RAPID TEST FOR SCREENING SICKLE CELL DISORDERS
®​
FAQ
TOP QUESTIONS WE HEAR FROM PATIENTS
1. What is Sickle SCAN®?
Sickle SCAN® is a multiplexed qualitative point-of-care immunoassay used for the rapid diagnosis of Sickle SCAN® disorders. The test is made up of three indicators, which detect the presence of hemoglobins A, S and C, allowing the user to rapidly distinguish between normal, carrier and sickle cell samples.
2. What do I need to run Sickle SCAN®?
Sickle SCAN® test kit, which contains:
-
Sickle SCAN® Cartridges Capillary Sampler
-
Pre-treatment Modules (containing buffer)
-
Package Insert
Materials not provided but required:
-
Lancet
-
Alcohol wipes
-
GlovesTimer
3. How quickly can Sickle SCAN® yield results?
After the specimen and buffer mixture has been correctly dispensed into the Sickle SCAN® cartridge, allow the test to run for 5 minutes. *Test results that have run over 24 hours are invalid.
4. How accurate is Sickle SCAN®?
Specificity and sensitivity of Sickle SCAN® was evaluated by comparison with hemoglobin electrophoresis, one of the standard lab tests for sickle cell diagnosis. Results are shown below:
(Yang, Xiaoxi, et al. "A simple, rapid, low-cost diagnostic test for sickle cell disease." Lab on a Chip 13.8 (2013): 1464-1467.)
Sensitivity and Specificity of Sickle SCAN® Compared to Known Patient Genotypes
5. Does Sickle SCAN® only test for sickle cell anemia?
Sickle SCAN® tests for sickle cell trait, sickle cell anemia and HbSC disease.
Sickle Cell Trait: People with one sickle cell gene and one normal gene have sickle cell trait (SCT). SCT patients usually do not exhibit any of the symptoms of sickle cell disease (SCD), but have the potential to pass the trait onto their children. If both parents have SCT, there is a 25% chance their child will be an SCD patient.
Sickle Cell Disease: Sickle Cell Disease (SCD), an inherited blood disorder, often causes red blood cells to become sickle shaped through the presence of the abnormal hemoglobin S variant. The more rigid sickle-shaped blood may have difficulty passing through small blood vessels, blocking the normal blood flow, damaging tissues, and ultimately leading to many of the complications of Sickle Cell Disease.
HbSC Disease: HbSC Disease patients have hemoglobin C and hemoglobin S, which are both abnormal hemoglobins. HbSC disease is a milder sickling disorder, and symptoms are similar to that of SCD’s but are less frequent and less severe.
6. What do the results tell me?
A total of four detection lines are possible, with the control line appearing when the sample has been flowed through the cartridge. A blue line in that region will indicate the presence of hemoglobin variants A, S, and C greater than the limit of detection. The diagram below demonstrates the expected results of hemoglobin variants that the provider may encounter:
The HbA line may appear lighter, but no quantification is implied by the line intensity. The lightness of the line is caused by the antibody used in the making of the test.
7. Who is at risk for sickle cell disease?
Anyone could inherit the Hb S gene mutation, but it is more prevalent among those of African ancestry and those whose heritage traces back to the Mediterranean, South and Central American, the Middle East, India, and the Caribbean.
8. Who can use Sickle SCAN®?
Sickle SCAN® can be used by adults, and newborns more than 24 hours of age. But the optimum use for Sickle SCAN® would be during the initial visit for vaccinations.
9. Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed; however, testing should not be performed after a recent blood transfusion.
10. What are the alternatives?
Other tests typically used for the diagnosis of sickle cell disease are: hemoglobin electrophoresis, hemoglobin isoelectric focusing, hemoglobin fractionation by HPLC, and hemoglobin S solubility testing (not used for newborn screening, and does not diagnosis sickle cell trait or HbSC disease). With the exception of solubility testing, these tests need to be conducted in a lab setting, and because of the sample transportation, equipment, and technicians involved, these lab tests are much more costly and time-consuming than point-of-care tests.
