What is haptoglobin?
Haptoglobin is an important protein in blood plasma and is mainly produced in the liver. It serves on the one hand as a transport protein for hemoglobin and on the other as a so-called acute phase protein:
Transporter for hemoglobin
Acute phase protein
Acute phase proteins are produced by the body as part of the defense against infection. They support the immune system and ensure that the infection cannot spread further. In addition to haptoglobin, there are around 30 other acute phase proteins.
When is haptoglobin determined?
In the past, haptoglobin was determined in paternity tests. There are three different subtypes of haptoglobin, which differ slightly in their structure. Which subtype someone has in their body is genetically determined. However, DNA analyses are now widely used to determine paternity.
Haptoglobin – normal value
As a rule, the haptoglobin level is determined in the blood serum. The patient does not have to be fasting for the blood sample to be taken. Depending on age and, in some cases, gender, the following standard values apply (in milligrams per deciliter):
|
female |
male |
|
|
12 months |
2 – 300 mg/dl |
2 – 300 mg/dl |
|
10 years |
27 – 183 mg/dl |
8 – 172 mg/dl |
|
16 years |
38 – 205 mg/dl |
17 – 213 mg/dl |
|
25 years |
49 – 218 mg/dl |
34 – 227 mg/dl |
|
50 years |
59 – 237 mg/dl |
47 – 246 mg/dl |
|
70 years |
65 – 260 mg/dl |
46 – 266 mg/dl |
As newborns only produce haptoglobin from the third to fourth month, other markers must be used if haemolysis is suspected.
When is haptoglobin low?
- Congenital enzyme defects (such as pyruvate kinase deficiency)
- Hemoglobinopathies (diseases with impaired formation of hemoglobin such as sickle cell anemia)
- Autoimmune diseases (such as systemic lupus erythematosus)
- Metabolic disorders (such as Zieve syndrome)
- Infectious diseases (such as malaria)
- Diseases of the small blood vessels (microangiopathies such as hemolytic uremic syndrome)
- Certain medications (such as penicillin, sulfonamides)
If haptoglobin levels are low, it is also essential to look at the liver values. They may indicate a functional weakness and thus a reduced formation of the plasma protein.
As a haemolysis marker, haptoglobin also helps to diagnose the rare but serious HELLP syndrome during pregnancy. In addition to haemolysis, this also leads to increased liver values and a reduction in blood platelets (thrombocytes). This dangerous triad can cause internal bleeding, among other things, and can cost the lives of both the child and the mother.
Haptoglobin is one of the acute-phase proteins and is released by the body during inflammation. However, it is not very specific. Therefore, if inflammation is suspected, other values such as C-reactive protein (CRP) are also determined.
In addition to inflammatory reactions, tumors and a build-up of bile (cholestasis) also cause acute phase proteins such as haptoglobin to be elevated in the blood count.
What to do if haptoglobin is increased or decreased?
Altered measured values are treated according to the cause, if possible.
Further tests are also necessary if the values are low. Rapid action is particularly important in HELLP syndrome. If a low haptoglobin level indicates severe anemia, blood transfusions may be necessary.
