The test can be especially valuable for rapid detection and newborn screening programs in regions with low healthcare resources.
The study, “Point‐of‐Care Screening for Sickle‐Cell Disease in Low‐Resource Settings: a Multi‐Center Evaluation of HemoTypeSC, a Novel Rapid Test,” was published in the American Journal of Hematology.
Sickle cell disease (SCD) is highly prevalent in sub-Saharan Africa and central India. Sickle cell anemia is the most common and severe form of SCD.
In sub-Saharan Africa, where up to 90% of children with SCD are thought to die undiagnosed before the age of five, screening tests in newborns have not been implemented universally, the authors wrote. According to the World Health Organization, early diagnosis and prevention can avert 70% of the deaths that occur in these regions due to SCD.
However, the available diagnostic tests are costly and may take weeks or even months to inform the family of the diagnosis. So, an on-the-spot, diagnostic tool for SCD is an urgent need.
HemoType SC, developed by Silver Lake Research, is a diagnostic test to determine, using a very small about of blood, the type of hemoglobin — normal, sickle cell, or carrier — within 10 minutes. Using monoclonal antibodies, the test can distinguish between hemoglobin (Hb) deficiency subtypes including sickle cell disease (HbSS), hemoglobin C disease (HbCC), and respective carrier states (HbS and HbC).
It is an inexpensive alternative costing less than $2 (€ 1.74 ) per test. Moreover, it requires no instrumentation, electricity, or refrigeration.
In this global, multi-center study (NCT03619798) sponsored by Silver Lake Research, patient blood was tested using HemoType SC kits at the site of sample collection. The accuracy of the result was compared with the evaluation done in a laboratory in order to validate the use of HemoType SC as a diagnostic tool to be used where sample collection is performed.
Test sites were chosen based on healthcare resource availability. Children and adults from Ghana (low-resource), Martinique (moderate) and United States (high) were included in the study. Ghana also has a high prevalence HbS and HbC sub-types.
Participants included 383 from Ghana, 46 from Martinique, and 158 the U.S. The age range of the participants was newborn to 30 years; 16.6% of the participants from Ghana and Martinique were under one-month-old.
Overall, HemoType SC detected 99.5% of hemoglobin defect in the combined study population of 587 patients. Similarly, the test was 99.9% specific across all the participants, the team noted.
The test was 100% sensitive and specific in diagnosing sickle cell anemia, the most common and severe type of sickle cell disease.
“HemoTypeSC is an inexpensive, 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,” the authors concluded.