Teachable moment in classrooms:
- cellular basis of life chapter – concept of one gene, one protein
- cellular basis of life chapter – concept of gene mutation leading to protein malfunction
- cardiovascular system chapter – formation of red blood cells by stem cells in red bone marrow
- respiratory system chapter – oxygen transport by hemoglobin in red blood cells
The news item: Recently the following report appeared online:
Lab-grown blood given to people in world-first clinical trial
It is hoped the blood could revolutionise care for people who need regular donations.
The report described the need for blood transfusion for repeated infusions such as those for sickle cell anemia patients, and the shortage of minor blood types for transfusion. The report briefly described the lifespan of the red blood cells, and the process of growing blood in the lab.
So, Why Do I Care?? Blood transfusion, the administering of blood or red blood cells into the vein of the recipient, is a life saver when the recipient lost lot of blood, or when the red blood cells of the recipient are being damaged because of a disease. As the transfused blood is derived from blood donors who are not always available to donate, the volume of donated blood can be so low as to create a blood shortage. It would be a great improvement if red blood cells could be “manufactured” on demand. That would make blood shortages obsolete. In the US 100,000 people suffer from sickle cell anemia.
Plain English, Please!!! First, let’s talk about why blood transfusion is a lifesaver clinical intervention, in general. We need red blood cells to transport oxygen from the lungs to all organs of our body. When blood loss or damage to red blood cells (like in sickle cell anemia) decrease the number of oxygen transporter cells, the organs do not receive enough oxygen for normal functioning. It’s like a fleet of trucks delivering bread to a store. If the trucks break down, the bread never get’s to the stores, and the functioning of the store will suffer. In this case the red blood cell trucks deliver oxygen to organs of the body. The most noticeable effect of oxygen deficit is on the skeletal muscles (loss of muscle strength) and on the nervous system (fatigue, tiredness). Restoring the number of red blood cells to normal helps to return the functioning of the body to normal. This why most transfusions do not transfuse whole blood, but only red blood cells.
Second, let’s talk about why sickle cell anemia patients need frequent blood transfusions. In sickle cell anemia patients the mutation of the globin protein of hemoglobin causes the red blood cells to change