Evaluation of Saliva as an Alternative Specimen to Serum for Diagnosis of Hepatitis C Virus Infection

Aim: The study aimed at evaluation of saliva as an alternative specimen to serum for the detection of HCV Abs and HCV RNA.

Study Design: Comparative Study.

Place and Duration of Study: Department of Medical Microbiology and Immunology, and Department of Infectious Diseases and Endemic Hepatic and Gastrointestinal diseases, faculty of medicine, Cairo University, Cairo, Egypt. Between March 2013 and July 2013.

Methodology: The study was conducted on serum and saliva samples collected from 50 HCV-infected patients and 20 healthy controls. All serum and saliva samples were subjected to 3rd generation enzyme linked immune-sorbent assay (ELISA) for detection of HCV antibodies as well as real time RT-PCR assay for detection of HCV RNA. ELISA procedure for saliva samples was done according to a modified protocol, while 3 methods were used to calculate cut-off value (COV) above which saliva samples were considered positive.

Results: HCV antibodies were detected in all serum samples from patients but not in controls. Salivary HCV antibodies results for patients and controls differed according to the three methods used for determining the COV, with sensitivity ranged from 88 to 96% and specificity from 95 to 100%. No correlation existed between positivity of anti-HCV salivary Abs with either serum or salivary viral loads. Salivary real time RT-PCR had sensitivity and specificity of 100% for diagnosis of HCV infection with excellent significant correlation between the HCV viral loads in the saliva and serum.

Conclusions: Saliva can be used as an important substitute to serum for diagnosis of HCV infection either by detection of anti-HCV Abs or HCV RNA.