An anonymous reader writes "A woman in need of a lung transplant got her new lungs from someone with a peanut allergy who died of anaphylactic shock. Seven months after the surgery, the woman was at an organ transplant support group when she ate a peanut butter cookie and had a violent allergic reaction. So how had the woman's new lungs brought along a peanut allergy? A blog post dives into the medical details and explains that immune cells in the donated lungs couldn't have lived in the new body for long enough to cause the reaction... however, if they encountered an allergen (i.e. something peanuty) shortly after being transplanted, they could have trained the woman's native immune cells to respond."