Certified Pediatric Hematology Oncology Nurse (CPHON) Practice Exam

The Coombs test, also known as the antiglobulin test, is essential when autoimmune hemolytic anemia (AIHA) is suspected because it specifically detects antibodies that may be attached to red blood cells. AIHA occurs when the immune system mistakenly produces antibodies against the body’s own red blood cells, leading to their destruction. The Coombs test helps differentiate AIHA from other types of hemolysis by identifying these autoantibodies.

In cases of suspected AIHA, clinicians will perform the direct Coombs test to determine whether there are antibodies bound to the surface of red blood cells. A positive direct Coombs test indicates that the anemia is likely due to an autoimmune process, guiding further diagnostic and therapeutic decisions.

Although the blood type test, complete metabolic panel, and urinalysis can provide valuable information in managing a patient’s overall health or detecting other conditions, they do not specifically indicate the presence of autoantibodies against red blood cells, which is crucial for diagnosing AIHA. Thus, the Coombs test is the key laboratory test in this situation.