Research/Articles

Rare Birds in North America: Acute Hepatitis C Cohorts

December 8, 2008

In this issue of GASTROENTEROLOGY, the Comment from the Editor highlights eight cohorts of patients with acute hepatitis C virus (HCV) infection and the dedicated investigators who are tracking these rarely identified patients in variety of unusual settings — collectively identifying 643 patients since 1996 as summarized in table1.html

The identification, enrollment, prospective monitoring and treatment of patients with acute HCV infections require enormous collaborative efforts and networking among individuals and institutions in addition to multiple sources of research funding. Acute hepatitis C infection provides a critical window of opportunity to understand the early and dynamic host-virus interactions that define the outcome of HCV infection, an opportunity that is lost once HCV persistence or resolution is firmly established. These cohorts continue to provide valuable insights about the natural history, outcome, therapy and immune pathogenesis of acute hepatitis C infection in various populations while offering important collaborative opportunities.

Acute Hepatitis in Injection Drug Users

Baltimore Cohort (1996–Present), The Johns Hopkins University Principal Investigators (PIs): Andrea L. Cox, David L. Thomas

Since 1996, the Baltimore cohort has identified acute hepatitis C among active injection drug users (IDUs) through community outreach and street-based recruitment in neighborhoods frequented by high-risk youths (mostly 19 – 35 years old). Participants are enrolled if they are active IDUs and test negative for anti-HCV antibodies. They receive counseling before and after testing and are referred to drug treatment and needle exchange programs. The protocol is designed for monthly follow-up with testing for HCV RNA as well as anti-HCV. Therefore, subjects are identified without regard to the presence of symptoms.

The cohort investigators also follow a smaller number of subjects who were identified through common source outbreaks or on the basis of symptoms. Subjects with acute HCV infection are educated about the potential benefits of early therapy and referred for evaluation for treatment. Subjects are also educated about the risks of reinfection and cleared subjects are screened via RNA testing for reinfection. Acutely infected subjects are counseled regarding the benefits of therapy and referred for comprehensive evaluation and treatment.

This cohort has provided significant new insights on epidemiology and immune pathogenesis of acute hepatitis C:

HCV transmission between IDUs as older drug users show new users how to inject.1

The induction of HCV-specific CD8+ T-cell responses in most patients with acute hepatitis C and their decline with progression to chronicity without development of new responses.2

The characteristics of humoral immune response in acute HCV infection (delayed, low in titer and restricted primarily to the immunoglobulin [Ig]G1 subclass3).

Mechanisms of HCV persistence whereby sequence evolution contributes to viral escape from CD8+ T-cell responses and optimization of replicative capacity.4,5

High level expression of an inhibitory molecule on HCV-specific CD8+ T cells with progression to chronicity in the absence of escape.6

The Baltimore cohort study has been funded by U19 AI040035.

San Francisco Cohort
(2000–Present), UFO Acute HCV Study
PI: Kimberly Page, University of California SanFrancisco; Co-Investigators: Judith Hahn, Paula Lum, Stewart Cooper, Eric Delwart and Michael Busch

In San Francisco, prospective studies of HCV in young (less than30 years old) active IDUs have been underway since January 2000. Young IDUs were recruited in three waves and followed prospectively in “The UFO Study.” Details of this cohort were previously published7 and subsequent UFO Study participants were recruited in 2003–2004, and again in 2006 using the same methodology.

Participants found to have new and acute HCV infections (based on quarterly anti-HCV assays and nucleic acid amplification testing [NAT]) were followed prospectively in the “UFO Acute HCV” study cohort to track infection outcome (clearance or persistent infection), predictors of outcome and treatment feasibility.

Each month, UFO Acute HCV participants were interviewed and blood samples were collected to (1) quantify HCV (anti-HCV and HCV RNA) and alanine aminotransferase (ALT) levels, (2) assess immunologic responses, (3) perform virologic analyses, (4) determine treatment candidacy, and (5) bank specimens.

Referrals to care and assessments for HCV treatment were conducted in conjunction with a network of community-based providers. Acute HCV infection was classified as either a baseline incident acute infection (anti-HCV-negative but HCV RNA positive by NAT) or a prospective incident acute infection (initially HCV-negative by antibody and RNA testing but with confirmed positive HCV infection on follow-up). Viral clearance was defined as two consecutive serum-negative HCV RNA tests (by NAT) after confirmed acute or incident infection.

A total of 135 participants with acute or incident HCV have been identified; 95 (70.4 percent) have been studied longitudinally. Spontaneous HCV clearance was documented in 20 (21.1 percent); 68 (71.6 percent) showed persistent viremia and the remaining sevent (7.4 percent) could not be classified. Ongoing studies are assessing immunologic correlates of viral clearance, reinfection, infectivity and transmission dynamics between injecting partners and acute HCV treatment. The UFO Acute HCV Study is funded by the National Institutes of Health (NIDA 2-R01 DA016017). Dr Page has also received funding from NIAID (U19 AI040034).

Montreal Cohort (2005–Present), Centre de Recherche du CentreHospitalier de l’Université de Montréal
PIs: Julie Bruneau, NaglaaH. Shoukry;Co-Investigators: Mark Daniel, Marc Bilodeau

This cohort includes acute HCV cases identified in the Saint-Luc Cohort study (established in 1998 to follow IDUs in Montreal) and through partnership with methadone maintenance clinics and needle exchange programs in the Montreal area.

Since January 2005, participants at high risk for HCV acquisition, defined as those who share injection material or have an HCV-positive partner, are examined every three months. At each visit, participants are tested for HCV RNA and baseline plasma and peripheral blood mononuclear cell samples are collected. Between 2005 and 2008, 60 cases of acute hepatitis C were identified, defined by a positive anti-HCV and/or HCV RNA test after a negative test within the last six months. The cohort is mostly Caucasian, with a median age of 33, and is 58 percent genotype 3a, 31 percent genotype 1a and 1b, and 11 percent other genotypes.

Acute HCV patients are then followed monthly for 1.5 years. All patients who test positive for HCV RNA at 12 weeks are offered standard-of-care therapy through the Quebec Universal Health Care system and followed by a multidisciplinary team of clinicians, nurses and social workers in the outpatient clinic of the Addiction Medicine Division of the Centre Hospitalier de l’Université de Montréal.

Based on data from this cohort, researchers hope to understand correlates of the innate and adaptive immune responses to the outcome of HCV during the acute phase and early interferon therapy.8 In addition, researchers would hope to understand the impact of acute HCV infection and antiviral treatment on the behaviors and quality of life of active IDUs who have access to IDU-targeted health services.9

The work with this cohort was supported by grants from the Canadian Institutes for Health Research (CIHR) (MOP-74524, MOP-74581, MOP-84451), Fonds de la Recherche en Santé du Quebec (FRSQ) (FRSQ-12428), and the FRSQ-AIDS and Infectious Disease Network (SIDA-MI).

Acute Hepatitis Identified in Diverse

Risk Groups Boston/New England Cohort (1998–Present), the Massachusetts General Hospital Group PI: Georg Lauer, Arthur Kim

This cohort includes 150 patients primarily in the Boston/New England area acutely infected with HCV, identified through partnerships with the Massachusetts Department of Public Health, Massachusetts Department of Corrections and local physicians from multiple area hospitals. The majority of individuals report IDU as their primary risk factor, within the context of a rise of HCV prevalence in Massachusetts among youth-related to heroin use.

Initially, most subjects were identified based on symptoms, but a recent risk factor-based screening program for inmates entering the Massachusetts correctional system has increased the number of cases in the cohort, adding a substantial number of nonsymptomatic cases.

All patients are referred for comprehensive evaluation and treatment and more than 50 individuals have been treated. Patients are recruited to participate in translational studies regarding the early immunopathogenesis of disease as well as studies on viral evolution. This local cohort is complemented by a cohort of more than 70 subjects with acute HCV infection from Rio de Janeiro. These patients are all symptomatic, have acquired HCV through routes other than drug use, and have a spontaneous clearance rate of greater than50 percent.

Studies in this cohort produced several important scientific findings, including the first description of a successful early immune response against HCV.10 Other observations include:

The first observation of HCV escapes from CD8+ T-cell response in acute hepatitis C11.

A longitudinal analysis of full-length viral sequences regarding the mechanisms underlying the rate of viral evolution.12

The first direct ex vivo analysis of human virus-specific CD4+ T cells using class II tetramer Technology.13

An understanding of the dynamics of cell-mediated immunity during interferon-based therapies.14

The cohort has also sparked numerous collaborations with other groups worldwide.15,16 Work with this cohort has been funded by U19AI066345, K23AI054379, R01AI031563 and R01AI067926.

Denver Cohort

(2002–Present), University of Colorado Health Sciences University (Multicenter Study of Acute HCV in Community Settings and Academic Medical Centers)
PI: Hugo R. Rosen

This cohort has prospectively followed 81 patients with acute HCV infection from six cities in the United States (Portland, Seattle, Los Angeles, Memphis, Pittsburgh and Denver) identified through partnerships with health departments, needle exchange programs, plasmapheresis and blood centers as well as academic university practices. All individuals are counseled about risks of transmission, disease progression and treatment options.

The definition of acute hepatitis C and the demographic features of this cohort17 include:

A positive anti-HCV or HCV RNA test from a participant with a documented negative anti-HCV result within the past year.

A positive anti-HCV test from a participant with clinical hepatitis, detectable serum HCV RNA, an ALT greater than 10 times the upper limit of normal and negative results of tests for HBsAg and anti-HAV IgM.

By direct sequence analysis.

Diagnoses of acute hepatitis C were made after patients sought medical attention for symptoms, including nausea, anorexia, abdominal pain, malaise, fever and jaundice. Diagnoses were made by physicians specializing in hepatology or infectious diseases after evaluation of the patient’s clinical presentation and laboratory data. Both the presence of symptoms and female gender increase the likelihood of spontaneous recovery.

Studies of this cohort focus on:

Understanding the mechanisms governing cytotoxic T-cell escape.18

The importance of CD4+ T-cell help.19

Characterization of T-cell thresholds associated with recovery.19

The suppressive function of regulatory T cells in the early stages of infection.2

Dysregulation of interleukin-7Ra and persistence.21

The innate immune response, particularly of natural killer and natural T cells.22

Collaborations have been established with the Massachusetts General Hospital/ Broad Institute and The Johns Hopkins University groups to address novel questions utilizing this rare population of individuals. Work with this cohort has been funded by NIH RO1 DK60590.

Acute Hepatitis

Identified in Clinics and Hospitals
Atlanta Cohort (2004–Current), Emory University
PIs: Arash Grakoui, Hank Radziewicz, Co-Investigator: Kimberly Workowski

This cohort, initiated in 2004, comprises eight patients (six male and female female) acutely infected with HCV. The goal is to study immune mechanisms of HCV persistence, with a focus on adaptive T-cell immunity.

All patients were enrolled in Atlanta from either the Emory/Crawford Long Hospital/Clinics or from Grady Hospital/Clinics. Patients were initially identified based on elevated ALT levels and recognition by the medical provider of the possibility for acute HCV infection.

Risk factors included sexual transmission for six patients and IDU for two patients. Four of the patients are HIV positive. The community clinician or individual physician caring for the patient dictates treatment practices. To date, three patients completed combination therapy with pegylated interferon and ribavirin with sustained viral responses. One patient is currently on treatment; two others will receive treatment if viremia persists and one has refused therapy.

Acute HCV infection is defined by:

A positive HCV antibody test with a negative HCV antibody test within the past year

Hepatitis with concomitant HCV viremia

If a previous HCV antibody test had not been performed (or negative antibody test performed more than one year prior) and the patient presents with positive anti- HCV results

A syndrome of clinical hepatitis with an identified risk factor encounter for HCV (without another identified source for hepatitis) and HCV viremia

In this cohort, the researchers study T-cell functional deficits and the role of coinhibitory receptors such as PD-1 in regulating HCV-specific immune responses.23 Clinicians at the Atlanta VA collaborate in research to better understand the immune response to HCV and host determinants of infection outcome.

We acknowledge the support from the Grand Challenges in Global Health Initiative, EVC/CFAR Flow Cytometry Core P30 AI050409, Cancer Research Institute Investigator Award (AG), the Yerkes Research Center Base Grant RR-00165, and the Public Health Service [K08 AI072191 (HR), AI070101 (AG)].

Philadelphia Cohort
(1999–Present), University of Pennsylvania and Philadelphia VA Medical Center PI: Kyong-Mi Chang; Co-Investigator: David E.Kaplan

This cohort was established in 1999 using a referral network through various gastrointestinal (GI)/Hepatology, Infectious Disease and Primary Care clinics within the Hospital of University of Pennsylvania as well as the Primary Care, Addiction Recovery Unit, GI and ID Clinics at the Philadelphia VA Medical Center (PVAMC). Important clinical collaborators include K. Rajender Reddy (the Director of Hepatology at Penn) and Frederick A Nunes at Pennsylvania Hospital. Ayse Aytaman (the Chief of GI at the Brooklyn VA Medical Center) provides same-day blood samples from New York City.

Among 36 patients who met the criteria for acute hepatitis C, 30 have defined outcomes: six spontaneously resolved; three became chronically infected without therapy; 15 were treated (10 have achieved a sustained viral response). Investigators of the New York Mount Sinai Cohort collaborate in research.

Acute hepatitis C is diagnosed by a combination of clinical and serologic findings, including documented HCV seroconversion and/or spontaneous viremic fluctuations in patients with recent increases in liver enzymes without other causes of liver diseases as recently described.24 Patients are asked a series of questions to identify the potential source, timing and circumstance of HCV inoculation. With patient’s consent, relevant clinical laboratory measures are communicated to the patient and the primary hepatologist for clinical decisions — to be made at the discretion of each patient’s primary clinical provider with the patient. Active follow-up is maintained by the research coordinator. Blood samples are also collected to monitor the clinical and virologic course as well as immunologic parameters (particularly the adaptive immune response). Studies of this cohort have resulted in a number of observations regarding the relevance of antiviral effector and regulatory T-cell as well as neutralizing antibody, responses in patients with acute hepatitis C.24,25 Moreover, studies are examining the relevance of immune inhibitory or costimulatory molecules in HCV immune pathogenesis.26

The work with this cohort has been funded by the National Institutes of Health (NIAID, RO-1 AI47519) and the WW Smith Charitable Foundation.

Acute Hepatitis C in HIV-Infected Patients

New York Mount Sinai Cohort (2006–Current), Mount Sinai School of Medicine
PI: Daniel Fierer, Andrea Branch

This dynamic cohort was established in 2006 in response to the current HCV outbreak in New York City. It includes 35 subjects with acute HCV infection. Most are HIV-infected men who have sex with men (median age, 41).

Acute HCV infection was defined using three criteria in combination: seroconversion, marked increases in ALT levels, and greater than 1 log10 fluctuations in HCV viral load. The majority of infections were likely sexually acquired, although percutaneous exposures were reported by some subjects.

A detailed risk factor questionnaire is administered at the initial visit and blood samples are collected for peripheral blood mononuclear cell, plasma and serum analyses every two weeks during the initial 12-week observation period. Liver biopsy and treatment are offered if spontaneous clearance is not apparent within this period.

Histopathology studies on this cohort showed that fibrogenesis occurred early and was markedly accelerated in this group of subjects27: 17 of the first 20 biopsies, performed at a median of 4.3 months after the first noted increase in ALT levels, revealed stage 2 (of 4, Scheuer scale) fibrosis, a much greater number than reported in patients who acquired HCV infection before HIV infection.

Age and male gender may contribute to this rapid fibrosis progression, but no other known risk factors for fibrosis explain these findings. Treatment with pegylated interferon and weight-based ribavirin during the acute phase resulted in a 70 percent sustained viral response rate. Early spontaneous clearance occurred in approximately 15 percent of patients, but was not related to the occurrence of symptomatic hepatitis. Ongoing work centers on understanding factors contributing to the accelerated fibrosis progression, maximizing treatment response and characterizing factors contributing to this outbreak of acute HCV infection among HIV-infected men who have sex with men in New York City. Investigators of the Philadelphia Cohort collaborates in this study to characterize early immunologic responses in HIV-infected patients.

The work with this cohort has been funded by NIH DA016156 and DK066939.

ANDREA L. COX
KIMBERLY PAGE
JULIE BRUNEAU

NAGLAA H. SHOUKRY
GEORG M. LAUER
ARTHUR Y. KIM
HUGO R. ROSEN
HANK RADZIEWICZ
ARASH GRAKOUI
DANIEL S. FIERER
ANDREA D. BRANCH
DAVID E. KAPLAN
KYONG-MI CHANG*
*Associate Editor

References

Villano SA, Vlahov D, Nelson KE, et al.
Persistence of viremia and the importance of long-term follow-up after acute hepatitis C infection. Hepatology 1999; 29:908–914.

Cox AL, Mosbruger T, Lauer GM, et al.
Comprehensive analyses of CD8+ T cell responses during longitudinal study of acute human hepatitis C. Hepatology 2005;42:104–112.

Netski DM, Mosbruger T, Depla E, et al.
Humoral immune response in acute hepatitis C virus infection. Clin Infect Dis 2005;41:667–675.

Cox AL, Mosbruger T, Mao Q, et al. Cellular immune selection with hepatitis C virus persistence in humans. J Exp Med 2005;201:1741–1752.

Wolfl M, Rutebemberwa A, Mosbruger T, et al.
Hepatitis C virus immune escape via exploitation of a hole in the T cell repertoire. J Immunol 2008;181:6435– 6446.

Rutebemberwa A, Ray SC, Astemborski J, et al.
High programmed death-1 levels on HCV specific T cells during acute infection are associated with viral persistence and require preservation of cognate antigen during chronic infection. J Immunol 2008;181:8215–8225.

Hahn JA, Page-Shafer K, Lum PJ, et al.
Hepatitis C virus seroconversion among young injection drug users: relationships and risks. J Infect Dis 2002;186:1558– 1564.

Badr G, Bedard N, Abdel-Hakeem MS, et al.
Early interferon therapy for hepatitis C virus infection rescues polyfunctional, long-lived CD8_ memory T cells. J Virol 2008;82:10017–10031.

Moirand R, Bilodeau M, Brissette S, et al.
Determinants of antiviral treatment initiation in a hepatitis C-infected population benefiting from universal health care coverage. Can J Gastroenterol 2007;21:355–361.

Lechner F, Wong DK, Dunbar PR, et al.
Analysis of successful immune responses in persons infected with hepatitis C virus. J Exp Med 2000;191:1499–1512.

Timm J, Lauer GM, Kavanagh DG, et al.
CD8 epitope escape and reversion in acute HCV infection. J Exp Med 2004; 200:1593–1604.

Kuntzen T, Timm J, Berical A, et al.
Viral sequence evolution in acute hepatitis C virus infection. J Virol 2007;81:11658–11668.

Day CL, Seth NP, Lucas M, et al.
Ex vivo analysis of human memory CD4 T cells specific for hepatitis C virus using MHC
class II tetramers. J Clin Invest 2003; 112:831–842.

Lauer GM, Lucas M, Timm J, et al.
Fullbreadth analysis of CD8_ T-cell responses in acute hepatitis C virus infection and early therapy. J Virol 2005;79: 12979–12988.

Kasprowicz V, Ward SM, Turner A, et al.
Defining the directionality and quality of influenza virus-specific CD8_ T cell cross-reactivity in individuals infected with hepatitis C virus. J Clin Invest 2008; 118:1143–1153.

Northfield JW, Kasprowicz V, Lucas M, et al.
CD161 expression on hepatitis C virus-specific CD8_ T cells suggests a distinct pathway of T cell differentiation. Hepatology 2008;47:396–406.

Wang CC, Krantz E, Klarquist J, et al.
Acute hepatitis C in a contemporary U.S. cohort: modes of acquisition and factors influencing viral clearance. J Infect Dis 2007;196:1474–1482.

Tester I, Smyk-Pearson S, Wang P, et al.
Immune evasion versus recovery after acute hepatitis C virus infection from a shared source. J Exp Med 2005;201: 1725–1731.

Smyk-Pearson S, Tester IA, Klarquist J, et al.
Spontaneous recovery in acute human hepatitis C virus infection: functional T-cell thresholds and relative importance of CD4 help. J Virol 2008;82: 1827–1837.

Smyk-Pearson S, Golden-Mason L, Klarquist J, et al.
Functional suppression by FoxP3_CD4_CD25(high) regulatory T cells during acute hepatitis C virus infection. J Infect Dis 2008;197:46–57.

Golden-Mason L, Burton JR, Jr., Castelblanco N, et al.
Loss of IL-7 receptor alphachain (CD127) expression in acute HCV infection associated with viral persistence. Hepatology 2006;44:1098–1109.

Golden-Mason L, Palmer B, Klarquist J, et al.
Upregulation of PD-1 expression on circulating and intrahepatic hepatitis C virus-specific CD8_ T cells associated with reversible immune dysfunction. J Virol 2007;81:9249–9258.

Radziewicz H, Ibegbu CC, Hon H, et al.
Impaired HCV specific effector CD8+ T cells undergo massive apoptosis in the peripheral blood during acute HCV infection and in the liver during the chronic phase of infection. J Virol 2008.

Kaplan DE, Sugimoto K, Newton K, et al.
Discordant role of CD4 T-cell response relative to neutralizing antibody and CD8 T-cell responses in acute hepatitis C. Gastroenterology 2007;132:654–666.

Kaplan DE, Ikeda F, Li Y, et al.
Peripheral virus-specific T-cell interleukin-10 responses develop early in acute hepatitis
C infection and become dominant in chronic hepatitis. J Hepatol 2008; 48:903–913.

Nakamoto N, Kaplan DE, Coleclough J,et al.
Functional restoration of HC-specific CD8 T cells by PD-1 blockade is defined by PD-1 expression and compartmentalization. Gastroenterology 2008;134:1927–1937.

Fierer DS, Uriel AJ, Carriero DC, et al.
Liver fibrosis during an outbreak of acute hepatitis C virus infection in HIV-infected
men: a prospective cohort study. J Infect Dis 2008;198:683–686.

The authors gratefully acknowledge our patients and collaborators who have participated in our study.

The work with this cohort has been funded by NIH DA016156 and DK066939.
The authors disclose no conflicts. doi:10.1053/j.gastro.2008.11.049

Focus on Hepatitis C

Your online source for Hepatitis C and Opioid Treatment Programs