This article is more than 5 years old. Information may no longer be current.
FDA approves genetic test to assess blood compatibility
The FDA recently approved the first gene-based molecular assay to be used in transfusion medicine for determining blood compatibility.
The Immucor PreciseType Human Erythrocyte Antigen (HEA) Molecular BeadChip Test (BioArray Solutions Ltd.) can be used to determine donor and patient non-ABO/non-RhD (non-ABO) red blood cell types in the United States.
Karen Midthun
“The approval of the Immucor PreciseType HEA Molecular BeadChip Test provides an alternative to serological typing and may enhance patient care in certain situations,” Karen Midthun, MD, director of the FDA’s Center for Biologics Evaluation and Research, said in a press release.
The surfaces of red blood cells display minor blood group antigens in addition to the major ABO blood group antigens. Some patients develop antibodies to non-ABO antigens after transfusion or pregnancy; in particular, patients who receive repeated blood transfusions, such as those with sickle cell disease. The development of such antibodies can cause red blood cell destruction if red blood cells with the corresponding antigens are later transfused, according to the release.
Development of antibodies to non-ABO antigens can be prevented by selecting blood that is better matched to the patient’s non-ABO antigens. Additionally, when a potential transfusion recipient has a known antibody that causes red blood cell destruction, red blood cells that are negative for the corresponding antigen must be found.
The identification of red blood cell antigens has traditionally been performed by serological typing, which involves testing blood with antisera that are specific for the antigens for which the blood is being tested. However, specific antisera may be rare or unavailable, the release stated.
The PreciseType HEA Molecular BeadChip Test provides a novel method for determining non-ABO antigens on red blood cells by identifying genes that govern the expression of 36 antigens that can appear on the surface of red blood cells. The test uses thousands of coded beads that bind with the genes coding for non-ABO red blood cell antigens that are present in a blood sample. A light signal 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, according to the release.
A study was conducted to compare the typing results of the PreciseType HEA Molecular BeadChip Test with licensed serological reagents and DNA sequencing. The results demonstrated comparable performance between the methods.
The release stated, the product was brought before the FDA’s Blood Products Advisory Committee on March 18. After reviewing the relevant information, the committee concluded that the data provided reasonable assurance that the test is safe and effective for the molecular typing of HEA phenotypes in 35 blood group systems.