Lab Test: Haptoglobin Level
- This protein is decreased when significant hemolysis occurs, but is not specific for indicating the type of hemolytic anemia.
- Adults: 16-220 mg/dL (0.16-2.2 g/L)
- Newborns: 5-48 mg/dL (50-480 mg/L)
- Ahaptoglobinemia is not uncommon in the neonate and may persist up to the age of 3 months in up to 90% of infants.
- Children, 6 months to 16 years: 25-138 mg/dL (250-1380 mg/L)
- Critical Values: <40 mg/dL
- Dissolution of hematoma - reduced serum haptoglobin concentrations are associated with the dissolution of organized hematomas and other hemorrhagic debris
- Infectious disease management - heptoglobin is an acute phase reactant protein; concentrations may rise 3 to 8-fold in response to acute or chronic bacterial or parasitic infection (including localized infections).
- Severe liver disease - reduced serum haptoglobin concentrations, in severe hepatocellular pathology, represent a primary deficiency state due either to failed hepatic haptoglobin biosynthesis or to depressed hepatocyte secretion of haptoglobin.
- Suspected blood transfusion reaction - low concentrations occur in association with these reactions
- Suspected hemolytic anemia - low concentrations occur in both intravascular and extravascular hemolysis, in erythroblastosis fetalis, and in hemoglobinopathies represented by sickle cell anemia and the thalassemias.
- A complete absence of free serum haptoglobin may be seen with intravascular hemolysis.
- A serum haptoglobin cut-off level of 0.2 g/L is considered useful in differentiating between primary and secondary hemolytic anemia.
- The serum haptoglobin test is used to detect intravascular destruction (lysis) of red blood cells (RBCs).
- Haptoglobins are glycoproteins produced by the liver and are powerful, free hemoglobin-binding proteins, which form a new complex that is rapidly catabolized. This results in a diminished amount of free haptoglobin in the serum and these decreases cannot be readily compensated for by normal liver production. As a result, the patient demonstrates a transient reduced level of haptoglobin in the serum.
- As an acute-phase reactant, serum haptoglobin concentrations display bidirectional changes during inflammation. Since inflammatory states often coexist with hemolytic conditions, serum concentrations should be interpreted concurrently with the serology findings of at least one other acute phase reactant not affected by hemolysis.
- Increased levels may indicate:
- Collagen-rheumatic diseases, infection (e.g., pyelonephritis, urinary tract infection, pneumonia), tissue destruction (e.g., MI), nephritis, ulcerative colitis, Neoplasia, biliary obstruction, major depression.
- Decreased levels may indicate:
- Hemolytic anemia (e.g., erythroblastosis, fetalis, autoimmune hemolytic anemias, sickle cell, paroxysmal nocturnal hemoglobinuria, drug-induced hemolytic anemia, or uremia), transfusion reactions, prosthetic heart valves, primary liver disease, hematoma, tissue hemorrhage, subacute bacterial endocarditis.
- A slight decrease in haptoglobin levels is noted in normal pregnancy.
- Ongoing infection can cause falsely elevated test results.
- Drugs that may cause increased haptoglobin levels include: androgens and steroids.
- Drugs that may cause decreased levels include: chlorpromazine diphenhydramine, indomethacin isoniazid, nitrofurantoin, oral contraceptives, quinidine, and streptomycin.
- Collect a venous blood sample.
- Avoid specimen hemolysis, which may alter test results.
- Apply pressure or a pressure dressing to the venipuncture site and assess the site for bleeding.
- Explain the procedure to the patient.
- Tell the patient that no fasting is required.
Indications & Uses
What To Tell Patient Before & After
MESH Terms & Keywords