CPT® Code 86886

The indirect antihuman globulin test, commonly known as the Coombs test, is a laboratory procedure utilized to identify clinically significant antibodies present in a patient's blood. This test is particularly important in the context of blood transfusions, as it helps ensure compatibility between donor and recipient blood. In this test, certain red blood cells may become coated with complement proteins or IgG antibodies, which prevents them from agglutinating, or clumping together, when subjected to centrifugation. This phenomenon is referred to as IgG or complement sensitization. To facilitate agglutination, an additional antibody that reacts with the IgG or complement must be introduced into the test environment. The indirect antihuman globulin test is conducted on in vitro specimens, meaning that the blood sample is analyzed outside of the body. During the procedure, the specimen is incubated at a controlled temperature of 37 degrees Celsius, allowing the antibodies in the serum to interact with the red blood cells. Following this incubation, the cells are washed to remove unbound antibodies, and an antiglobulin reagent is applied to detect any antibody coating on the cells. The cells are then centrifuged, and the results of the test are interpreted based on the degree of agglutination observed. It is important to note that for qualitative testing performed on each reagent red cell, the CPT® code 86885 should be used, while CPT® code 86886 is designated for each antibody titer performed, which assesses the strength or potency of identified antibodies.