Haptoglobin Test

The haptoglobin test is a medical laboratory test used to measure the level of haptoglobin in the blood. Haptoglobin is a protein produced by the liver that binds to free hemoglobin in the bloodstream, helping to remove it from circulation and prevent its loss through the kidneys.

Purpose of the Test

The primary purpose of the haptoglobin test is to help diagnose and monitor conditions characterized by hemolysis (breakdown of red blood cells), such as:

• Hemolytic anemia
• Sickle cell disease
• Thalassemia
• AUTOIMMUNE HEMOLYTIC ANEMIA

How the Test is Performed

To perform a haptoglobin test, a blood sample is typically drawn from a vein in the arm using a needle and syringe or a vacuum tube. The blood sample is then sent to a laboratory for analysis.

Interpretation of Results

The results of a haptoglobin test are usually reported as a concentration of haptoglobin in the blood, measured in milligrams per deciliter (mg/dL) or grams per liter (g/L). The normal range for haptoglobin levels varies depending on the laboratory and the individual's age, sex, and other factors. Generally:

• Normal haptoglobin levels: 30-200 mg/dL
• Low haptoglobin levels (<30 mg/dL): may indicate hemolysis or liver disease
• High haptoglobin levels (>200 mg/dL): may indicate acute phase reaction, inflammation, or infection

Clinical Significance

The haptoglobin test can be used in conjunction with other laboratory tests to help diagnose and monitor a range of conditions. For example:

• Low haptoglobin levels in combination with elevated lactate dehydrogenase (LDH) and indirect bilirubin may indicate hemolytic anemia
• High haptoglobin levels in combination with elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) may indicate acute phase reaction or inflammation

Limitations of the Test

The haptoglobin test has some limitations, including:

• Low sensitivity for detecting mild hemolysis
• Possible false-negative results in patients with liver disease or those taking certain medications (e.g., corticosteroids)
• Possible false-positive results in patients with acute phase reaction or inflammation