Th activation in congenital hypoplastic anemia.

The authors identified persistent Th activation in five of seven children (71.4%) diagnosed as having Fanconi's anemia or Diamond-Blackfan syndrome. Th reactivity was no longer present in one patient after bone marrow transplantation. Tests on family members and other patients with bone marrow dysfunctions of childhood showed no Th activation. Less than 1 percent of healthy children or blood donors had Th activation. Patients with a variety of hemolytic and hypoplastic conditions also had a low incidence of Th activation. However, 13.5 percent of cord blood specimens demonstrated Th reactivity. This study indicates that Th activation may be a red cell developmental marker present in congenital hypoplastic anemias and also expressed on newborn red cells.