Blood Disorders (Anemia, Leukopenia, and Thrombocytopenia)
Blood is a multifaceted body fluid and the medium through which essential nutrients are delivered to tissues throughout the body. On average, the adult human body contains more than 5 liters of blood. Blood flows freely through the veins and arteries because it is over half liquid plasma; the remainder of blood volume consists mostly of solid cells and cell fragments, which are suspended in the plasma (ASH 2011; Merck 2006; Alberts 2002; MedlinePlus 2012a; Dean 2005).
- Red blood cells, or erythrocytes, contain hemoglobin, an iron-containing protein responsible for transporting oxygen from the lungs to tissues (Merck 2006). Erythrocytes are continuously produced in bone marrow and survive about 120 days (MedlinePlus 2012a; Lledo-Garcia 2012; Dean 2005). Having an abnormally low number of erythrocytes or low hemoglobin is known as anemia (Merck 2006).
- White blood cells, or leukocytes, are cells of the immune system (Merck 2006). They are produced in bone marrow from hematopoietic stem cells and typically circulate for a much shorter period than red blood cells – from less than a day to a few weeks (Pillay 2010; MedlinePlus 2012a; ASH 2011; Rakel 2011; Franklin Institute 2013). Types of leukocytes include neutrophils, eosinophils, basophils, lymphocytes, and monocytes (Merck 2008a). Having an abnormally low number of these cells is known as leukopenia (MedlinePlus 2011c, 2012b).
- Platelets, or thrombocytes, are involved in the formation of blood clots (ASH 2011). They are not actually cells, since they lack a nucleus, but fragments of large bone marrow cells; the platelet lifespan is about 6 to 9 days. Having an abnormally low number of thrombocytes is known as thrombocytopenia (Arnold 2012; Dean 2005).
Conventional treatment of these blood disorders is often hindered by significant side effects, and in some severe cases, patients must undergo invasive procedures or take medications for the rest of their lives. However, emerging therapeutic technologies, such as gene therapy, may improve the outlook for anemia in the near future (Payen 2012; Raja 2012; Noe 2010; Montebugnoli 2011; Fossati 2010; Nienhuis 2012). Moreover, some blood disorders may be caused by conditions that are easily treatable, but often underappreciated. For example, in men, low testosterone can cause anemia, and testosterone replacement therapy has been shown to promote healthy red blood cell production in this population (Bachman 2010; Maggio 2013; Carrero 2012; Ferrucci 2006).
The three major blood disorders – anemia, leukopenia, and thrombocytopenia – will be examined in this protocol. Information as to the biology of these diseases and their conventional diagnosis and treatment will be presented; some emerging therapeutic strategies will be discussed as well. Nutritional factors play an important role in the health of the hematopoietic (blood) system, and the impact of dietary and lifestyle choices in will be described.