Utility of paper-based sickle cell test compared to sodium metabisulfite sickling test using hemoglobin electrophoresis as a gold standard at Bugando Medical Center, Mwanza

Abstract

BACKGROUND: Sickle cell disease (SCD) describes a group of inherited red blood cell disorders. People with SCD have abnormal haemoglobin (Hb), called Hb S. In all forms of SCD, at least one of the two abnormal genes causes a person's body to make Hb S. In countries with limited resources, diagnostic technique should be simple and easy to perform with high sensitivity and specificity. METHODS: This study compared the paperbased sickle cell test and sodium metabisulfite sickling test using Hb electrophoresis as a gold standard. It was a crosssectional hospitalbased study which was conducted from July to October 2017 involving a total of 140 blood samples of under 10 years children presumed to have SCD. Blood samples in ethylenediaminetetraacetic acid anticoagulantcontaining vacutainers were used for SCD diagnosis by using paperbased and sodium metabisulfite sickling tests then confirmed by Hb electrophoresis as the gold standard. RESULTS: Blood specimens were from individuals aged 4 years ranged from 2 to 9 years. Slightly majority of blood specimens belonged to males, 54.3% (76/140) while the majority was from inpatients, 82.9% (116/140). Paperbased sickle cell test identified 46/140 (32.9%) Hb AA, 81/140 (57.9%) Hb, and 6/140 (4.3%) Hb AS. Sickling test identified 50/140 (35.7%) Hb AA and 87/140 (62.1%) Hb SS. Hb electrophoresis identified 50/140 (35.7%) Hb AA, 83/140 (59.3%) Hb SS, and 7/140 (5%) Hb AS. The paperbased sickle cell test had a sensitivity of 97.8% and specificity of 96.7% while the sickling test had the sensitivity of 96.7% and specificity of 100%. CONCLUSION: Paperbased sickle cell test was able to detect sickle cell carriers, Hb AS and shown high sensitivity and specificity; therefore, it can be used as a substitute for sickling test in countries with limited resource. However, paperbased sickle test is suitable for adults' population.