R B Sawant1, Z S Bharucha, S B Rajadhyaksha. 1. Advanced Centre for Treatment Research and Education in Cancer (ACTREC), Department of Transfusion Medicine, Tata Memorial Centre, Sector 22 Kharghar, Navi Mumbai 410208, India. sawantrb72@rediffmail.com
Abstract
INTRODUCTION: The copper sulphate (CuSO4) specific gravity test for Hb screening tends to give inappropriate failures. This prompted us to compare it with alternate screening methods. AIM: To study the impact of inaccuracy of CuSO4 method on donor deferral. METHODS: Capillary and venous blood samples of 400 potential blood donors failing the primary Hb screening using appropriately standardized CuSO4 test (specific gravity 1.053) were tested by Hemocue photometer, the Hb colour scale, Cyanmethemoglobin method as well as the automated hematology analyser, which was considered as the standard reference method. RESULTS: One hundred and sixteen donors (29%) who failed the CuSO4 test had true Hb levels >12.5 g/dl. The Hb levels of 131 (32.8%) deferred donors were between 12 and 12.5 g/dl. The sensitivity of Hemocue, Hb colour scale and Cyanmethemoglobin was 99%, 97% and 96% and their specificity was 45%, 93% and 46%, respectively. The positive predictive values (PPV) of Hemocue and Cyanmethemoglobin methods were low (43% and 44%, respectively) but their negative predictive values (NPV) were high (99%, and 97%, respectively). The Hb colour scale had an overall best performance with a PPV of 96% and NPV of 95%. CONCLUSION: The Hemoglobin colour scale which is inexpensive, convenient for field testing and has the overall best performance, is the most suitable for donor Hb screening. Since its readability is 12 g/dl, lowering the donor Hb threshold to 12 g/dl should be actively considered.
INTRODUCTION: The copper sulphate (CuSO4) specific gravity test for Hb screening tends to give inappropriate failures. This prompted us to compare it with alternate screening methods. AIM: To study the impact of inaccuracy of CuSO4 method on donor deferral. METHODS: Capillary and venous blood samples of 400 potential blood donors failing the primary Hb screening using appropriately standardized CuSO4 test (specific gravity 1.053) were tested by Hemocue photometer, the Hb colour scale, Cyanmethemoglobin method as well as the automated hematology analyser, which was considered as the standard reference method. RESULTS: One hundred and sixteen donors (29%) who failed the CuSO4 test had true Hb levels >12.5 g/dl. The Hb levels of 131 (32.8%) deferred donors were between 12 and 12.5 g/dl. The sensitivity of Hemocue, Hb colour scale and Cyanmethemoglobin was 99%, 97% and 96% and their specificity was 45%, 93% and 46%, respectively. The positive predictive values (PPV) of Hemocue and Cyanmethemoglobin methods were low (43% and 44%, respectively) but their negative predictive values (NPV) were high (99%, and 97%, respectively). The Hb colour scale had an overall best performance with a PPV of 96% and NPV of 95%. CONCLUSION: The Hemoglobin colour scale which is inexpensive, convenient for field testing and has the overall best performance, is the most suitable for donor Hb screening. Since its readability is 12 g/dl, lowering the donor Hb threshold to 12 g/dl should be actively considered.
Authors: Massimo Daves; Roberto Cemin; Elmar M Zagler; Alexandra Joos; Stefan Platzgummer; Rudolf Hueber; Giuseppe Lippi Journal: Blood Transfus Date: 2016-01-19 Impact factor: 3.443
Authors: Adrian Bruhin; Lorenz Goette; Simon Haenni; Lingqing Jiang; Alexander Markovic; Adrian Roethlisberger; Regula Buchli; Beat M Frey Journal: Transfus Med Hemother Date: 2019-05-27 Impact factor: 3.747