An evaluation of different saliva collection methods for detection of antibodies against hepatitis C virus (anti-HCV).
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.
Viral Hepatitis Laboratory, Oswaldo Cruz Institute FIOCRUZ, Rio de Janeiro, Brazil.
H M
HM
Cruz
V A
VA
Marques
C A
CA
Villela-Nogueira
K M R
KM
do Ó
L L
LL
Lewis-Ximenez
E
E
Lampe
L M
LM
Villar
D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D018937:Hepatitis C Antibodies / Q000032:analysis*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry / Q000276:immunology*; D012471:Salivary Proteins and Peptides / Q000276:immunology*; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D055815:Young Adult
D018937:Hepatitis C Antibodies; D012471:Salivary Proteins and Peptides