Haptoglobin is a serum glycoprotein that is produced mainly by hepatocytes. It functions to clear free hemoglobin from the circulation following its release from damaged red blood cells, thus preventing hemoglobin-mediated tissue damage. Clinicians frequently use haptoglobin as a biomarker for diagnosing conditions including liver disease, hemolytic anemia, and cancer. In addition, veterinarians test haptoglobin levels to assess the health of both domestic and commercial animals. We offer an extensive selection of haptoglobin antibodies, antigens, and ELISA kits, which we develop and manufacture in-house, using internal gold standard controls for validation. Many of our haptoglobin products are literature-cited and consistently feature among our top-sellers.

What is haptoglobin?

Haptoglobin is a tetrameric protein consisting of two α chains and two β chains, linked by disulfide bonds. It is encoded by the HP gene in the form of an α/β dimer, which is subsequently cleaved into its two separate components for reassembly into the mature protein. After leaving the hepatocytes and entering the circulation, haptoglobin captures any free hemoglobin it encounters to promote its clearance from the body. This occurs through binding of haptoglobin-hemoglobin complexes to CD163, a macrophage membrane protein belonging to the scavenger receptor cysteine rich (SRCR) domain family, resulting in CD163-mediated uptake of the complexes for endocytic lysosomal degradation. If free hemoglobin is allowed to accumulate, it can cause oxidative damage to cells and tissues, leading to various health issues.

What is the clinical relevance of haptoglobin?

Under normal circumstances, human haptoglobin levels are maintained at approximately 0.5 - 2.0 g/L. However, because haptoglobin is an acute-phase protein – meaning its concentration can increase or decrease by 25% or more during inflammation – changes in these levels are often indicative of a clinical condition. Elevated haptoglobin has been linked to conditions including ulcerative colitis, inflammatory bowel disease, and rheumatoid arthritis, as well as to heart attack, cancer, obesity, and severe infection. Decreased haptoglobin is known to be associated with liver disease, hemolytic anemia, and malnutrition, which are all characterized by the fact that red blood cells are destroyed more rapidly than they are produced.

Why might you perform haptoglobin testing in animals?

Haptoglobin testing in animals is performed for many of the same reasons as in humans – to help diagnose or monitor disease. Yet haptoglobin levels are also widely used as an indicator of animal welfare, especially for commercial animals like cows, pigs, and sheep. Factors such as diet, hygiene, transportation, and weaning-induced stress can all impact serum haptoglobin levels, making haptoglobin testing a useful tool for improving animal wellbeing.

High-quality products for detecting and quantifying haptoglobin

We have developed a broad selection of products for detecting and quantifying haptoglobin. These include monoclonal and polyclonal antibodies for detecting human, bovine, cat, and horse haptoglobin, raised in mouse, goat, and rabbit hosts, in addition to purified haptoglobin that can serve as a control or reference standard. We also offer ready-to-use sandwich ELISA kits for detecting haptoglobin in serum or plasma samples from human, bovine, cat, horse, mouse, pig, rat, and sheep, with further products to come in the near future.

Typical standard curve data for the Bovine Haptoglobin ELISA Kit (catalog #E-10HPT).

The quality of our haptoglobin products is reflected in a growing number of literature citations. For example, our Bovine Haptoglobin ELISA Kit was recently used for studying the side effects of vaccination against foot-and-mouth disease, where data suggested that success rates for artificial insemination could be increased by changing vaccine protocols. And our Human Haptoglobin ELISA Kit and Mouse Haptoglobin ELISA Kit both helped to identify haptoglobin as a possible diagnostic biomarker for tumors characterized by the accumulation of myeloid cells.