Tick Bite Allergy Risks Blood Transfusions

A meat allergy linked to tick bites, known as alpha-gal syndrome (AGS), may pose new risks for patients requiring blood transfusions. Research published recently indicates that individuals with type O blood, who typically have universal compatibility, could suffer allergic reactions if they receive transfusions from type B or AB donors. This concern stems from the similarity between the alpha-gal sugar molecule and an antigen found on type B blood cells.

The study revealed that allergic reactions during transfusions were nearly four times more frequent in U.S. regions where AGS is highly prevalent. Specifically, type B blood donations in these areas showed a nine-fold increased risk of moderate to severe reactions in type O recipients. In contrast, areas with low AGS prevalence did not exhibit this heightened risk. Consequently, some healthcare facilities, such as Dartmouth Health Medical Center, have begun to halt transfusions of type B or AB platelets to type O patients.

Researchers emphasize that AGS develops when a Lone Star tick bite causes the immune system to react to alpha-gal, a sugar molecule present in red meats like beef, pork, and lamb. Symptoms can range from hives and swelling to life-threatening anaphylactic shock. Given the increasing proliferation of ticks due to climate change, health professionals anticipate further understanding and adaptation of medical practices to address tick-borne illnesses like AGS and their unforeseen consequences on patient care.