Diagnostic accuracy of HemoTypeSC for detecting sickle cell disease in newborns: A multicentric study

Background & objectives Sickle cell disease (SCD) is a common, life-limiting genetic disorder in India. It is best managed when diagnosed early through newborn screening, which requires a reliable, rapid and an affordable point-of-care test for diagnosis. The study aimed to evaluate the diagnostic accuracy of HemoTypeSC as point-of care for detecting SCD in newborn screening. Additionally, the study assessed the feasibility of implementing HemoTypeSC in poor resource settings. Methods We conducted a prospective multicentre diagnostic accuracy study using an investigational assay HemoTypeSC, and compared it with the reference ('Gold-standard') High performance liquid chromatography (HPLC) during the year 2019-20. Six different study centers were selected to evaluate the performance of the test across different climatic and geographical locations. Results A total of 1725 newborn babies were screened from six participating centers. The samples were analyzed by both HemoTypeSC and HPLC. HemoTypeSC correctly identified the 14/15 SCD cases [sensitivity 93.3% (95% confidence interval (CI): 68-99.8%) and specificity 100% (95% CI: 99.7-100%)] and 192/200 sickle cell trait cases [sensitivity 96% (92.2-98.2%, CI 95%) and specificity 99.8% (95% CI: 99.5-99.9%)]. The accuracy of HemoTypeSC to detect SCD and sickle cell trait was found to be 99.9 per cent (95% CI: 99.6-100%) and 99.5 per cent (95% CI: 99-99.7%), respectively. Interpretation & conclusions HemoTypeSC can be a viable alternative to HPLC in resource-limited regions with a high prevalence of SCD to provide timely diagnosis and support newborn screening programmes.