An evaluation of different saliva collection methods for detection of antibodies against hepatitis C virus (anti-HCV)

Authors


Livia Melo Villar, Viral Hepatitis Laboratory, Helio and Peggy Pereira Pavillion, Ground Floor, Room B09, Oswaldo Cruz Institute FIOCRUZ, Av. Brasil 4365 Manguinhos-RJ, Postal Code 21045900, Rio de Janeiro, RJ, Brazil. Tel: +55 21 21 25621918, Fax: +55 21 2270 6397, E-mail: lvillar@ioc.fiocruz.br

Abstract

J Oral Pathol Med (2012) 41: 793–800

Background:  Saliva samples can be used as an alternative fluid for against hepatitis C virus (anti-HCV) detection owing to the ease of collection and excellent acceptability. This study was conducted to optimize a commercial enzyme immunoassay (EIA) to detect anti-HCV in saliva samples.

Methods:  Ninety-six individuals donated paired serum and saliva samples that were obtained, using a commercial device (Salivette) and spitting into a sterile container. Initially, elution buffer for the Salivette samples, sample volume, incubation time and temperature, and two different anti-HCV EIAs were evaluated. Using the optimized assay, three methods for cut-off calculation were also evaluated.

Results:  A 20-fold increase in the sample volume for both collection methods was needed. Moreover, the Radim assay was the most appropriate assay for anti-HCV detection in saliva samples, and the quality parameters were increased when a ROC curve was used to determine the cut-off value. Using this optimized assay, the sensitivities, specificities, accuracies, positive and negative predictive values were above 90% for saliva obtained using both the Salivette and spitting methods. Using this assay, discordant false-negative results were obtained for only two Salivette samples and five spitting samples. The concordance kappa was 93% for the Salivette method and 86.1% for the spitting method, demonstrating excellent performance.

Conclusions:  Saliva samples obtained for both methods can be employed for anti-HCV detection among HCV-infected or HCV-suspected cases, but several modifications must be performed on commercial EIAs to obtain good results. Moreover, samples obtained with commercial devices are more appropriate for anti-HCV detection in saliva samples.

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