A Glucose‐Dependent Panhemagglutinin

. An agglutinin was identified in the serum of a non‐transfused primiparous patient that reacted with all commercial red blood cells regardless of their antigenic makeup. The autologous control was negative. The agglutinin was directed against human red blood cells that had been incubated in media containing glucose and washed prior to testing. Red blood cells incubated in 2% glucose solution became agglutinable after 6 days at 4°C or after 2h at 37°C. These red blood cells gradually became non‐reactive when washed and incubated in saline at 37 or 4°C. At 22°C the titer of the agglutinin was 128 (score 64) in LISS and 64 (score 56) in saline. The agglutinin was denatured by 2‐mercaptoethanol, but remained active after 30 min of heating at 56°C. Among various mono‐ and disaccharides tested, glucose was the only sugar that selectively inhibited the reaction. The presence of such an agglutinin may cause confusion in a transfusion service laboratory by mimicking an antibody directed against a high incidence antigen.