A new multi-institute study suggests the tick-borne alpha-gal syndrome(AGS) that can result in a chronic meat and animal byproduct allergy may complicate certain patients' ability to safely receive a blood plasma or platelet transfusion.
Dartmouth Hitchcock Medical Center (DHMC) pathologists Nancy M. Dunbar, MD, and Richard M. Kaufman, MD, were among the authors of the study that was published August 24, 2026 in JAMA Internal Medicine.
“We anticipate that this will change transfusion practices in the U.S., at least in AGS high-prevalence regions,” says Kaufman, who is the study's lead author and also a professor of pathology and laboratory medicine at Geisel School of Medicine at Dartmouth (Geisel). “DHMC has already taken the step to cease giving transfusions of B or AB platelets to O patients to avoid potential injury to these patients.”
AGS is a serious allergy transmitted by a sugar molecule called alpha-gal in the saliva of Lone Star ticks. First documented in 2025, the allergy is triggered by ingesting meat from mammals, such as beef, pork and lamb, as well as other products from these animals, like dairy and gelatin. An AGS reaction can trigger delayed, severe reactions like hives, stomach pain and anaphylaxis.
In recent years, DHMC has seen an uptick of patients with type O blood experiencing severe and even life-threatening allergic reactions after receiving platelets or plasma from type B or AB donors.
Dunbar and Kaufman had hypothesized that these patients may have pre-existing antibodies to alpha-gal from tick bites, and that hospitals in regions with higher concentrations of AGS patients, like DHMC, might also see an increase in allergic reactions in O patients receiving B or AB units. The international team of researchers then found that transfusion-related alpha-gal syndrome, or TRAGS, is a legitimate manifestation of AGS and should be taken into account in the safety practices of hospital transfusion services.
The study was carried out at 40 sites in five countries, where over 550,000 platelet and plasma transfusions were analyzed. Among the coauthors is also Anne G. Hoen, PhD, an associate professor of epidemiology, biomedical data science, and microbiology and immunology at Geisel.
For more information, read the Dartmouth Health press release.