Why do target cells form

Images show peripheral blood smears with numerous target cells present examples are indicated by arrows. Image 1: x oil immersion.

Image 2: 40x magnification. Image 3. Other target cells may also look folded or bell shaped. Note: The target cell membrane is thinner than normal cells. Liver Disease: membrane cholesterol concentration is reduced, decreasing the tensile strength of the membrane, resulting in target cell formation.

Artifact: Target cell formation occurs when blood smears are made when humidity is high. Hemoglobinopathies: There is a uneven distribution of hemoglobin within the cell, and an increased surface area to volume ratio.

Note: Target cells have an increased surface area to volume ratio and decreased osmotic fragility. The complete blood count and peripheral blood smear evaluation. In: Clinical laboratory hematology. New Jersey: Pearson; Variations in shape and distribution of erythrocytes. In: Clinical hematology atlas. These cells are seen in association with some forms of anemia, and following the removal of the spleen splenectomy.

Blood transports oxygen and nutrients to body tissues and returns waste and carbon dioxide. Blood distributes nearly everything that is carried from one area in the body to another place within the body.

For example, blood transports hormones from endocrine organs to their target organs and tissues. Blood helps maintain body temperature and normal pH levels in body tissues. The protective functions of blood include clot formation and the prevention of infection. The blood sample is sent to a lab. There, the lab technician looks at it under a microscope.

Or, the blood may be examined by an automated machine. When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away. This test may be done as part of a general health exam to help diagnose many illnesses. Or, your health care provider may recommend this test if you have signs of:. A blood smear may also be done to monitor the side effects of chemotherapy or to help diagnose an infection, such as malaria.

Red blood cells RBCs normally are the same size and color and are a lighter color in the center. The blood smear is considered normal if there is:. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

Presence of RBCs with an oval shape may be a sign of hereditary elliptocytosis or hereditary ovalocytosis. These are conditions in which RBCs are abnormally shaped. There is little risk involved with having your blood taken.

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others. Bain BJ. The peripheral blood smear. Goldman-Cecil Medicine. Philadelphia, PA: Elsevier; chap Kliegman RM, St. Blood disorders. In: Kliegman RM, St. Nelson Textbook of Pediatrics. Hereditary elliptocytosis, hereditary pyropoikilocytosis, and related disorders.

Textbook of Family Medicine.