Asian Journal of Transfusion Science
Home About Journal Editorial Board Search Current Issue Ahead of print Back Issues Instructions Subscribe Login  Users: 322 Print this page  Email this page Small font sizeDefault font sizeIncrease font size 
Year : 2016  |  Volume : 10  |  Issue : 1  |  Page : 71-74

Impact of grey zone sample testing by enzyme-linked immunosorbent assay in enhancing blood safety: Experience at a tertiary care hospital in North India

1 Department of Transfusion Medicine, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Dubagga, Lucknow, Uttar Pradesh, India
2 Department of Transfusion Medicine, Charak Hospital and Research Centre, Dubagga, Lucknow, Uttar Pradesh, India

Correspondence Address:
Abhay Singh
Department of Transfusion Medicine, Charak Hospital and Research Centre, Dubagga, Hardoi Road, Lucknow, Uttar Pradesh
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0973-6247.164272

Rights and Permissions

Background: Enzyme-linked immunosorbent assay (ELISA) used for screening blood donors for transfusion transmitted infections (TTIs) can sometimes fail to detect blood donors who are recently infected or possessing the low strength of pathogen. Estimation of a grey zone in ELISA testing and repeat testing of grey zone samples can further help in reducing the risks of TTI in countries where nucleic acid amplification testing for TTIs is not feasible. Materials and Methods: Grey zone samples with optical density (OD) lying between cut-off OD and 10% below the cut-off OD (cut-off OD × 0.9) were identified during routine ELISA testing. On performing repeat ELISA testing on grey zone samples in duplicate, the samples showing both OD value below grey zone were marked nonreactive, and samples showing one or both OD value in the grey zone were marked indeterminate. The samples on repeat testing showing one or both OD above cut-off value were marked positive. Results: About 119 samples (77 for hepatitis B virus [HBV], 23 for human immunodeficiency virus [HIV], and 19 for hepatitis C virus [HCV]) were found to be in grey zone. On repeat testing of these samples in duplicate, 70 (58.8%) samples (45 for HBV, 12 for HIV, and 13 for HCV) were found to be reactive. Six (5%) samples (four for HBV, one for HIV, and one for HCV) were found to be indeterminate. Conclusion: Seventy donors initially screened negative, were found out to be potentially infectious on repeat grey zone testing. Thus, estimation of grey zone samples with repeat testing can further enhance the safety of blood transfusion.

Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)

 Article Access Statistics
    PDF Downloaded126    
    Comments [Add]    

Recommend this journal


Association Contact us | Sitemap | Advertise | What's New | Copyright and Disclaimer | Privacy Notice

2006 - Asian Journal of Transfusion Science | Published by Wolters Kluwer - Medknow
Online since 10th November, 2006