Episode 91. Haemotology with Dr Thomas Lew (Part 1)
Observed abnormalities in the full blood count are not uncommon, they may be transient and mild, often involving one cell lineage and most likely benign, or progressive involving more than one cell lineage and pointing us toward a condition requiring further investigation, possible referral and treatment.
In foetal life, haemopoiesis occurs in the yolk sac and later in the liver and spleen. After birth normal haemopoiesis is restricted to the bone marrow. Infants have haemopoietic marrow in all bones but in adults, haemopoietic marrow is found in the central skeleton and proximal ends of long bones. Expansion of haemopoiesis down the long bones may occur in bone marrow malignancy such as with leukaemia or when there is increased demand such as with chronic haemolytic anaemias . Both the liver and spleen can resume extra medullary haematopoiesis when there is marrow replacement such as in myelofibrosis or when there is excessive demand for example in severe haemolytic anaemia such as thalassaemia major. Incredibly the bone marrow produces more than 1 million red cells per second in addition to similar numbers of white cells and platelets .Common primitive stem cells in the marrow have the capacity to self replicate and give rise to increasingly specialised and committed progenitor cells. Myeloid progenitors differentiate into platelets, red blood cells, eosinophils neutrophils, basophils, macrophages, mast cells and dendritic cells. Lymphoid precursors differentiate into T cells (CD4 helper and CD8 suppressor) B cells (plasma cells and memory cells) and natural killer cells.
In conditions of disease or physiologic stress there may be a reduced number of cells in the full blood count assessment suggesting decreased production or loss (e.g. bleeding), sequestration (spleen, lymph nodes), or peripheral destruction. Elevated counts suggest an excess production which may be reactive (physiologic stress) or reflective of a primary abnormality of the bone marrow or other haemopoietic organs.
In this three part series we will explore common haematological abnormalities including anaemia, polycythaemia, the basis for neutropenia, neutrophilia, lymphopenia and lymphocytosis as well as thrombocytopenia and thrombocytosis.
Please join these interesting conversations with Dr Thomas Lew - haematology advanced trainee at the Peter MacCallum Cancer Centre with special interests in novel therapies for haematological disorders.
References:
Dr Thomas Lew: petermac.org
www.uptodate.com
To be a guest on the show or provide some feedback, I’d love to hear from you: manager@gihealth.com.au
Dr Luke Crantock MBBS, FRACP, is a gastroenterologist in practice for over 25 years. He is the founder of The Centre for GI Health, based in Melbourne Australia and is passionate about educating General Practitioners and patients on disease prevention and how to manage and improve their digestive health.