Platelets are small anucleate fragments that are formed from the cytoplasm of megakaryocytes and have a characteristic discoid shape. To assemble and release platelets, megakaryocytes become polyploid by endomitosis and follow a maturation program that results in the conversion of…
Hemostatic, Hematopoietic, and Vascular Systems as a Functional Continuum Diseases affecting the bone marrow (BM) and peripheral blood are closely intertwined with the state of the vascular system, which acts as a niche, conduit, and regulator of blood cells. This…
Introduction Hemostasis preserves vascular integrity by balancing the physiologic processes that maintain blood in a fluid state under normal circumstances and prevent excessive bleeding after vascular injury. Preservation of blood fluidity depends on an intact vascular endothelium, and a complex…
Transfusion of red cells in all patients is primarily triggered by the need to increase oxygen delivery to tissues in the setting of blood loss or anemia. For patients with sickle cell disease (SCD), there are additional considerations for transfusion…
A variety of neonatal and pediatric patients require blood component transfusions. This chapter focuses on aspects of blood-bank laboratory testing, blood products and components, transfusion indications, and potential adverse events that are specifically relevant to neonates and children. Pediatric Blood…
Adverse reactions following blood transfusion reflect immunologic, pathophysiologic, and microbiologic events. This chapter presents information about transfusion-associated viral, bacterial, parasitic, and prion infections and discusses a number of emerging agents including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Transfusion-transmitted infection…
A transfusion reaction can be defined broadly as any adverse event that occurs in association with the infusion of a blood or cell therapy product. Transfusion reactions are classified by how close to transfusion they occur (timing), how much morbidity…
Therapeutic bloodletting is an ancient therapy that dates back to the Galenic conceptualization of illness caused by the imbalance of the four humors. The practice remained fashionable, albeit unproved, well into the 19th century. About the time that scientific skepticism…
Plasma and its derivatives are well-established clinical resources, but cost, risk of infectious disease transmission, although rare, and other adverse effects mandate their appropriate use. Even to this day, however, much still remains to be clarified regarding the appropriate clinical…
This chapter reviews human leukocyte antigen (HLA) and human neutrophil antigen (HNA) systems. A general background of the structure, function, and nomenclature of both systems and their relevance in clinical hematology is presented. Analysis of HLA gene products is applied…