Before this new research, the only way to determine if someone was Vel-negative or positive was with tests using antibodies made by the few people previously identified as Vel-negative following their rejection of transfused blood. Not surprisingly, these antibodies are vanishingly rare and, therefore, many hospitals and blood banks don't have the capacity to test for this blood type.
"Vel blood is one of the most difficult blood types to supply in many countries," the scientists write, "This is partly due to the rarity of the Vel− blood type, but also to the lack of systematic screening for the Vel−type in blood donors."
In response, the UVM and Paris researchers developed two fast DNA-based tests for identifying Vel-negative blood and people. These tests can be easily integrated into existing blood testing proceduresand can be completed in a few hours or less.
"It's usually a crisis when you need a transfusion" says Ballif. "For those rare Vel-negative individuals in need of a blood transfusion, this is a potentially life-saving time frame."
To make their discovery, Arnaud and coworkers in Paris used some of the rare Vel-negative antibody to biochemically purify the mystery protein from the surface of human red blood cells. Then they shipped them to Ballif in Vermont.
The little protein didn't reveal its identity easily. "I had to fish through thousands of proteins," Ballif says. And several experiments failed to find the culprit because of its unusual biochemistryand pipsqueak size. But he eventually nabbed it using a high-resolution mass spectrometer funded by the Vermont Genetics Network. And what he found was new to science. "It was only a predicted protein based on the human genome," says Ballif, but hadn't yet been observed. It has since been named: Small Integral Membrane Protein 1, or
|Contact: Joshua Brown|
University of Vermont