American Society of Hematology disorders of the hematopoietic, hemostatic, and lymphatic systems, and disorders of the interaction between blood and the blood vessel wall. An American hematologist has trained in a subspecialty program approved by the American Board of Internal Medicine or the American Board of Pediatrics, or has acquired a comparable education in the field by alternate means, and is Board Certified (or eligible) in the subspecialty of hematology. Diagnostic expertise of a hematologist A hematologist is expert in the investigation, diagnosis, and management of disorders of the aforementioned organ systems through the use of the medical history, physical findings, specialized clinical laboratory
Blood type Blood Transfusion in addition to the common ABO and Rh systems. Thus, in addition to the ABO antigens and Rh antigens, many other antigens are expressed on the RBC surface membrane. For example, an individual can be AB, D positive, and at the same time M and N positive (MNS system), K positive (Kell system), Le or Le negative (Lewis system), and so on, being positive or negative for each blood group system antigen. Many of the blood group systems were named after the patients in whom the corresponding antibodies were initially encountered. Transfusion medicine is a specialized branch of