Blood is essential for life: it delivers all the oxygen and nutrients the tissues need and removes their wastes. The cellular components of blood—referred to as the formed elements—include red blood cells (RBCs), white blood cells (WBCs), and cell fragments called platelets. Plasma, which is mostly water, suspends the formed elements and carries within it everything that is water soluble (e.g., nutrients and electrolytes). Together, the plasma and formed elements circulate throughout the body as part of the cardiovascular system.

Blood disorders are often associated with disorders of the formed elements. Anemia is a blood disorder involving the abnormal synthesis of RBCs and/or hemoglobin. Anemia is quite common in the population due to a variety of causes.

In contrast, blood cancers – called leukemias – involve an inability to produce mature blood cells from the bone marrow. Leukemias involve the overproduction of abnormal, immature blood cells – called blasts – which crowd out and replace the growth an maturation of blood cells. Leukemias can be subclassified based on the blood stem cell that is abnormally proliferating (lymphoid vs myeloid stem cell) and whether the leukemia develops suddenly (i.e. acute) or long term (i.e. chronic)

From a health care perspective, blood tests are a common part of investigations. However, ‘blood tests’ are actually subdivided (like blood itself) into tests for either the number/quality of mature blood cells (e.g. hematology test will look at the number of RBC, WBC, and platelets) or tests for the content within plasma (E.g. chemistry test will look at amount of glucose and electrolytes within the plasma part of blood). Taken together, these test results can give signs of organ dysfunction, along with a snapshot of a person’s ability to carry oxygen, nutrients, electrolytes.

This chapter is subdivided into:

• Pre-test
• Normal blood production and function (including histology of normal bone marrow & peripheral blood)
• Classification of anemia and leukemia
• Pathophysiology and hematopathology of anemia and acute leukemia
• Interviews with health care professionals diagnosing/treating those with leukemia and discussions its complications
  • • Hematopathologist
    • Medical laboratory science technologists (hematology & clinical chemistry)
• Videotour of LifeLabs facility:  the largest processor of blood tests in Western Canada.
• Post-test

Abbreviations

The following abbreviations are used throughout the chapter.

ALL = acute lymphoblastic leukemia

Fe = iron

Hb = hemoglobin

Hct = hematocrit

LIS = laboratory Info system

MCH = mean cell hemoglobin

MCHC = mean cell hemoglobin concentration

MCV = mean cell volume

MLA = medical lab assistant

MLT = medical lab technologist

O2 = oxygen

PCR = polymerase chain reaction

ROI = region of interest

RBC = red blood cell

TIBC = total iron binding capacity

WBC = white blood cell