(22nd May, 2014);The U.S. Food and Drug Administration (FDA) approved the Immucor PreciseType Human Erythrocyte Antigen (HEA) Molecular BeadChip Test (BeadChip Test), manufactured by BioArray Solutions Ltd. of Warren, New Jersey, the first FDA-approved molecular assay used in transfusion medicine to assist in determining blood compatibility. The assay can be used to determine donor and patient non-ABO/non-RhD (non-ABO) red blood cell (RBC) types in the United States.
The surfaces of RBCs display certain minor blood group antigens in addition to the major ABO blood group antigens. Some people develop antibodies (Abs) against non-ABO antigens after blood transfusion or pregnancy. This is especially seen in people with sickle cell anemia who may receive repeated blood transfusions. And these developed Abs can destroy RBCs after corresponding antigens transfusion.
This can be prevented by selecting blood that is better matched to the patient‘s non-ABO antigens.
The identification of RBC antigens has traditionally been performed by blood with reagents (antisera) that are specific for the antigens for which the blood is being tested. However, specific antisera may be scarce or unavailable.
But the BeadChip Test provides a new method, works by detecting genes that govern the expression of 36 antigens that can appear on the surface of RBCs. The test uses thousands of coded beads that bind with the genes coding for non-ABO RBC antigens that are present in a blood sample. A signal of light is generated from each bead that has captured a specific gene. Accompanying computer software decodes the light signals and reports which antigens are predicted to be present on the red cells based on the genes that are detected.
Karen Midthun, M.D., director of the Center for Biologics Evaluation and Research, FDA said, “The approval of the Immucor PreciseType HEA Molecular BeadChip Test provides an alternative to serological typing and may enhance patient care in certain situations.”
The FDA committee also concluded that the data provided reasonable assurance that the Immucor PreciseType HEA Molecular BeadChip Test is safe and effective for its intended use.
