Components of normal haemostasis The haemostatic mechanisms have several important functions: (1) to maintain blood in a fluid state while it remains circulating within the vascular system; (2) to arrest bleeding at the site of injury or blood loss by…
Radioactive isotopes must be distinguished from nonradioactive isotopes of the same element. The radioactive forms are usually referred to as radionuclides or radioisotopes. These terms are interchangeable and in this chapter, the latter term is used. Methods using radioisotopes have…
Acknowledgement The authors would like to acknowledge Kathryn Moss for her contribution to the HIV monitoring section. Principles of flow cytometric immunophenotyping The primary methods for immunophenotyping in the haematological setting are immunocytochemistry (described in previous editions of this book)…
Acknowledgement The major contribution of the late Dr David Swirsky to this chapter in previous editions of the book is gratefully acknowledged. Erythrocyte cytochemistry Siderocytes and sideroblasts Siderocytes are red cells containing granules of non-haem iron. They were originally described…
The haemoglobin molecule Human haemoglobin is formed from two pairs of globin chains each with a haem group attached. Seven different globin chains are synthesised in normal subjects; two, ε and ζ, are characteristic of the embryo and contribute to…
Assessing the likelihood of acquired haemolytic anaemia Haemolytic anaemia may be suspected from either clinical or laboratory abnormalities. Suggestive clinical features include anaemia, jaundice and splenomegaly. Other relevant clinical features that should be sought are a history of autoimmune disease,…
The various initial steps to be taken in the investigation of a patient suspected of having a haemolytic anaemia are outlined in Chapter 11 and the changes in red cell morphology that may be found in haemolytic anaemias are illustrated…
Red cells are typically removed from the circulation at the end of their lifespan of about 120 days. A shortened lifespan due to premature destruction may lead to haemolytic anaemia when bone marrow activity cannot compensate for the erythrocyte loss.…
Acknowledgements Many thanks indeed to Dr Malcolm Hamilton and Mrs. Sheena Blackmore, authors of this chapter in editions 10 and 11 of this series. The descriptions of metabolic pathways for cobalamin, folate and homocysteine were assisted by Hematology Basic Principles…
Iron metabolism The iron content of the body and its distribution among the various proteins are summarised in Table 9-1 . Most of the iron is present in the oxygen-carrying protein of the red blood cell, haemoglobin, the synthesis and…