Laboratory Results that Confirm Diagnosis of Immune Hemolytic Anemia
Immune hemolytic anemia (IHA) is a condition in which the body’s immune system attacks red blood cells (RBCs) and causes them to be destroyed prematurely. The most common type of IHA is caused by antibodies that attach to the surface of the RBCs and cause them to be broken down. Diagnosis of IHA requires laboratory testing to identify the presence of antibodies and to determine the type of IHA.
Complete Blood Count (CBC)
A complete blood count (CBC) is a standard laboratory test used to measure the number of red and white blood cells and platelets in a sample of blood. In IHA, the CBC will show a decrease in the number of RBCs (anemia), an increase in the number of reticulocytes (immature RBCs) and an increase in the number of white blood cells.
Peripheral Blood Smear
A peripheral blood smear is a laboratory procedure in which a sample of blood is viewed under a microscope. In IHA, the peripheral blood smear will show the presence of spherocytes, which are abnormally shaped RBCs that are due to the destruction of RBCs by the immune system.
Direct Antiglobulin Test (DAT)
The direct antiglobulin test (DAT) is a laboratory test used to detect the presence of antibodies on the surface of RBCs. In IHA, the DAT will be positive, indicating the presence of antibodies on the surface of the RBCs.
Indirect Antiglobulin Test (IAT)
The indirect antiglobulin test (IAT) is a laboratory test used to detect the presence of antibodies in the serum. In IHA, the IAT will be positive, indicating the presence of antibodies in the serum.
Flow Cytometry
Flow cytometry is a laboratory technique used to measure the size, shape, and surface protein expression of cells. In IHA, flow cytometry can be used to detect the presence of antibodies on the surface of RBCs.
Immunofluorescence
Immunofluorescence is a laboratory technique used to detect the presence of antibodies on the surface of cells. In IHA, immunofluorescence can be used to detect the presence of antibodies on the surface of RBCs.
These laboratory tests can be used to confirm the diagnosis of IHA. A diagnosis of IHA should be strongly considered in any patient with a low RBC count and a positive DAT or IAT.
