High antibody level: an accurate serologic marker of viremia in asymptomatic people with hepatitis C infection

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http://www3.interscience.wiley.com/journal/123243110/abstract

Transfusion

Early View (Articles online in advance of print)

Published Online: 15 Jan 2010

© 2010 AABB

ORIGINAL RESEARCH

High antibody level: an accurate serologic marker of viremia in asymptomatic

people with hepatitis C infection

Ana M. Contreras, Rodolfo J. Ochoa-Jiménez, Alfredo Celis, Méndez,

Olivares, E. Rebolledo, Isabel -Lugo, Ana I.

Aguirre-Zavala, Jiménez-Méndez, and T. Chung

From the Health Research Council in Jalisco State, Mexican Institute of Social

Security; the Medical Research Unit, the Department of Internal Medicine, the

Molecular Diagnostic Laboratory, and the Central Blood Bank, Specialties

Hospital, West National Medical Center, Mexican Institute of Social Security;

and the Public Health Department, Health Sciences Center, Guadalajara

University, Guadalajara, Jalisco, Mexico; the Department of Internal Medicine,

General Hospital 1, Mexican Institute of Social Security, Colima, and the

Department of Internal Medicine and the Clinic of Sexually Transmitted Diseases,

Regional Hospital of Colima, Colima, Mexico; the External Section of

Pharmacology, CINVESTAV, National Politechnic Institute, Mexico City, Mexico;

and the Gastrointestinal Unit, Massachusetts General Hospital, Boston,

Massachusetts.

Correspondence to Ana M. Contreras, Health Research Council in Jalisco State,

Mexican Institute of Social Security, Pedro de Alarcón No. 45-61, Jardines

Vallarta, Zip Code 45120, Zapopan, Jalisco, México; e-mail:

acontreras53@....

Partial grant support was provided by cosHCVir study, SALUD-2005-01-14158, and

a scholarship (Dr Ochoa-Jiménez) by the National Council of Science and

Technology (CONACyT). An unrestricted educational grant was provided from Grupo

Roche Syntex de Mexico. The funding organizations had no role in the design and

conduct of the study; collection, management, analysis, and interpretation of

the data; or preparation, review, or approval of the manuscript.

Copyright © 2010 AABB

ABSTRACT

BACKGROUND: The screening and diagnosis of hepatitis C virus (HCV) infection is

initiated by testing for antibody to HCV (anti-HCV). A positive anti-HCV test in

blood donors represents ongoing infection in only a variable proportion of

individuals. Because a high anti-HCV level has been associated with viremia, a

study was conducted to determine whether a high antibody level is an accurate

serologic marker for viremia in asymptomatic anti-HCV–positive persons.

STUDY DESIGN AND METHODS: In a diagnostic test study, we included 856

anti-HCV–positive blood donors in a blood bank at Guadalajara, Jalisco,

Mexico, between 2002 and 2007. A third-generation amplified chemiluminescence

assay (ChLIA HCV) was used to detect anti-HCV. A positive result of the

qualitative nucleic acid test (HCV RNA) was considered the gold standard for

viremia.

RESULTS: By receiver operating characteristic analysis, the signal-to-cutoff

(S/CO) ratio of 20 or more was chosen as optimal to identify viremia and so was

defined as high anti-HCV level. There was a significant difference in the

proportion of viremia between subjects with high antibody level and those with

lower levels (93.7% vs. 1.8%, respectively; p < 0.001). A high antibody level

showed a sensitivity for viremia of 96.6% (95% confidence interval [CI],

93.8%-98.1%), a specificity of 96.6% (95% CI, 94.8%-97.8%), and a likelihood

ratio of 28.6 (95% CI, 18.4%-44.6%).

CONCLUSION: A high antibody level (S/CO ratio ≥20 by ChLIA HCV) clearly

divides the viremic from the nonviremic blood donors and functions as an

accurate serologic marker to guide the use of routine HCV RNA testing to confirm

hepatitis C infection.

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Received for publication July 29, 2009; revision received October 15, 2009, and

accepted November 17, 2009.

DIGITAL OBJECT IDENTIFIER (DOI)

10.1111/j.1537-2995.2009.02571