Journal of Clinical Virology - Volume 82 - Supplement 1 - September 2016

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Abstracts / Journal of Clinical Virology 82S (2016) S1–S142 S83
perspectives to investigate viral determinants responsible for the
different natural course and treatment outcome of hepatitis C as
well as to develop a vaccine. In this study we hypothesized that
this hindrance could be due to the presence of inhibitory factors in
patient serum.
Combining polyethylene glycol precipitation, iodixanol gradi-
ent and size exclusion chromatography, we obtained a purified
fraction enriched in inhibitory factors from a pool of HCV seroneg-
ative serums. Mass spectrometry analysis of this fraction identified
apolipoprotein(a) (apo(a)) as a potential inhibitor of the early step
of HCV life cycle. Apo(a) consists of ten kringle IV-like domains
(KIV), one kringle V-like domain (KV) and a protease-like domain
that are homologous to plasminogen domains. Each of the ten KIV
domains is present in a single copy with the exception of KIV type
2 (KIV 2), which is encoded in a variable number of tandemly
repeated copies by the apo(a) gene, which gives rise to several
apo(a) size isoforms in the human population. In addition, in human
serum, apo(a) covalently links to the Apolipoprotein B component
of a low density lipoprotein via a disulfide bridge to form a lipopro-
tein(a).
The inhibitory effect of apo(a) onHCV entrywas confirmed using
a recombinant virus derived from the JFH1 strain and supernatant
of cells transfected with plasmids expressing apo(a) as well as puri-
fied recombinant isoforms of apo(a). Our results also suggest that
the larger the protein is, the better the inhibition is. We are cur-
rently testing several deletion mutants of apo(a) to identify critical
domains for the inhibitory activity and to decipher the mechanism
of inhibition.
Altogether, our results identify apo(a) as an additional compo-
nent of the lipid metabolism modulating HCV infection.
Abstract no: 5
Presentation at ESCV 2016: Poster 125
Method comparison of VIDAS® ANTI-HBS TOTAL
II with three equivalent assays in the 5–40 IU/L
range critical for HBV vaccine status
establishment
G. Bouchard ∗ . Mossuz evet
Y. Ataman-Önal , L. Demonchaux , A. Dugua ,
S. Jares Ferrier , H. Convert , J.M. Dugua
1 bioMérieux, Marcy l ´étoile, France
2 CEA, Grenoble, France
Vaccine-induced protection from hepatitis B virus (HBV) infec-
tion is correlated with the presence of antibodies against HBs
antigen and individuals with a response ≥10 IU/L are considered
protected. Each anti-HBs assay detects parts of the polyclonal anti-
HBs response, depending on its capture phase design. Criteria
important for assay performance are equivalent recognition of HBV
subtypes ad/ay and metrological agreement at 10UI/L cut-off. This
later is not easy to achieve and discrepancies between assays were
repeatedly reported. Around 10UI/L, discrepant results can trans-
late into opposite clinical decisions regarding revaccination. We
have compared 4 anti-HBsT assays in order to determine the one
with the fewest discrepancies in the 0–40 IU/L range relevant for
revaccination decision.
99 samples of routine HBV vaccine follow-up were collected
from3 laboratories inGrenoble area (CEA, CHU andOriadeNoviale).
The recruitment criterion was a first anti-HBs result between 0 and
40 IU/L from one of the VIDAS, Architect or Cobas assays. In addi-
tion to these, all samples were also tested with the Biorad assay to
generate 4 anti-HBsT results for each sample. For result interpreta-
tion, <10 IU/L was considered negative and ≥10 IU/L was positive.
Inter-assay qualitative agreements were defined as follows: total
agreement is 4/4 positive or negative results, partial agreement is
one discrepant result out of 4 and no agreement is 2 vs 2.
54/99 of anti-HBsT results were in total agreement and 35/99
were characterized by only one discrepant assay out of 4. The dis-
crepancies were the following: 4 for VIDAS with 2 relative false
positives and 2 relative false negatives, 7 for Architect with 2 rela-
tive false positives and 5 relative false negatives, 11 for Biorad, all
relative false negatives, 13 for Cobas with 9 relative false positives
and 2 relative false negatives. 10/99 of results were indeterminate
and showed no agreement (2 vs 2).
Among 4 assays, VIDAS anti-HBs Total II had the fewest dis-
crepancies around the 10 IU/L cut-off owing to excellent analytical
characteristics and enabled the most reliable decisions for HBV
revaccination.
Abstract no: 59
Presentation at ESCV 2016: Poster 126
Study of HCV seroprevalence in adult
population in the Czech Republic
R. Chlibek , V. Stepanova ∗, L. Pliskova ,
J. Smetana lisek
1 Department of Epidemiology, Faculty of Military
Health Sciences, University of Defence, Hradec
Kralove, Czech Republic
2 Inst. of Clin. Microbiology, University Hospital and
Faculty of Medicine of Charles University, Hradec
Kralove, Czech Republic
3 Inst. of Clin. Biochemistry and Diagnostics,
University Hospital and Faculty of Medicine of
Charles University, Hradec Kralove, Czech Republic
4 Clinic of Infectious Diseases, University Hospital
and Faculty of Medicine of Charles University,
Hradec Kralove, Czech Republic
Background: Last official HCV seroprevalence survey in the
Czech Republic (CZ) was performed by National Institute of Public
Health (NIPH) in 2001 with HCV prevalence determined only 0.2%.
Nevertheless chronic hepatitis C (VHC) is one of the frequent indica-
tion for liver transplantation in CZ (15.6%). According to the official
report of NIPH up to 1000 of VHC cases and 82% VHC of all chronic
hepatitis are reported annually in CZ (2015). The aim of our work
was to determine the seroprevalence of HCV in CZ adult popula-
tion, HCV viraemia and HCV genotype in HCV RNA positive persons
and analyze the results as to the risk factors (i.v. drug users, health
care workers) and estimate the number of persons with chronic
hepatitis C in CZ.
Materials and methods: The examined group included 3000
adult persons visiting in 02–09/2015 research centres of Hradec
Kralove, Brno, Ceske Budejovice, males in48.83%, females in51.17%,
age 18–90, median age 46 years. Anti-HCV antibodies were exam-
ined by 3rd generation test, CMIA (enzymatic immunoassay with
chemiluminiscent detection), on Architect i2000, Abbott, with
cut off S/CO <1 = negative (nonreactive); 1–2 = borderline reactive;
>2 = positive (reactive). Samples with borderline reactivity were
confirmed with immunoblot RIBA in NIPH. To determine viraemia
all anti-HCV reactive samples were examined by RT–PCR, in HCV
RNA positive samples genotypes were determined.
Results: Of 3000 samples 50 were determined anti-HCV pos-
itive, seroprevalence of 1.67% (2.39% in males, 0.98% in females).
12 borderline reactive samples were confirmed negative by RIBA.