Hp2-1 represents an intermediate phenotype between Hp1-1 and Hp2-2 in terms of functionality and disease association. While Hp1-1 offers superior antioxidant capacity and hemoglobin binding efficiency, Hp2-1 provides moderate protection. This has significant clinical implications, particularly in diabetes, where Hp2-1 carriers have lower cardiovascular disease risk than Hp2-2 individuals but higher risk than Hp1-1 carriers. Diagnostically, haptoglobin phenotyping via tests like the Haptoglobin Typing ELISA helps identify diabetic patients who might benefit from specific interventions, such as vitamin E supplementation. Haptoglobin testing also aids in diagnosing and monitoring hemolytic anemia and other conditions involving accelerated red blood cell destruction.

Common uses include metabolic studies, therapeutics research, IVD Assay standards, calibrators and controls, cardiovascular research, mass spectrometry, oxidative stress research.