~ 103 ~ International Journal of Clinical and Diagnostic Pathology 2021; 4(3): 103-106 ISSN (P): 2617-7226 ISSN (E): 2617-7234 www.patholjournal.com 2021; 4(3): 103-106 Received: 18-05-2021 Accepted: 22-06-2021 Dr. Keyuri Patel Professor and Head, Department of Pathology, PramukhSwami Medical College, Karamsad, Gujarat, India Dr. Mustafa Ranapurwala Professor, Department of Pathology, PramukhSwami Medical College, Karamsad, Gujarat, India Dr. Anjali Patel 3rd year Resident, Pramukh Swami Medical College, Karamsad, Gujarat, India Dr. Neelofarbanu Mansuri Senior Resident, Pramukh Swami Medical College, Karamsad, Gujarat, India Corresponding Author: Dr. Mustafa Ranapurwala Professor, Department of Pathology, PramukhSwami Medical College, Karamsad, Gujarat, India Utility of grey zone sample testing strategy for transfusion transmittable infections to improve blood safety of a tertiary care center Dr. Keyuri Patel, Dr. Mustafa Ranapurwala, Dr. Anjali Patel and Dr. Neelofarbanu Mansuri DOI: https://doi.org/10.33545/pathol.2021.v4.i3b.396 Abstract Background: Grey zone samples with optical density (OD) lying between cut-off OD and 10% below the cut-off OD were identified during routine transfusion transmissible infectious disease screening by Enzyme-linked immunosorbent assay and its application in blood transfusion services. Materials and Methods: The present is an observational study where blood donors samples have been screened by performing repeat ELISA testing on Grey zone samples in duplicate at the A.D Gorwala Blood Centre, Karamsad between January 2018 to December 2020. Results: A total of 20560 blood donors were screened during the study period, out of which 12 blood donors were found to be in grey zone. On repeat testing of these, 02 were found to be reactive and 01 was found to be in grey zone again. Conclusion: Appropriate quality control measures can improvise the current screening methodologies in TTIs of blood bank centres, especially in resource constrained settings, where the NAT technology is not financially feasible. Keywords: grey zone, transfusion transmissible infectious, immunosorbent, ELISA, blood donors Introduction Blood transfusion is a life-saving measure in emergencies and is important for the medical / surgical management of most of the patients. Among all adverse effects of transfusion, transfusion transmitted infections (TTI) are very important. In India these include human immunodeficiency virus (HIV), Hepatitis B virus (HBV), Hepatitis C virus (HCV), Malaria parasite (MP) and Syphilis. As per Drugs and Cosmetics Act, 1940 and Rules, 1945, it is mandatory to test all blood donations for HIV, HBV, HCV, syphilis, and malaria in blood centers [1] . Integrated strategy for the provision of safe blood and blood products includes recruitment and retention of blood donors who are at low risk of transmitting infection, stringent donor screening consisting of meticulous donor history and examination, quality-assured screening of all donated blood units for transfusion transmissible infections (TTI), rational use of blood to reduce unnecessary transfusions, and the use of alternatives to transfusion, wherever possible [2] . The risk of transfusion transmitted infections is estimated to be 1 in 6,77,000 units for HIV, 1 in 1,03,000 for HCV, and 1 in 63,000 for HBV [3] . Blood transfusion is an effective mode of transmission of TTIs as it allows entry of large quantity of infective virions into the recipients. In multiply transfused hemophiliac patients, the prevalence of HCV was found to be as high as 23.9% [4] . In India, mandatory screening for HCV was implemented quiet late in 2002. Screening of blood donors for infectious markers such as human immunodeficiency virus (anti-HIV), hepatitis B virus (HBsAg), and hepatitis C virus (anti-HCV) is commonly done by immunoassay in the form of antigen/antibody detection methods, such as enzyme-linked immunosorbent assay (ELISA) or chemiluminescence immuno-assay (CLIA) [5] . Nucleic acid testing (NAT) is a newer molecular technique for screening blood donations to reduce the risk of transfusion transmitted infections (TTIs) in the recipients, based on amplification of targeted regions of viral ribonucleic acid or deoxyribonucleic acid (DNA), thus, narrowing the window period and providing an additional layer of blood safety. However, it is highly technically demanding, involving issues of high costs, dedicated infrastructure facility,