Sickle Cell Anemia diagnosis and test

Early diagnosis of sickle cell anemia is very important because children who have the disease can receive proper treatment. Sickle cell disease is diagnosed when tests show hemoglobin S and other abnormal hemoglobin variants.

Tests commonly performed to diagnosed sickle cell anemia include:
Hb S solubility test. This test will detects the presence of hemoglobin S. A chemical is added to the patient’s blood sample that reduces the amount of oxygen it carries. In those who carry even one sickle cell gene, some hemoglobin S will be present. The reduced amount of oxygen will cause S-related polymers to form and the affected RBCs to sickle.

DNA analysis. This test is used to investigate alterations and mutations in the genes that produce hemoglobin components. It can determine whether a patient has one copy of the hemoglobin S gene, two copies, or copies of different hemoglobin variants. It may be performed for prenatal testing and confirm sickle cell trait status.

Hemoglobin electrophoresis. The hemoglobin electrophoresis test precisely identifies the hemoglobins in the blood by separating them. Patient’s blood sample is subjected to an electromagnetic field; different types of hemoglobin will migrate in patterns forming unique bands that enable a definitive diagnosis. In newborns with sickle cell, fetal hemoglobin F will predominate, but some hemoglobin S will also be present.

Complete Blood Count. The CBC gives important information about how many red blood cells are present, how much hemoglobin is in them, and give the doctor an evaluation of the size and shape of the red blood cells present.

Blood smear. Sickled cells and cell fragments can be seen on the blood smear. Doctors see a thin stained layer of blood on a slide under a microscope. The number and type of white blood cells, red blood cells, and platelets can be evaluated to see if they are normal and mature.

Iron studies. These may include: Iron, Ferritin, UIBC, TIBC, and Percent Saturation of Transferrin. These tests measure different aspects of the body’s iron storage and usage.

Prenatal Tests to diagnosis of sickle cell:
During pregnancy, doctors use amniocentesis or chorionic villus sampling (CVS) to see whether the fetus has sickle cell disease. Prenatal tests are available to determine if a baby will have sickle cell disease or sickle cell trait, an inherited condition in which both hemoglobin A and S are produced in the red blood cells, always more A than S. Sickle cell trait is not a type of sickle cell disease, but means that a person is a carrier of the sickle cell gene. When two people with sickle cell trait have a baby, their baby may inherit two sickle cell genes, one from each parent, and have the disorder.

Infant screening to diagnosis of sickle cell:
This tests is performed via the more sensitive Hb isoelectric focusing or HPLC fractionation. As the infant grows, The amount of Hb S will increase as F decreases. At about age 2, the amount of Hb S and Hb F stabilizes.

Adult screening to diagnosis of sickle cell:
This tests need a blood sample, which is screened for the presence of hemoglobin S, hemoglobin C, or thalassemia. When a member of couple has sickle cell disease, the other should be tested before planning to have a baby.

In certain tests, patients with sickle cell may be have abnormal results as follow:

• Decreased amount of oxygen in the blood
• CT scan or MRI may show strokes
• Elevated bilirubin
• High serum creatinine
• High serum potassium
• Peripheral smear show sickle cells
• Serum hemoglobin will be decreased
• Urinary casts or blood in the urine