Asian Journal of Transfusion Science

ORIGINAL ARTICLE
Year
: 2016  |  Volume : 10  |  Issue : 1  |  Page : 75--78

Role of signal-to-cut-off ratios of anti-hepatitis C virus antibody by enzyme immunoassays along with ID-NAT for screening of whole blood donors in India


Satyam Arora, Veena Doda 
 Department of Transfusion Medicine, Dr. Ram Manohar Lohia Hospital, New Delhi, India

Correspondence Address:
Satyam Arora
Department of Transfusion Medicine, Dr. Ram Manohar Lohia Hospital, New Delhi - 110 001
India

Background: The use of elevated signal-to-cut off ratios (S/CO) as an alternate to further supplemental testing (i.e., RIBA) has been included in the guidelines provided by the Centres for Disease Control and Prevention for HCV diagnostic purposes since 2003. With availability of screening by NAT and non availability of RIBA, further confirmation of HCV infection has been possible at the molecular level (RNA). Aims: To study the role of S/CO ratios of anti hepatitis C virus antibody detection by enzyme immunoassays (EIA) along with ID-NAT for screening of whole blood donors. Methods: In this study we reviewed the donor screening status for anti HCV from January 2013 to May 2014. All the donations were screened for anti HCV with fourth generation ELISA (BioRad Monolisa Ag-Ab Ultra) as well as with ID NAT (Procleix Ultrio). The S/CO ratio of all the anti-HCV reactive samples were analysed for their presence of HCV RNA. Results: On screening 21,115 donors for HCV, 83 donors (0.39%) were found reactive on pilot tube and repeat plasma bag testing (S/Co ratio ≥1) by ELISA. 41 donors were HCV RNA reactive with ID-NAT. 4 samples out of 41 were NAT yields and 37 were concordant reactive with ELISA. The S/Co ratio of anti-HCV reactive samples ranged from 0.9-11.1 [mean = 5.1; SD ΁ 2.9] whereas S/Co ratio of anti HCV and NAT reactive samples (concordant positives) ranged from 4.1-11.1 [mean 7.3]. In our analysis we found that S/CO ratio of 4 showed positive predictive value (PPV) and sensitivity of 100%. Summary/Conclusions: Our study showed that S/CO of 4 for anti HCV on ELISA would have maximum positive predictive value of having donor with HCV RNA. S/CO ratio of 4 is very close to 3.8 which was the CDC guideline. The presence of anti-HCV does not distinguish between current or past infections but a confirmed anti-HCV-positive result indicates the need for counseling and medical evaluation for HCV infection.


How to cite this article:
Arora S, Doda V. Role of signal-to-cut-off ratios of anti-hepatitis C virus antibody by enzyme immunoassays along with ID-NAT for screening of whole blood donors in India.Asian J Transfus Sci 2016;10:75-78


How to cite this URL:
Arora S, Doda V. Role of signal-to-cut-off ratios of anti-hepatitis C virus antibody by enzyme immunoassays along with ID-NAT for screening of whole blood donors in India. Asian J Transfus Sci [serial online] 2016 [cited 2021 Dec 1 ];10:75-78
Available from: https://www.ajts.org/article.asp?issn=0973-6247;year=2016;volume=10;issue=1;spage=75;epage=78;aulast=Arora;type=0