CPT® Code 85445

The CPT® Code 85445 refers to a laboratory test specifically designed to measure Heinz bodies, which are denatured hemoglobin structures found within red blood cells (RBCs). Heinz bodies are formed when hemoglobin undergoes damage due to various factors, including exposure to oxidizing agents, certain drugs derived from aniline, and specific enzyme deficiency syndromes such as NADPH deficiency, glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, and alpha thalassemia. Additionally, they may be associated with unstable hemoglobin variants, including hemoglobin H, Zurich, Koln, Seattle, and Gun Hill. This test is particularly useful in the evaluation of hemolytic anemias that are linked to RBC enzyme deficiencies. It may also be part of a diagnostic work-up when 'bite cells' are observed on a routine blood smear. Bite cells are formed when splenic macrophages remove hemoglobin, leading to damage of the RBC membrane. The presence of induced Heinz bodies can provide critical insights into conditions such as oxidative chemical ingestion, G-6-PD deficiency, alpha thalassemia, and certain unstable hemoglobin disorders. To perform this test, a blood sample is collected through a separately reportable venipuncture, after which acetyl phenylhydrazine is added to the whole blood to enhance the production of Heinz bodies. The sample is then examined using Supravital Stain and direct visualization techniques under a microscope to assess the presence of these bodies.