1. From the Departments of Clinical and Experimental Medicine-Pediatrics, University of Ferrara, Ferrara, Italy; the Transfusion Service, Arcispedale Sant'Anna, Ferrara, Italy; the Ospedale Microcitemico and the Department of Biomedical Sciences and Biotechnology, University of Cagliari, Cagliari, Italy; the Prince of Wales Hospital, Randwick, NSW Australia; and the Division of Hematology, the Children's Hospital of Philadelphia, Philadelphia, PA.