Hepatobiliary Neoplasia: Clinical and Experimental
101. Serum glypican 3 after curative hepatectomy predicts
early-phase recurrence of hepatocellular carcinoma.
K. Watanabe; T. Asano; Y. Hippo; A. Watanabe; Y. Midorikawa; S. Ohnishi; T. Kodama; M. Omata; M. Makuuchi; H. Aburatani
Background:
Hepatocellular carcinoma (HCC) is an end-result of chronic
infection with hepatitis B or C virus. High incidence of intrahepatic
recurrence remains a major problem in the treatment of HCC. We have reported
that serum glypican 3 is a potent biomarker especially for detection of
well-to-moderately differentiated HCC. In the clinical course of HCC, curative
treatment against tumor, preserved liver function and functional status of the
patients are the important prognostic factor for patients with HCC. Meanwhile,
the prognostic significance of glypican 3 has not been investigated in patients
with HCC. Therefore, the aim of this study is to evaluate usefulness of
glypican 3 as a biomarker of recurrent HCC after curative surgery.
Patients and Methods:
This study includes a total of 125 patients with HCC (64%
HCV) consecutively diagnosed and treated with curative hepatectomy at
University of Tokyo Hospital from October 2002 to December 2004. Curative
hepatectomy was confirmed by negative surgical margin and absence of
macroscopic vascular invasion. Serum glypican 3 was measured by sandwich ELISA.
Patient characteristics, tumor stage, pathological grade, anatomic resection
and serum tumor markers (alpha fetoprotein and glypican 3) were screened for
their prognostic significance by univariate and multivariate analysis.
Results:
In 125 patients, 43 cases experienced recurrence in the
follow up period (median; 15.5 months). Recurrence-free survival rate at 6
months and 1 year after surgery was 83.5% and 71.1%, respectively. In
multivariate analysis, pathological diagnosis of microsatellite nodule (hazard
ratio: HR 3.10, 95% confidence interval: CI 1.32-7.30, p < 0.01),
microvascular infiltration (HR 2.29, 95%CI 1.15-4.53, p=0.01), prolongation of
prothrombin time (HR 2.35, 95%CI 1.06-5.17, p=0.03) and serum glypican 3
measured postoperatively (glypican 3 > 0.3ng/ml: HR 2.46, 95%CI 1.04-5.82,
p=0.03) were significant factors associated with recurrence. Patients with
postoperative serum glypican 3 < 0.3 ng/ml of value was significantly higher
recurrence-free rate than patients with glypican 3 ≧ 0.3
ng/ml (91.9% vs 63.7% at 6 months and 80.2% vs 49.2% at one year, p < 0.001
by logrank test).
In conclusion, serum glypican 3 is useful as predictive
marker of recurrence after curative surgical treatment of HCC.
Clinical Biliary Tract Disorders
S1222. Incidence and Risk Factors for
Hepatic and Extrahepatic Malignancies in Primary Biliary Cirrhosis in
K. Sato; K. Hosonuma; M. Yanagisawa; T. Itikawa; N. Sohara; S. Kakizaki; H. Takagi; M. Mori
Background:
Hepatocellular carcinoma (HCC) have
been increasingly reported as a complication of primary bliliary cirrhosis
(PBC). However, no large case studies have focused on the detailed analysis of
the incidence ratio and risk factors for hepatic and extrahepatic malignancies
in PBC in
Methods:
Our aim was to analyze the incidence of malignancies in a
large series of PBC patients in
Results:
The overall sample included 239 patients (29 males, 210
females). The mean age was 57 years (range 24-86); Liver biopsy was performed
in 168 patients. One hundred and eight patients had Scheuer's stage 1, 33 had
stage 2, 16 had stage 3, and 11 had stage 4. The follow-up period was average
89 months per person. Extrahepatic malignancies developed in 14 cases (5.9%), and HCC in eleven cases (5.2%) which were not always
associated with cirrhosis. One case of HCC had positive HCV-RNA test but the
non-cancerous liver tissue was consistent with PBC. The SIR for HCC was 6.0
(95%CI 3.0-10.7), whereas the SIR for top four extrahepatic malignancies, the
colon, gastric, lung and breast cancer were 0.7 (95%CI 0.1-2), 0.6 (95%CI
0.1-1.7), 0.7 (95%CI 0.1-2.4), 1.2 (95%CI 0.1-4.3), respectively. Symptomatic
PBC showing icterus, ascites, varices, or hepatic coma was an independent risk
factor for HCC in overall PBC patients. When multivariate analysis was
restricted to female patients, Age, HCV-RNA, symptomatic PBC or family history
of HCC were independent risk factors for HCC. Diabetes mellitus,
hyperlipidemia, symptomatic PBC, or preexistence of HCC were
independent risk factors for extrahepatic malignancies in not only overall but
also female patients.
Conclusions:
The incidence of HCC but not extrahepatic malignancies was
significantly higher in PBC than those in the general population in
Clinical Hepatitis
S1225. Serum hepatocyte growth factor activator inhibitor type
1 is positively associated with hepatic fibrosis in patients with chronic
hepatitis C virus infection.
A. Moriuchi; H. Uto; S. Hasegawa; M. Oketani; Y. Takami; K. Kusumoto; K. Hayashi; A. Ido; T. Yamagishi; S. O. Stuver; H. Tsubouchi
Purpose:
Liver cirrhosis/fibrosis is characterized by excess
production and deposition of extracellular matrix components, leading to tissue
scarring and destruction of normal hepatic parenchyma. Hepatocyte growth factor
(HGF) activator inhibitor type 1 (HAI-1) is a serine protease inhibitor that
proteolytically cleaves and activates HGF. The mature membrane-form of HAI-1
can be proteolytically cleaved and released into the extracellular environment.
Although several studies have investigated the anti-fibrotic effect of HGF, how
the HGF/HAI-1 system is involved in hepatocyte repair and hepatic fibrosis has
not been fully clarified. The aim of this study is to elucidate the clinical
significance of serum HAI-1 in patients with chronic hepatitis C virus (HCV)
infection.
Methods:
A total of 454 subjects with chronic HCV infection were
included in this study. Chronic HCV infection was confirmed by the presence of
HCV antibodies and HCV RNA. An additional 89 chronic hepatitis C (CHC) patients
who underwent liver biopsy were also analyzed. Serum HAI-1 levels (ng/ml) were
assessed by enzyme-linked immunosorbent assay (ELISA). In addition to HAI-1,
serum levels of total HGF, activated HGF, platelet count, AST, HCV core protein
and hepatic fibrosis marker, type IV collagen 7S (IVcol7s) and hyarulonic acid
(HA) were also evaluated.
Results:
Mean HAI-1 serum levels were 7.5±2.3 in the healthy donors
(n=52). In the 454 HCV-infected subjects, serum HAI-1 levels were positively
correlated with IVcol7s (r=0.73, p<0.001) and HA (r=0.42, p<0.001).
However, there was no correlation between HAI-1 levels and total HGF, activated
HGF, AST, or HCV core protein levels. In the 89 patients with CHC, serum HAI-1
levels significantly increased with the severity of liver fibrosis [F1:12.5±7.6
(n=38); F2:18.2±9.6 (n=28); F3:26.4±11.0 (n=11); F4:30.1±13.0 (n=12)]
(p<0.001). In addition, the nine patients who remained responsive to
interferon therapy had significantly decreased mean HAI-1 levels (-7.6±2.0)
over the seven-year follow-up period, whereas in the 11 untreated patients,
mean HAI-1 levels increased during this observation period (18.0±3.9)
(p<0.001).
Conclusions:
HAI-1 is associated with hepatic fibrosis but not with HGF
levels. Serum HAI-1 levels may serve as a non-invasive, clinical marker for
hepatic fibrosis in HCV-infected patients. HAI-1 levels could also serve as a
surrogate marker for the antifibrotic effects of HCV treatment.
Esophagus
S1340. Clinical Predictors for Recurrence
of Esophageal Varices after Obliteration by Endoscopic Band Ligation.
V. Chandrasekhara; J.
Yepuri; J. Sreenarasimhaiah
Background:
There is no universal standard of care for endoscopic
follow-up after obliteration of esophageal varices by esophageal variceal
ligation (EVL).
Aim:
Identify clinical predictive factors and rate of varices
recurrence following EVL.
Methods:
All patients presenting to
Results:
Of 31 patients enrolled to date, 35% were Caucasian and 65%
were Hispanic. 71% of patients were male and 29% female with mean age of 48
years. At the initial time of EVL, 39% were still consuming alcohol. The cause
of cirrhosis was alcohol alone (26%), hepatitis C (HCV) alone (26%), combined
HCV and alcohol (23%), cryptogenic (9%), nonalcoholic fatty liver (3.2%),
primary biliary cirrhosis (3.2%), combined hepatitis B (HBV)/HCV (3.2%), and
combined alcohol/HBV/HCV (3.2%). Noncompliance with the EVL protocol was noted
in 10/31 (32%) patients. Of these, 4/10 (40%)were
Caucasian, 6/10 (60%) were Hispanic, 3/10 (30%) were non-English speaking, and
8/10 (80%)were actively consuming alcohol. Variceal rebleeding was noted in
8/31 (26%) within 1 year of initial EVL. Of these, 4/8 (50%) were non-compliant
with the EVL protocol. Alcoholic cirrhosis was noted in 5 of 8 (62.5%)
patients. Moreover, 4/5 (80%) were still actively drinking. For all 31
patients, the mean MELD score was 13.3 and the mean CPT score was 8.1. The mean
MELD score was 16.1 for those with variceal rebleeding and 12.3 for those
without rebleeding (p=0.013). The mean INR in the rebleeding group was 1.64 and
in the non-rebleeding group was 1.37 (p=0.017). The average age for the two
groups was 49.2 and 47.5 years, respectively. There has been one death thus far
due to a bleeding gastric lesion.
Conclusions:
Recurrence of variceal bleeding after EVL obliteration
occurred in those patients with a higher MELD score and specifically a higher
INR level when compared to those who did not bleed. Patients with alcoholic
cirrhosis had a higher rate of rebleeding. There was no correlation with
patient age. Rebleeding was higher in those who were noncompliant with the EVL
protocol including patients who were non-English speaking as well as those with
active alcohol consumption. Therefore, efforts needed to be directed to
facilitating patient compliance with medical care and abstinence from alcohol.
Clinical Hepatitis: Advances in the basis for and markers of progressive disease
585. Elevated levels of circulating
mesenchymal stem cells in patients with chronic hepatitis B and C.
J. A. Abrams; V. Jacob; J. S.
Manavalan; T. C. Wang; S. Wang
Background:
Adult stem cells play a crucial role in the repair and maintenance
of tissues. There are three major populations of adult stem cells: mesenchymal
stem cells (MSC), endothelial progenitor cells (EPC), and hematopoietic stem
cells (HSC). Mesenchymal stem cells generate fibrous connective tissue, bone,
cartilage, and the reticular network that supports blood cell formation. The
pathways that lead to hepatic fibrosis in chronic hepatitis are not completely
understood, and the recruitment of MSCs and other progenitor cells may be
involved in this process. We conducted an exploratory analysis of circulating
progenitor cells in patients with chronic viral hepatitis.
Methods:
Peripheral blood mononuclear cells (PBMCs) were isolated from
7 patients with chronic hepatitis B or C without cirrhosis and from 7 healthy
controls. Data were collected regarding age, gender, and stage of fibrosis on
liver biopsy. Quantification of circulating progenitor cells was performed by
flow cytometry. PBMCs were labeled with fluorochrome conjugated monoclonal
antibodies against CD45, CD34, CD133, VEGFR2, CD117, and CD44, and incubated
and washed prior to 6-color analysis using a LSR II flow cytometer. EPCs were
defined as CD34+ CD133+ VEGFR2+, HSCs as CD45+ CD34+ CD117+, and MSCs as CD45-
CD44+. Counts were expressed as number of progenitor cells per 10,000
mononuclear cells.
Results:
Patients with chronic hepatitis B or C had a significantly
higher mean number of MSCs per 10,000 mononuclear cells than healthy controls
(68.7 vs. 38.9, p=0.04) (Table 1). There was no difference between patients
with chronic viral hepatitis and controls with respect to number of circulating
EPCs (2.8 vs. 2.9, p=0.91) or HSCs (6.7 vs. 5.5, p=0.50). There was no
significant correlation between number of circulating MSCs and age, gender, or
stage of fibrosis on liver biopsy.
Conclusions:
Mesenchymal stem cells are present in significantly higher
levels in serum from patients with chronic hepatitis B and C than from healthy
controls. It is possible that recruitment of MSCs plays an important role in
the development of hepatic fibrosis. Further studies should be aimed at
defining the role of MSCs in hepatic fibrosis and identifying the signaling
mechanisms that trigger their recruitment.
|
|
Hepatitis B or C |
Controls |
p-value |
|
MSC |
68.7 (28.9) |
38.9 (18.1) |
0.04 |
|
EPC |
2.8 (1.3) |
2.9 (2.4) |
0.91 |
|
HSC |
6.7 (3.5) |
5.5 (2.9) |
0.50 |
Clinical Portal Hypertension Poster Session
T1039. Impact of prophylactic
antibiotics in cirrhotic patients presenting with sepsis.
L. Lim; S. Lim; D. Sutedja; Y. Dan; Y. Lee; C. Wai
Aim:
Cirrhotic patients are prone to infection.
Prophylactic antibiotics after an episode of spontaneous bacterial peritonitis
(SBP) could potentially select out resistant organisms, such as extended
spectrum beta-lactamase (ESBL)-producing organisms. We aimed to investigate the
characteristics and outcomes of patients with cirrhosis who were admitted for
sepsis of any source in our institution, which is a tertiary university liver
transplant center.
Methods:
All patients with liver cirrhosis admitted to our
institution from March 2004 to August 2006 for sepsis, who had documented
organisms in any body fluid cultures, including blood, urine, ascites, sputum
or pleural fluid, were retrospectively studied.
Results:
47 patients with a total of 63 admissions (16 for
SBP, 15 for urinary tract infection) were studied: 26 (55%) were male, aged
65.3±1.6 years, whose major etiology of cirrhosis were cryptogenic cirrhosis
(32%), chronic hepatitis B (26%), and alcoholic liver disease (26%). 13 (28%)
had hepatocellular carcinoma. Of the 63 admissions, fever and abdominal pain
was the presenting complaint in 36 (57%) and 26 (41%) respectively, with mean
white cell count at 9.1±0.9 x10(9)/L, and mean C-reactive protein at
6.8±0.7mg/dL. Organisms isolated in cultures were, in decreasing order of
frequency: Escherichia coli (22%), Klebseilla pneumoniae (18%), ESBL-producing
Escherichia coli (13%), ESBL-producing Klebseilla
pneumoniae (8%). Patients on prophylactic ciprofloxacin for prior SBP were more
likely to harbor ciprofloxacin-resistant organisms (90% vs. 43%, p=0.007), and
ESBL-producing organisms (50% vs. 15%, p=0.012) than those without. 5 of 6
(83%) episodes due to pneumonia compared with 12 of 57 (21%) episodes with
infection other than pneumonia resulted in death (p=0.001). 16 of 37 (43%)
septic episodes involving Child’s C patients resulted in death, compared with 1
of 26 (4%) involving Child’s A or B patients (p=0.001). The mean Child’s score
(12.9±0.4 vs 9.4±0.4, p= 0.000) and MELD score (24.4±1.9 vs 17.3±0.9, p=0.000)
were higher in those who died than those who survived. Using multivariate
analysis, high Child-Pugh score (OR=0.579, p=0.021) and pneumonia (OR=12.6,
p=0.043) had significant correlations with mortality.
Conclusions:
Sepsis, in particular pneumonia, was an important
cause of mortality in cirrhotics, especially in those with high Child-Pugh
score. Cirrhotics who were on antibiotic prophylaxis were more likely to be
infected with ESBL-producing organisms, and should be started empirically on
second line antibiotics such as carbapenems upon diagnosis.
Steatohepatitis: Clinical
T1064.
Health Utility Assessment Using SF-6D and Health Utility
Index (HUI) in Patients with Chronic Viral Hepatitis and Non-alcoholic Fatty
Liver Disaese (NAFLD).
A. Dan; J. Kallman; R. Srivastava; Z.
Younoszai; A. Kim; Z. M. Younossi
Introduction:
Assessment of health-related quality of life
(HRQL) and health utilities have become important aspects of clinical research.
Patient-derived utility-adjustments are frequently used in economic analysis.
Although SF-36 is widely used as a generic HRQL instrument for patients with
liver disease, extensive data on the health utilities of patients with liver
disease are not available. Recently, SF-6D has been developed to obtain utility
scores from the SF-36 questionnaire.
Aim:
To assess health
utilities of patients with chronic liver disease using two utilities
assessments (SF-6D and HUI). Methods: Patients with chronic liver disease
were identified from our HRQL databases with available clinical data, SF-36,
and HUI scores. SF-6D scores were calculated from SF-36.
Results:
140 patients were included[(42%
female, age 49.4±11.2, 36% Hepatitis B, 29% Hepatitis C, 24% cholestatic liver
disease, and 11% NAFLD. Analyses indicate that Hepatitis B patients had the
best HRQL as measured by the SF-6D subscales (only mental health scores did not
vary by health condition), while patients with Hepatitis C and cholestatic
liver disease had similar HRQL, and those with NAFLD/other had the poorest HRQL
(Table 1). HUI scores did not differ as much as SF-6D scores, but those scales
that varied also indicated that those with other liver diseases had the poorest
quality of life. Female patients experienced poorer HRQL as measured by the
pain, social functioning and vitality SF-6D subscales and six of the HUI
subscales. Older age was also moderately associated with many of the HRQL
subscales.
Conclusion:
SF-36 with SF-6D scoring provides not only a
generic assessment of HRQL but also a utility score that can be used for
economic analysis.
|
|
Cholestatic Liver Disease |
Hepatitis C |
Hepatitis B |
NAFLD/Other |
Possible Range |
|
SF-6D |
|
|
|
|
|
|
Physical Functioning |
4.5 (1.2) |
4.4 (1.6) |
5.0 (1.2) |
3.4 (1.9) ** |
1-6 |
|
Role limitation |
1.6 (.5) |
1.5 (.5) |
1.3 (.4) |
1.8 (.4) *** |
1-2 |
|
Social Functioning |
3.8 (1.2) |
3.6 (1.3) |
4.4 (.9) |
3.4 (1.5) ** |
1-5 |
|
Bodily Pain |
3.9 (1.3) |
3.9 (1.2) |
5.0 (1.3) |
3.9 (1.2) *** |
1-6 |
|
Mental Health |
4.5 (1.0) |
4.3 (1.1) |
4.6 (.8) |
4.1 (1.1) |
1-5 |
|
Vitality |
3.4 (1.5) |
3.3 (1.5) |
4.3 (1.0) |
3.1 (1.3) *** |
1-5 |
|
HUI- Mark 2 |
|
|
|
|
|
|
Overall |
0.8 (.2) |
0.7 (.2) |
0.9 (.2) |
0.7 (.2) ** |
0-1 |
|
Cognition |
0.9 (.1) |
0.9 (.1) |
1.0 (.1) |
0.9 (.1) |
0-1 |
|
Emotion |
0.9 (.1) |
0.9 (.2) |
0.9 (.1) |
0.9 (.2) |
0-1 |
|
Mobility |
1.0 (.1) |
0.9 (.1) |
1.0 (.0) |
0.9 (.2) * |
0-1 |
|
Pain |
0.9 (.2) |
0.8 (.2) |
0.9 (.2) |
0.9 (.3) |
0-1 |
|
Self Care |
1.0 (.2) |
1.0 (.2) |
1.0 (.1) |
0.9 (.3) |
0-1 |
|
Sensation |
0.8 (.1) |
0.8 (.2) |
0.9 (.1) |
0.8 (.1) |
0-1 |
*p<.05 **p<.01
***p<.001 Note: Higher values on utility scale
scores as presented above reflect higher HRQL.
T1084. Elevated Serum Alanine Aminotransferase
(ALT) Activity Does Not Increase Cardiovascular Disease (CVD) Mortality in the
C. E. Ruhl; J. E. Everhart
Introduction:
A concern exists that
nonalcoholic fatty liver disease may increase the risk of CVD independently of
metabolic syndrome components. In a prospective, national, population-based
sample, we examined whether elevated ALT was associated with increased risk of
all-cause and CVD mortality.
Methods:
Data were analyzed from 14,950 adult participants
in the third U.S. National Health and Nutrition Examination Survey, 1988-94,
who were negative for markers of viral hepatitis B and C. Abnormal ALT activity
was defined as >40 U/L in men or >31 U/L in women. Participants were
followed through 2000 for all-cause and CVD mortality as identified by death
certificate underlying-cause diagnoses. Hazard rate ratios (HR) for mortality
outcomes were calculated using Cox proportional hazards analysis to adjust for
CVD risk factors. All analyses incorporated sample weights and the design
effects of the survey.
Results:
The prevalence of elevated ALT was 5.3%. During
the up to 12 years of follow-up, the cumulative mortality was 13.9% (2,189
deaths) from all causes and 4.2% (665 deaths) from CVD. Participants with an
elevated ALT had a non-statistically significant 40% higher risk of all-cause
mortality both in age-adjusted analysis (HR=1.4, 95% confidence interval
(CI)=0.90-2.1) and after adjusting for multiple factors (HR=1.4, 95%
CI=0.88-2.3). Interestingly, the risk of CVD mortality was not increased among
persons with an elevated ALT in either age-adjusted (HR=1.1, 95% CI=0.44-2.8)
or multivariate-adjusted analysis (HR=1.0, 95% CI=0.37-2.9).
Conclusion:
In the
Epidemiology
W1044. Digestive Diseases in the Native American Population
of the
B. Kizer; H. Lazarte; G. Haynatzki; R. Patel; A. Dajani; J. O'Brien
Background:
Little is known about the prevalence of digestive diseases
among the Native American population from the
Methods:
A retrospective study of 449 randomly selected Fred Leroy
charts. Each patient chart was reviewed for medical and social history, and the
documentation of the prevalence, clinical presentation, and treatments of the
ten most common digestive diseases in the
Results:
449 patient charts were reviewed. 138 patients were male; 311
were female. 330 patients were 19 to 50 years old; 119 patients were aged 50 to
79.
The Body Mass Index could be calculated for all but 2
patients. 113 patients were overweight (BMI 25 to < 30), 131 were obese (BMI
30 to < 35), and 137 were morbidly obese (BMI > 35). The prevalence in
this study population of overweight / obesity is 85.3 % (p<0.00001,
No statistical difference existed between the study
population and the
61 patients (13.6%) have a history of cholelithiasis. No
statistically significant difference exists between the prevalence of
cholelithiasis in this Native American population and the
27 patients (6%, p<0.00001) have a history of Hepatitis C
infection (
Conclusion:
This is the first study looking at the prevalence of
digestive diseases in the Native American population of the
Immune Response
280. The Envelope Protein of the Hepatitis C virus (E2)
inhibits IL-2 Secretion from T lymphocytes.
D. Petrovic; L. Golden-Mason; S. Mitchell; Y. Volkov; C. O'Farrelly; D. Kelleher; A. Long
Introduction:
T-cell activation is one of the primary responses of the
adaptive immune system to pathogens, such as Hepatitis C virus (HCV).
Recognition of antigen, via the T cell receptor, initiates signal transduction
and the resultant production of IL-2 is central to this response. We have
previously demonstrated that the PKC-B enzyme is critical for the process of
IL-2 secretion but not mRNA production (Long; et al). More recently we have shown
that the Envelope Protein (E2) of the HCV, through its interaction with CD81,
modulates PKC-B activity by stimulating its sequestration in lipid rafts,
preventing T cell migration (Volkov; et al).
Aim:
The aim of this study was to investigate the effect of HCV E2
on T cell IL-2 production.
Results:
Analysis of cytokine levels in extracts of snap-frozen liver
biopsies from individuals infected with HCV, measured by ELISA, revealed
significantly lower levels of IL-2 in these patients when compared to those
with other inflammatory liver diseases, such as ALD and PBC (IL-2 levels in
ng/100mg protein: 5 ± 0.93 (HCV) vs 25 ± 2.9 (ALD), p<0.027 vs 20 ± 2 (PBC),
p<0.003). In a HuT 78 T cell line model, pretreatment of cells with E2
substantially attenuated PMA stimulated IL-2 production (IL-2 levels in pg/ml:
PMA stimulated cells 889.3 ± 19.1 vs E2/PMA stimulation 105.9 ± 0.2,
p<0.016, (resting cells 20 ± 0.9)). This was also observed in PBMCs,
obtained from healthy donors, stimulated with either PMA/Ionomycin or anti CD3
/ anti CD28 antibodies (IL-2 levels in pg/ml: antiCD3/antiCD28 1825 ± 58.3 vs
E2/antiCD3/antiCD28 53 ± 1.5, p<0.022, (resting cells 27.4 ± 1.4)). In
contrast, cells pretreated with viral core protein C22 and NS3 protein C33 did
not affect IL-2 secretion, confirming specificity of E2 in inhibition of IL-2
secretion. Inhibition of IL-2 was at the level of secretion and not
transcription, as demonstrated by Real Time PCR (IL-2 mRNA level in PMA
stimulated cells increased 2.07 fold over resting cells, p<0.01 while it
increased IL-2 mRNA 2.19 fold in the presence of E2, p<0.0005). In addition,
intracellular IL-2 was detectable by immunofluorescence in PMA activated cells
pretreated with E2. Treatment of the HuT 78 cells with the lipid raft disruptor
methyl-β-cyclodextrin (MCD) reversed the ability of E2 to inhibit IL-2
secretion.
Introduction:
These data suggest that targeting of PKC-B to the lipid raft
microdomains in the T cell membrane, following E2 - CD81 interaction, disrupts
the association of PKC-B with the microtubule cytoskeleton, thereby inhibiting
export of IL-2. E2-mediated inhibition of IL-2 secretion represents a mechanism
whereby HCV can undermine the human immune response to establish persistent
infection and chronic disease.