In the previous post, we discussed the chemistry of the liquid part of blood (called serum). By contrast, the CBC (complete blood count) evaluates the cellular components. There are many cell types that circulate in the blood but they are broadly grouped into three categories; red cells, white cells and platelets. These cell types are produced in the bone marrow or lymphatics then move into the blood stream.
The red cell (rbc) resembles a tiny, dried apricot, a shape that allows it to fold and contort while squeezing through the small capillaries. Red cells carry oxygen to the tissues and remove carbon dioxide. Oxygen is carried on a molecule called hemoglobin (Hgb) which contains iron. Normal hemoglobin levels range from 11 to 16 g/dl. Vitamins B12 and folate are also found inside the rbc and contribute to its function.
A red cell’s size is referred to as the mean corpuscular volume (MCV). A normal MCV is between 80-100 fL. Microcytosis (small cell size) occurs when the MCV is low and generally indicates iron deficiency. Only 10% of ingested iron is absorbed, therefore, slight changes in daily iron loss may quickly lead to deficiency. Like calcium, iron absorption is enhanced by stomach acid. Neutralizing acid with medications like proton pump inhibitors (Prevacid, Prilosec, etc), may further reduce iron absorption and add to deficiencies.
Enlarged cell size, called macrocytosis, may be caused by the effect of alcohol on the bone marrow, certain medications, B12 or folate deficiencies and some cancers. Big, round, red cells have trouble fitting through the small openings in blood vessels. This may cause a blockage that prevents flow of food and oxygen to the tissues.
A reduction in red cell number is called anemia and may arise from blood loss, iron deficiency, vitamin deficiency or abnormal bone marrow function. Conversely, a high red cell count is called polycythemia and is often seen in people with chronically low oxygen and in a disease called Polycythemia Vera.
Sickle cell anemia is due to a genetic defect in the hemoglobin molecule. When oxygen levels are low, the cell crumples into an inflexible, elongated, crescent shape. The resulting “log jam” of cells blocks capillaries and prevents the flow of food and oxygen.
White blood cells (wbc) are the body’s defense system against disease. Like our armed forces, there are several varieties of white cells which specialize in different forms of combat. However, the two major types are neutrophils and lymphocytes.
Neutrophils make up about 60-70% of circulating white cells and are important in fighting bacterial infections. Lymphocytes are the next most abundant cell type at 30-40% and they principally fight viruses. White cells may increase in response to infection or with cancers of the blood such as leukemia or lymphoma.
Platelets are an important part of the clotting process. They recognize areas of irregularity in the blood vessel wall (such as a cut) and bind there forming clumps. With the addition of clotting factors, they slow then stop blood flow. Aspirin irreversibly inhibits the clumping function of platelets and may lead to easy bruising or bleeding. When platelets are very low, uncontrolled bleeding may occur.
Healthy Habits for Good Immune Cell Function:
1. Wash your hands frequently, especially before eating.
2. Avoid putting your fingers in your eyes, nose or mouth as they are the prime portals of entry for viruses and bacteria. The majority of these foreign invaders are delivered to the body, on our hands.
3. Cover your mouth and nose when you cough or sneeze.
4. Consume at least 500 mg of Vitamin C daily. Vitamin C is important to the cells of immunity.
5. Regularly consume anti-oxidants (found in fruits, vegetables and fish) as they reduce immune cell damage and augment cell function.
6. Eat the “colors of the rainbow” as anti-oxidants are found in many food pigments.
7. Exercise regularly. Studies have shown an improvement in immune cell function in those who exercise.
8. If you are taking iron supplements, they should be taken with acidic foods (like orange juice) and before antacid medication.
9. If you are on daily aspirin and develop easy bruising or bleeding, stop the aspirin for a few days then resume at a lower dose or take it less frequently (i.e. every other day).
10. If you are scheduled for a surgical procedure, it is wise to stop aspirin or other anti-inflammatories (Advil and Aleve) one week before the procedure to allow the platelets adequate time to recover. This will reduce the risk of bleeding complications.