A new laser technology vastly improves pretransfusion testing, cutting blood incubation time from the current standard of five minutes to just 40 seconds. Developed by researchers at the Bioresource Processing Institute of Australia (BioPRIA), located within the Department of Chemical Engineering at Monash University — in conjunction with blood diagnostics manufacturer Haemokinesis Pty. Ltd. — the technology is the first of its kind and could bring pretransfusion testing out of the pathology lab and into point of care. Blood transfusion is a critical treatment for a variety of hematological conditions including cancer, bleeding trauma, childbirth, and major surgery. The new laser-aided system can better prevent fatal blood transfusions for critically ill patients, including casualties of mass trauma, and can even detect fetus-killing antibodies in pregnant women. “Laser incubation can be extremely valuable when time and accuracy [are] vital, especially in critical and emergency settings like mass trauma, where pretransfusion testing needs to be performed quickly in order to save lives,” said BioPRIA researcher Clare Manderson. The detection of immunoglobulin G (IgG) antibodies requires incubation at 37 °C, often for up to 15 minutes. Current incubation technology relies on slow thermal procedures such as heating blocks and hot-water baths. This delay adds to pathology costs and turnaround time, which can substantially affect a patient’s chance of survival. As part of the study, BioPRIA researchers developed the laser incubation model in which a targeted illumination of a blood-antibody sample in a diagnostic gel card is converted into heat by way of photothermal absorption. According to the researchers, the laser incubator heats the 75-μL blood-antibody sample to 37 °C in under 30 seconds. “[In the study] we show that red blood cells act as photothermal agents under near-infrared laser incubation, triggering rapid antigen-antibody binding with no significant damage to the cells or antibodies for up to 15 minutes,” Manderson said. “This study demonstrates laser-incubated immunohematological testing to be both faster and more sensitive than current best practice, with clearly positive results seen from incubations of just 40 seconds.” The researchers also explored the roles of incubation time and temperature of the IgG anti-D antibody and the Rh blood group system’s D antigen, which indicates the positive or negative attributed to a person’s ABO blood type group. Anti-D is the most common antibody. It’s present in a person’s plasma, and it's the biggest cause of hemolytic disease — a blood disorder that occurs when the mother’s and baby’s blood types are incompatible. According to the researchers, accurate testing for pregnant women’s antibodies is vital to saving the fetus or newborn. Clare Manderson with the new laser incubation technology. Courtesy of Monash University. “Giving blood transfusions to people isn’t as simple as giving O-negative to anybody,” Manderson said. "The ‘universal donor’ of O-negative blood can seriously harm a lot of people, or even kill them.” Blood group type is based on the presence of antigens on the surface of the red blood cell membranes, the researchers said, which consist of proteins, glycoproteins, glycophorins, glycolipids, and polysaccharide macromolecules forming roughly 346 known blood groups. Blood transfusion reactions are common if the recipient and donor aren’t correctly matched. “For the patient, it can mean that if there’s a critical blood loss scenario and they’re in desperate need of a transfusion, they need to have their blood group typed and antibody screened as quickly as possible,” Manderson said. “We’re aiming to bring that down to seconds instead of tens of minutes.” The research was published in Scientific Reports (https://doi.org/10.1038/s41598-019-47646-y).
