The Pesaro experience has shown that a significant group of patients
(11% of the entire Pesaro experience) develop long-term, stablemixed
chimerism after transplantation.This has been confirmed
by other groups.Mixed chimeric patients, despite a limited (even
20%) engraftment, achieve a functioning graft status characterized
by normal hemoglobin level, no red blood cell transfusion requirement,
no iron increment, and a limited—not clinically relevant—
erythroid hyperplasia.31 Thus, in chimeric patients, the genetic
disease is under a substantially complete clinical control, without
achieving complete eradication of the thalassemic hemopoietic
clones.