Hematology (haematology) is the clinical study of blood, blood-forming organs, and blood diseases. Human blood is composed of ∼45% cellular components and ∼55% plasma and plays an essential role in transporting oxygen, regulating body temperature, and supporting the immune system.
The three major cellular components, comprising of red blood cells (RBCs, erythrocytes), white blood cells (WBCs, leukocytes), and platelets, are essential for understanding, predicting, diagnosing, and treating a variety of hematologic diseases and disorders. They include blood infections, blood cell cancers, genetic disorders, autoimmune issues, and complications related to transfusions and pharmaceutical interactions, such as chemotherapy.
Hematologists have a challenging role to play in the field of oncology. Major blood cancers, like lymphoma, leukemia, and myeloma, account for approximately 10 percent of all new cancer diagnoses. These cancers affect blood cell production or alter their behavior, which can be treated with hematology validation in addition to typical therapies including radiation, chemotherapy, immunotherapy, and stem cell transplantation.
Histological staining of blood and blood-related tissue has been the standard method of analysis in hematology since the late 19th century. Panoptic staining according to Pappenheim,1 and staining according to Giemsa, Wright and Leishman,1 have continued to be the standard techniques in hematological diagnostic procedures, with various chemical modifications made to improve staining differentiation or specificity.1 Historically, most hematological samples were analyzed manually. Today, most samples are analyzed using semi- or fully automatic staining systems capable of determining all parameters necessary for diagnosis. Pathological or suspect blood and bone marrow smears are then subjected to classical differential analysis using stains, in addition to an antibody or genetic analysis if indicated.