Point‐of‐care screening for sickle cell disease in low‐resource settings: A multi‐center evaluation of HemoTypeSC, a novel rapid test

Abstract

Sickle cell disease is a common, life-threatening genetic disorder that is best managed when diagnosed early by newborn screening. However, sickle cell disease is most prevalent in low-resource regions of the world where newborn screening is rare and diagnosis at the point-of-care is challenging. In many such regions, the majority of affected children die, undiagnosed, before the age of five years. A rapid and affordable point-of-care test for sickle cell disease is needed. The diagnostic accuracy of HemoTypeSC, a point-of-care immunoassay, for sickle cell disease was evaluated in individuals who had sickle cell disease, hemoglobin C disease, the related carrier (trait) states, or a normal hemoglobin phenotype. Children and adults participated in low-, medium- and high-resource environments [Ghana (n=383), Martinique (n=46), and USA (n=158)]. Paired blood specimens were obtained for HemoTypeSC and a reference diagnostic assay. HemoTypeSC testing was performed at the site of blood collection, and the reference test was performed in a laboratory at each site. In 587 participants, across all study sites, HemoTypeSC had an overall sensitivity of 99.5% and specificity of 99.9% across all hemoglobin phenotypes. The test had 100% sensitivity and specificity for sickle cell anemia. Sensitivity and specificity for detection of normal and trait states were >99%. HemoTypeSC is an inexpensive (<$2 per test), accurate, and rapid point-of-care test that can be used in resource-limited regions with a high prevalence of sickle cell disease to provide timely diagnosis and support newborn screening programs.

HemoTypeSC Demonstrates >99% Field Accuracy in a Sickle Cell Disease Screening Initiative in Children of Southeastern Uganda

“…6 HemoTypeSC is also inexpensive (< $2.00 per test) and highly accurate in newborns and young children with high fetal hemoglobin (HbF) level. 5 In this study we implemented HemoTypeSC as a standard of SCD diagnosis while simultaneously validating the test's accuracy in children of southeastern Uganda, with the study aimed at providing evidence for the applicability of the test in widespread newborn screening programs in the region.…”

Newborn Screening for Sickle Cell Disease in the Caribbean: An Update of the Present Situation and of the Disease Prevalence

“…Two of them, relying on lateral flow immunoassays, the SickleSCAN [21] and the HemoTypeSC tests [22], could be viable screening tools for the early diagnosis of SCD conducted by health workers with little expertise. Preliminary data using the HemoTypeSC test on a small series of children and adults in Martinique, in comparison with a larger series in Ghana and the USA, showed the good specificity and sensitivity of the test [23]. We plan to conduct larger studies to evaluate the performance and implementation feasibility of these POC testing devices as screening tools in Caribbean territories where the reference "gold-standard" tests, IEF, and HPLC are not available.…”

Systematic Screening of Neonatal Sickle Cell Disease with HemoTypeSC&lt;sup&gt;TM&lt;/sup&gt; Kit-Test: Case Study and Literature Review

“…Although data on child mortality are not widely available today, several authors report that 50% to 90% of sickle cell children die before the age of 5, undiagnosed [5] [9] [10]. There is a consensus that early diagnosis of SCD in neonates is necessary for initial management [4] [5] [8] [11]. In many resource-rich areas, universal neonatal screening programs associated with prophylactic interventions have significantly reduced SCD morbidity and mortality in the first 20 years of patients' life [4] [5] [12] [13] [14].…”

“…In many resource-rich areas, universal neonatal screening programs associated with prophylactic interventions have significantly reduced SCD morbidity and mortality in the first 20 years of patients' life [4] [5] [12] [13] [14]. However, in sub-Saharan Africa and central India, where more than 90% of sickle-cell births occur, neonatal screening programs are not systematically applied, if at all, mainly because of the cost and logistical burden of laboratory diagnostic tests [11] [13].…”

“…Rapid tests exploit either solubility properties of HbS and the cell density, or immunological approaches [15] [16]. All POC rapid tests have the advantage of saving time in terms of results and facilitating application in rural areas without electricity or qualified personnel [9] [11]. Several studies report that robust tests are available in high-income countries where they are considered worldwide as a "gold standard" for the diagnosis of sickle cell disease [18].…”