas where HEV is endemic. Nucleotide sequences were obtained from the 5' end of open reading frame (ORF) 1 (1418 nt), the 3' end of ORF1 (1359 nt), the entire ORF2 and ORF3 regions, and the 3'-untranslated region (2127 nt). The HEV US-1 strain is significantly divergent from other human HEV isolates with nucleotide identities ranging from 76.8 to 77.5%. Phylogenetic analyses indicate that HEV US-1 and a recently discovered HEV variant from swine may represent separate isolates of a new strain of HEV, significantly divergent from the Mexican and Burmese strains. Synthetic peptides derived from the carboxyl amino acids of ORF2 and ORF3 were shown to be useful for detecting exposure to HEV. In addition, IgM class antibodies directed against HEV US-1 synthetic peptides were detected in the US patient infected with HEV US-1, but were absent using synthetic peptides from the Burmese or Mexican strains of HEV. A preferential reactivity to HEV US-1 specific peptides has lead to the identification of a second isolate of this virus also from a patient with acute hepatitis from the US. The discovery of these HEV variants may be important in understanding the worldwide distribution of HEV infection.

Genomic analysis of two GB virus A variants isolated from captive monkeys

The recent isolation of GB viruses A and B from GB agent infected tamarins and their lack of involvement in human hepatitis has sparked interest in the origin of these viruses. Several healthy non-human primate species have been shown to harbour sequences 52-79% identical to the GBV-A 5' nontranslated region. In this paper we report the near genome length sequence of GBV-Amx 70047 and GBV-Atri 1122. These sequences support previous observations about the genomic organization of GBV-A and provide insight into the genomic variability within this virus genus. Although the GBV-A variant polyproteins possess many motifs conserved between other members of the Flaviviridae, they do not encode a basic core-like protein. Amino acid sequence comparisons and phylogenetic analysis demonstrate variability within the GBV-A genus similar to that observed between hepatitis C virus (HCV) types. However, genomic organization and disease association demonstrate a closer evolutionary relationship to GBV-C than to HCV.

GB virus C (GBV-C) infection in patients with chronic hepatitis C. Influence on liver disease and on hepatitis virus behaviour: effect of interferon alfa therapy

The aim of this study was to evaluate, in patients with chronic hepatitis C, 1) the prevalence and the epidemiological characteristics of GB virus C (GBV-C) infection, 2) the influence of GBV-C on hepatitis C virus (HCV) infection, 3) the pathogenicity of GBV-C in the absence of treatment and under interferon therapy, and 4) the effect of interferon alfa on GBV-C and HCV replications. One hundred fifteen patients with chronic hepatitis C were studied. Before treatment, they were tested for GBV-C RNA by PCR and GBV-C genotype was determined for positive samples. Pretreatment information was collected, including age, gender, source of HCV, estimated duration of HCV infection, alanine aminotransferase and gamma-glutamyl transpeptidase activities, cirrhosis and Knodell's score on liver biopsy, HCV genotype, HCV viral burden and anti-HCV core IgM antibodies. The genetic complexity of the hypervariable region 1 (HVR1) of HCV was studied by PCR-Single Strand Conformation Polymorphism. All patients were treated with 3 to 9 mega units of interferon alfa-2a three times per week for 3 to 6 months. The influence of GBV-C on the evolution of ALT and HCV replication during and after treatment was studied, and GBV-C and HCV RNA were monitored monthly by PCR during this period. Eighteen patients (16%) were GBV-C RNA-positive. Among 11 samples studied, GBV-C genotype 2a was present in 9 cases, 2b in one case and type 3 in one case. GBV-C RNA-positive patients were significantly younger than GBV-C RNA-negative ones (38.4 +/- 11.5 vs. 47.4 +/- 14.0, P = 0.012), a result independent of the route of transmission and the disease duration. No difference between GBV-C RNA-positive and -negative patients was found for other epidemiological parameters (e.g. gender, risk factor for parenteral viral infections, disease duration and HCV genotypes), or for the characteristics of HCV infection and related liver disease (e.g. HCV RNA level, genetic complexity of the HVR1, anti-HCV core IgM, alanine aminotransferase and gamma-glutamyl transpeptidase activities, cirrhosis and Knodell's score). GBV-C did not influence the rates of ALT normalization at months 3, 6 and 12 and of sustained hepatitis C virological response at month 12 of treatment follow-up. During treatment, GBV-C viremia became undetectable in 12 patients (67%) but relapse occurred after treatment withdrawal in all the nine patients with sufficient follow-up. In the remaining six patients (33%), GBV-C resisted interferon. Whatever the effect of interferon on GBV-C replication, the ALT levels correlated with the presence of HCV RNA. In conclusion, GBV-C infection is frequent in patients with chronic hepatitis C, who are mainly, but not exclusively, infected by GBV-C genotype 2a. GBV-C positive patients are significantly younger than GBV-C negative ones. GBV-C does not seem to affect HCV replication, liver disease and responses of HCV infection and liver disease to interferon therapy. GBV-C is sensitive to 3 mega units of interferon alfa administered three times per week in two-thirds of the patients, but relapse is constant with this dosage after treatment withdrawal.

Rapid detection of GB virus C RNA by reverse transcription-polymerase chain reaction (RT-PCR) using primers derived from the 5'nontranslated region

A simple reverse transcription-polymerase chain reaction (RT-PCR) procedure for the detection of GB virus C (GBV-C) RNA in serum or plasma is described. In this method, total nucleic acid, extracted from a small volume of human plasma, is reverse transcribed using random hexamers. An aliquot of cDNA is then utilized in PCR employing GBV-C specific primers designed to highly conserved regions of the 5'nontranslated region (NTR). For additional sensitivity, a second round of nested amplification is performed. Reactions are analyzed on an agarose gel and samples showing an ethidium bromide stained band of the appropriate size in the first and second amplification, or in the second amplification only, are designated to be positive. This protocol allows for the rapid and sensitive detection of GBV-C infection in human plasma or serum.

Identification of GB virus C variants by phylogenetic analysis of 5'-untranslated and coding region sequences

Phylogenetic analysis of 44 GB virus C (GBV-C) 5'-untranslated region (5'-UTR) sequences from 37 individuals suggested the presence of GBV-C genotypes (A. S. Muerhoff, J. N. Simons, T. P. Leary, J. C. Erker, M. L. Chalmers, T. J. Pilot-Matias, G. J. Dawson, S. M. Desai, and I. K. Mushahwar, J. Hepatol. 25:379-384, 1996) that correlated with geographic origin: type 1, 2a and 2b, and 3 isolates are found predominantly in West Africa, the United States and Europe, and Japan, respectively. We have extended our analysis to include 5'-UTR sequences from 129 globally distributed GBV-C isolates and sequences from the second envelope protein (E2) gene and nonstructural (NS) regions 3 and 5b from a subset of these isolates. Bootstrap analysis of a 157-nucleotide segment of the 5'-UTR from 129 sequences provided weak support for the existence of the four major groups of GBV-C isolates previously described, although phylogenetic analysis of a 374-nucleotide segment of the 5'-UTR from 83 isolates provided stronger support. Thus, the groups of GBV-C variants previously identified upon analysis of the entire 5'-UTR can be distinguished by analysis of the shorter, 374-nucleotide region from the 5'-UTR. In contrast, independent analysis of the E2, NS3, or NS5b region sequences does not identify groups of GBV-C variants that correlate with geographic origin. However, bootstrap analysis of these coding sequences, when linked to form colinear sequences, demonstrates that longer coding regions can produce GBV-C groupings that are similar to that determined from 5'-UTR sequence analysis. The inability to distinguish between GBV-C variants by using small segments of coding sequence suggests that the GBV-C genome is constrained. As a result of these constraints, there is a high degree of nucleotide and amino acid sequence conservation between isolates from widely separated geographic areas. Hence, substitutions at many nucleotide positions are not tolerated, so that substitutions at the positions which can change are saturated, thereby obscuring the evolutionary relationships.

The sequence and genomic organization of a GB virus A variant isolated from captive tamarins

Recently, gene fragments of several novel variants of GB virus A were isolated from the serum of distinct monkey species that had not been experimentally inoculated with an infectious agent. These variants appeared to be species-specific in that sequences isolated within a species were virtually identical, though sequences were strikingly different when compared between each species. In the present study, the nucleotide sequence of one of these variants, GBV-Alab, was extended to near-genome length. Similar to the other GB viruses, GBV-Alab appears to encode a single large polyprotein of 2967 amino acids that is post-translationally cleaved by cellular and viral proteases into the individual viral proteins. The structural proteins are found at the N-terminal end of the polyprotein, while the nonstructural proteins are found at the C teminus. Amino acid sequence comparisons of the large polyprotein demonstrate that GBV-Alab is 74% identical to GBV-A and 48% identical to GBV-C, sharing only marginal identity with GBV-B and HCV-1 at 27%. Examination of the GBV-Alab polyprotein reveals that structural motifs are conserved for a protease, a helicase and a replicase. Phylogenetic analysis of the polyprotein confirms previous results that GBV-Alab is a member of the Flaviviridae, distinct from GBV-B and HCV, though more closely related to GBV-A and GBV-C.

GB virus C E2 glycoprotein: expression in CHO cells, purification and characterization

A 315 amino acid recombinant segment of the GB virus C (GBV-C) E2 envelope glycoprotein (E2-315) was expressed and secreted from CHO cells. E2-315 was purified by affinity chromatography using a monoclonal antibody directed to a FLAG sequence genetically engineered onto the C terminus of the recombinant protein. The secreted protein had a molecular mass of 48-56 kDa and was shown to be N-glycosylated. Amino acid sequencing confirmed the expected N-terminal sequence. Purified E2-315 was used to develop an ELISA for detection of E2 antibodies in human sera. Antibodies to GBV-C E2 appeared to be directed toward conformational epitopes since human sera reactivity was detected in ELISA using native E2-315, but it was extremely weak or non-existent with denatured E2 protein. The use of an ELISA which can detect human GBV-C E2 antibodies will be important in further understanding of the clinical significance and epidemiology of GBV-C.

Impact of pretransplantation GB virus C infection on the outcome of renal transplantation

Among renal transplant recipients with posttransplantation liver disease, the etiology remains unknown in 10 to 16% of patients. The discovery of yet another parenterally transmitted hepatitis virus, GB virus C (GBV-C), has opened avenues to study the prevalence and risk factors for GBV-C infection among patients undergoing renal transplantation and its impact on posttransplantation clinical outcomes. A cohort of 103 randomly selected recipients of kidneys were examined from anti-hepatitis C virus (HCV)-negative donors between 1986 and 1990. Pretransplantation sera were available in 99 of 103 (96%) recipients and were tested for anti-HCV, using a second-generation ELISA, and for GBV-C RNA by reverse transcription PCR. Pretransplantation GBV-C RNA was present in 18 of 99 (18%, 95% confidence interval [CI], 17.2 to 18.8%) recipients. GBV-C RNA was present in 5 of 22 (23%) anti-HCV-positive recipients compared with 13 of 77 (17%) anti-HCV-negative recipients (P = 0.53). The median number of pretransplantation blood transfusion among recipients with GBV-C RNA before transplantation was significantly higher than among recipients without GBV-C RNA (10 versus 7, P = 0.05). Posttransplantation liver disease and non-A, non-B hepatitis (NANBH) was observed in 35 and 18%, respectively, of GBV-C RNA-positive recipients compared with 28 and 10%, respectively, of GBV-C RNA-negative recipients. Using Cox regression analysis, the relative risk (RR) of posttransplantation liver disease among recipients with GBV-C RNA before transplantation was 1.37 (95% CI, 0.55 to 3.41), and posttransplantation NANBH was 2.09 (95% CI, 0.64 to 6.79). The RR of graft loss and death were not increased (0.88 and 0.92, respectively). When adjusted for pretransplantation anti-HCV, the RR of posttransplantation liver disease, NANBH, graft loss, and death did not change appreciably. In summary, although a higher risk of posttransplantation liver disease was observed among recipients with pretransplantation GBV-C infection, the analyses presented here do not allow for a precise estimate of this risk.

GB hepatitis agent in cadaver organ donors and their recipients

BACKGROUND

The cloning of yet another hepatitis virus, GB virus-C (GBV-C), has provided the opportunity to study the prevalence, and clinical and laboratory characteristics, associated with GBV-C infection among cadaver organ donors and recipients of organs from infected donors.

METHODS

Stored sera from a cohort of cadaver organ donors from eight organ procurement organizations, representing different geographic regions of the United States previously screened for hepatitis C virus (HCV) infection, were tested for GBV-C RNA by polymerase chain reaction using degenerate primers derived from the NS3 helicase and 5'-untranslated regions of the GBV-C genome. Pre- and posttransplantation clinical data, and prevalence of GBV-C RNA among recipients of organs from GBV-C RNA-positive and -negative donors, were studied at one of the organ procurement organizations.

RESULTS

Twenty-one of 76 (27.6%) anti-HCV ELISA1-positive donors tested positive for GBV-C RNA compared with 6 of 82 (7.3%) ELISA1-negative donors (P=0.001). The prevalence of GBV-C RNA, extrapolated to all cadaver organ donors, was 8.3% (95% confidence interval [CI]: 5.6-11.1%) and was higher than the prevalence of HCV RNA (2.4%). Among ELISA1-positive donors, GBV-C RNA was present in 13 of 35 (37%) donors with HCV RNA, compared with 8 of 41 (20%) donors without HCV RNA (odds ratio [OR]=2.44, P=0.09). Blood alcohol level of more than 100 mg/dl (OR=9.43, P=0.05) and a positive anti-HCV ELISA2 (OR=4.58, P=0.001) were significantly associated with GBV-C infection. In addition, there was a trend toward an association between history of drug abuse (OR=5.23, P=0.06) and younger age (OR=0.97/year, P=0.06) with GBV-C infection. Organs from four GBVC-positive donors and 47 GBV-C-negative donors procured by the New England Organ Bank (Newton, MA) were transplanted into 6 and 79 recipients, respectively. Among recipients of organs from GBV-C RNA. positive donors, the posttransplantation prevalence of GBV-C RNA (25%) was not significantly higher than among recipients of organs from GBV-C RNA-negative donors (23%). Among recipients in whom both pre- and posttransplantation sera were available, one of three (33%) recipients of kidneys from GBV-C RNA-positive donors acquired GBV-C RNA after transplantation, compared with 4 of 40 (10%) recipients of kidneys from GBV-C RNA-negative donors. After a median follow up of 6 years, the posttransplantation prevalence of liver disease, and graft and patient survival, were not significantly different between recipients of organs from GBV-C RNA-positive and -negative donors.

CONCLUSIONS

Although GBV-C could be transmitted by organ transplantation, the results of this study preclude definitive conclusions. Further studies are required to determine the risk of transmission of GBV-C by organ transplantation and its role in posttransplantation liver disease.

Sequence and genomic organization of GBV-C: a novel member of the flaviviridae associated with human non-A-E hepatitis

Recently, sequences from a novel virus, termed GB virus C (GBV-C), were identified in serum from several patients with cryptogenic hepatitis. In the present study, the nucleotide sequence of this virus has been extended to near-genome length. GBV-C encodes a putative single large polyprotein in which the structural proteins are positioned at the N-terminal end, with the non-structural proteins located at the C-terminal end. Amino acid sequence analysis of this large polyprotein reveals the presence of protease, helicase, and replicase motifs. Sequence alignments of the polyprotein followed by phylogenetic analyses suggest that GBV-C is a member of the Flaviviridae, most closely related to the recently described GB virus A.

Species-specific variants of GB virus A in captive monkeys

Sequences from the putative 5' nontranslated region of GB virus A were isolated from mystax, owl monkeys, and tamarins. Though sequences of isolates from each animal species are virtually identical at the nucleotide level (95%), isolates from different species are dramatically different (52 to 79% identical) and genetically cluster on this basis.

Expression of the GB virus C E2 glycoprotein using the Semliki Forest virus vector system and its utility as a serologic marker

A 336-amino-acid segment of the GB virus C second envelope protein (E2) has been produced in BHK-21 cells using the Semliki Forest virus vector system. Secretion of this protein was facilitated by deletion of a hydrophobic region at the C-terminus that may represent the membrane anchoring domain. The E2 protein recovered from the culture supernatant exhibited a molecular mass of approximately 52 kDa, with the increase in size relative to the polyprotein backbone being contributed by N-linked glycosylation. A radioimmunoprecipitation assay using GBV-C E2 was developed to test for the presence of antibodies against this protein in human sera. The prevalence of antibodies to E2 was high among injection drug users and other individuals at risk for acquiring parenterally transmitted agents. There was a much higher percentage of anti-E2 seropositivity in GBV-C RT-PCR negative compared to GBV-C RT-PCR positive samples from these populations. In addition, serial samples from patients transfused with blood containing GBV-C showed seroconversion to anti-E2 positivity and loss of GBV-C viremia as measured by RT-PCR within 11 months of transfusion in five of seven individuals. Thus, this system provided a rapid means to identify GBV-C E2 as a useful antigen for the study of GBV-C exposure.

Molecular cloning and characterization of a GB virus C isolate from a patient with non-A-E hepatitis

Recently, the isolation of a novel virus, GB virus C (GBV-C), associated with cryptogenic hepatitis has been reported. Following the molecular cloning of this virus genome, it became apparent that the genomic sequence did not encode a protein resembling a nucleocapsid or core-like protein similar to those observed in other flaviviruses, pestiviruses, hepatitis C virus (HCV) and GB virus B. Similar findings were subsequently observed in the cloning of two viral genomes representing isolates of GBV-C, namely hepatitis G virus (HGV). To verify the presence or absence of a viral nucleocapsid protein, identify conserved protein motifs and determine the overall genomic variability, an additional virus isolate has been characterized. Here we report the full-length genomic sequence of GBV-C(EA), isolated from an East African suffering from acute non-A-E hepatitis. GBV-C(EA) was compared with the prototype West African isolate (GBV-C) and the two HGV isolates from the United States. The analyses demonstrate several characteristics of these novel viruses. (1) The degree of variability within the 5' nontranslated region (NTR) approximates that observed between HCV isolates. (2) The nucleotide sequence of the coding region and the 3' NTR is highly conserved between these isolates, in contrast to the extensive variability observed between HCV isolates from distinct geographical locations. (3) There is a high degree of amino acid conservation across the precursor polyproteins of these isolates; most striking is the lack of 'hypervariable' regions within the envelope proteins. (4) There appears to be no nucleocapsid protein near the amino terminus of the GBV-C/HGV polyproteins.

Identification of conserved nucleotide sequences within the GB virus C 5'-untranslated region: design of PCR primers for detection of viral RNA

Recently, the discovery of a new human RNA virus, GB virus C (GBV-C), was reported. GBV-C was isolated from the serum of a West African individual using degenerate oligonucleotide PCR primers designed from a consensus sequence of the NS3 helicase genes of hepatitis C virus (HCV), GBV-A, and GBV-B. Seven other individuals were shown to be infected with GBV-C via RT-PCR using these primers. Subsequently, degenerate PCR primers based upon a consensus sequence of the eight original isolates were designed. These primers were shown to be superior to the original set. However, since they were derived from a region of the viral genome exhibiting up to 17% nucleotide sequence divergence, mismatch between the primers and template may result in an underestimation of the true GBV-C prevalence. To overcome this potential problem, we obtained the sequences at the 5'-untranslated region (UTR) of the GBV-C genome from 35 infected individuals and identified regions of high sequence conservation among the isolates. We describe the design and testing of PCR primers derived from conserved sequences within the 5'-UTR of the GBV-C genome. These primers were shown to be as effective as the helicase-derived primers in detecting GBV-C RNA in human sera.

Improved management of abdominal undescended testicular tumors with bulky confluent retroperitoneal nodal metastases

PURPOSE

Germ cell tumors of the abdominal undescended testis associated with confluent bulky retroperitoneal metastases are challenging problems. We report the results of neoadjuvant cisplatin based chemotherapy after diagnosis of germ cell tumors by fine needle aspiration cytology of the abdominal testicular mass. After chemotherapy all patients underwent abdominal orchiectomy with retroperitoneal lymph node dissection for residual nonseminomatous germ cell tumors or radiotherapy for pure seminomas.

MATERIALS AND METHODS

Between 1980 and 1991, 57 of 425 patients (13.4%) with germ cell tumors of the testicle had malignancy in an undescended testis, while 39 (68.4%) had tumor in an abdominal testis with confluent bulky metastasis. Metastatic evaluation included tumor marker studies, chest x-ray and computerized tomography of the abdomen. Among the tumors 29 (74.4%) were large volume seminomas (stages IIc, III and IV) and 10 (25.6%) were large volume nonseminomas. All 39 patients received 3 cycles of induction chemotherapy, and orchiectomy was deferred until its completion (14 received vinblastine, actinomycin D and bleomycin-6, and 25 received bleomycin, etoposide and cisplatin). After evaluation of response, the testis was excised. Overall followup was 2 to 12 years (median 4.6).

RESULTS

Of 29 seminomas 14 (48.3%) showed a complete and 11 (37.9%) showed a partial response. The latter tumors were treated subsequently with radiotherapy. Four patients with progressive disease died, for an actuarial survival rate of 86%. Of the 10 patients with nonseminomatous germ cell tumor 2 (20%) had a complete response and 4 had a partial response. All patients with a partial response underwent retroperitoneal lymph node dissection. Overall, 4 patients with progression and 2 with a partial response died, for an actuarial survival rate of 39%. Of 39 post-chemotherapy orchiectomy specimens 24 (61.5%) showed viable tumor cells. Furthermore, 16 of 39 patients (41%) had additional ilioinguinal metastases requiring adjuvant radiotherapy or surgery.

CONCLUSIONS

Surgical removal of the primary tumor in an undescended testis with bulky metastasis is difficult. We believe that initial chemotherapy followed by 1-stage surgical removal of the primary and residual metastasis is a favorable option to improve compliance and decrease the incidence of loss to followup. Atypically altered ilioinguinal metastases may necessitate a change in radiotherapy ports and/or retroperitoneal lymph node dissection boundaries. The significantly poorer survival with nonseminomatous germ cell tumor could be due to the fact that 50% of the lesions were stage IV at presentation. However, multivariate analysis showed only tumor histology to be the significant parameter and not initial stage at presentation.

Identification of antigenic regions in the GB hepatitis viruses GBV-A, GBV-B, and GBV-C

The genomes of two novel members of the Flaviviridae associated with GB agent hepatitis (GB viruses A and B) were cloned and sequenced recently. The genome of a third novel virus (GB virus C), related to but distinct from GB viruses A and B, has also been identified and characterized. Overlapping clones encompassing the large open reading frames of these three viruses have been expressed in E. coli as CTP:CMP-3-deoxy-D-manno-octulosonate cytidylyltransferase (CKS) fusion proteins. Bacterial lysates were subjected to Western blot analyses using sera from GB agent-infected tamarins and human sera from various individuals with or "at risk" for non-A, non-B, non-C, non-D, non-E hepatitis. Antigenic regions were identified in the putative NS3, NS4, and NS5 proteins from all three viruses. An antigenic region was also identified in the putative core protein of GB virus B. Many of the clones identified originally as encoding antigenic proteins were quite large. To map these regions more narrowly, smaller overlapping clones were generated by polymerase chain reaction (PCR), expressed as recombinant CKS fusion proteins and tested by Western blot. Additionally, a lambda gt11 expression library was generated from infectious tamarin sera and immunoscreened. These studies have identified at least three epitopes in GB virus A, five epitopes in GB virus B and four epitopes in GB virus C.

Sequence heterogeneity within the 5'-terminal region of the hepatitis GB virus C genome and evidence for genotypes

BACKGROUND

GB virus C is a positive-strand RNA virus that is associated with hepatitis in humans. GB virus C bears some resemblance to hepatitis C virus in its genomic sequence and organization. However, unlike hepatitis C virus, an open reading frame possessing a complete core protein was not identified in the original isolate.

METHODS

To verify the sequence at the 5'-end of the GB virus C genome, we amplified approximately 600 nucleotides from this region from 35 globally distributed individuals. The nucleotide sequences were translated in all possible reading frames and then examined for conserved motifs indicative of nucleocapsid or core-like peptides.

RESULTS

Forty-two unique GB virus C sequences were obtained from the 35 individuals. The deduced amino acid sequences upstream of the putative E1 gene from each isolate varied in length and composition, such that a conserved core-like sequence was not apparent. No core-like sequences were evident in the other reading frames. There was, however, a single methionine codon held in common among all isolates, although it was located very near the presumed amino-terminus of the putative E1 protein. Further analysis of the sequences for their evolutionary relatedness demonstrated the existence of five GB virus C subtypes that demonstrated a significant correlation with geographic distribution.

CONCLUSIONS

GB virus C differs from hepatitis C virus and GB virus B in that it does not encode a nucleocapsid or core protein. The existence of GB virus C subtypes emphasizes the importance of investigating the correlation between infecting subtype and the severity of liver disease and/or responsiveness to treatment of GB virus C-associated hepatitis.

Translation initiation in GB viruses A and C: evidence for internal ribosome entry and implications for genome organization

GB viruses A and C (GBV-A and GBV-C) are two recently described RNA viruses which appear to be members of the Flaviviridae. Although both viruses appear to contain long 5' nontranslated regions, the sites of polyprotein initiation and the presence of core-like proteins remain to be determined. Translation studies were undertaken to determine the mechanism and sites of polyprotein initiation in GBV-A and GBV-C. Rabbit reticulocyte lysates programmed with monocistronic RNAs containing 5' ends of GBV-A or GBV-C fused in-frame with the chloramphenicol acetyltransferase (CAT) open reading frame generated GBV-CAT fusion proteins in vitro. Site-specific mutagenesis and N-terminal sequencing located the sites of translation initiation immediately upstream of the putative signal sequence for the GBV E1 envelope glycoproteins. Efficient translation of the monocistronic GBV-CAT RNAs required the inclusion of GBV coding sequences. This, coupled with the presence of at least 523 nucleotides of 5' nontranslated RNA containing multiple AUG codons, suggests that translation initiation of these RNAs did not utilize a ribosome scanning mechanism. Translation of bicistronic RNAs containing 5' nontranslated sequences within the intercistronic space was consistent with the presence of a weakly active internal ribosome entry site in both GBV-A and GBV-C. Secondary structure predictions indicate that the 5' ends of these viruses assume similar complex structures distinct from those identified in the internal ribosome entry site-containing picornaviruses, pestiviruses, and hepatitis C viruses. The data indicate that GBV-A and GBV-C are unique members of the Flaviviridae that do not contain core-like proteins at the N termini of their putative polyproteins.

Identification of antigenic regions in the GB hepatitis viruses GBV-A, GBV-B, and GBV-C

The genomes of two novel members of the Flaviviridae associated with GB agent hepatitis (GB viruses A and B) were cloned and sequenced recently. The genome of a third novel virus (GB virus C), related to but distinct from GB viruses A and B, has also been identified and characterized. Overlapping clones encompassing the large open reading frames of these three viruses have been expressed in E. coli as CTP:CMP-3-deoxy-D-manno-octulosonate cytidylyltransferase (CKS) fusion proteins. Bacterial lysates were subjected to Western blot analyses using sera from GB agent-infected tamarins and human sera from various individuals with or "at risk" for non-A, non-B, non-C, non-D, non-E hepatitis. Antigenic regions were identified in the putative NS3, NS4, and NS5 proteins from all three viruses. An antigenic region was also identified in the putative core protein of GB virus B. Many of the clones identified originally as encoding antigenic proteins were quite large. To map these regions more narrowly, smaller overlapping clones were generated by polymerase chain reaction (PCR), expressed as recombinant CKS fusion proteins and tested by Western blot. Additionally, a lambda gt11 expression library was generated from infectious tamarin sera and immunoscreened. These studies have identified at least three epitopes in GB virus A, five epitopes in GB virus B and four epitopes in GB virus C.

Consensus oligonucleotide primers for the detection of GB virus C in human cryptogenic hepatitis

Recently, sequences from a putative member of the Flaviviridae, GB virus C (GBV-C), were isolated from the serum of patients with cryptogenic hepatitis. These sequences were 83-99% identical at the nucleotide level. Because of the divergence between these GBV-C isolates, it is likely that the PCR-based detection assay yields false negatives, underestimating dramatically the true prevalence of GBV-C in human hepatitis. We report the design of a GBV-C consensus oligonucleotide primer pair that is superior to those originally described. These primers identify GBV-C sequences in cases of cryptogenic hepatitis, allowing a better estimation of the prevalence of this virus in human populations.