Abstract
Anti-KANNO, encountered in 1991 at Fukushima Medical University Hospital, reacted unlike any other known antibody. The antibody and its high-frequency antigen are named after the first patient. We investigated the reactivity and clinical significance of anti-KANNO in the original two patients, and 12 subsequent cases identified by Red Cross blood centers in Japan's Yamagata and Miyagi Prefectures. Among the 14 patients, 13 were females with a history of pregnancy. Anti-KANNO has the characteristics of a high-titer, low-avidity (HTLA) antibody. It reacts with red cells treated with 2-aminoethylisothiouronium bromide (AET), so it can be distinguished from anti-JMH. As yet, there are no reports of hemolytic transfusion reaction (HTR) or hemolytic disease of the fetus and the newborn (HDFN) attributed to anti-KANNO. It appears that anti-KANNO is more likely stimulated by pregnancy than by transfusion, and is of low clinical significance, except to the extent that it complicates pre-transfusion testing. Further surveillance, investigation, and reporting of anti-KANNO are warranted.
