Abraham Klepfish1, Hananya Vaknine2, Ami Schattner3. 1. Blood Bank and Hematology Institute, Wolfson Medical Center and Sackler Faculty of Medicine Tel Aviv University, Holon, Israel. Electronic address: klepfish@zahav.net.il. 2. Department of Pathology, Wolfson Medical Center and Sackler Faculty of Medicine Tel Aviv University, Holon, Israel. 3. Hebrew University Hadassah Medical School, Jerusalem, Israel.