S-Orosomucoid (ORM), also known as alpha-1-acid glycoprotein (AGP), is an acute phase protein produced mainly in the liver. It is a glycoprotein-rich biomarker that plays a central role in the body's inflammatory response and the transport of various drugs and hormones in the blood. ORM belongs to the so-called "acute phase reactants" and increases in inflammatory processes, infections and certain disease states.
What is the physiological function of Orosomucoid?
As an acute phase protein, orosomucoid is produced mainly in the liver as part of the body's defense system against damage and infection. Its concentration increases in inflammatory processes and acts as a regulator of the immune system by modulating the activity of immune cells. In addition to its function as an inflammation marker, orosomucoid also has an impact on the transport of certain drugs and hormones in the blood. It can affect drug metabolism and distribution, which makes it relevant in pharmacokinetic studies. In addition, the protein has been shown to have some anti-inflammatory and protective effects on tissues, which may help reduce the harmful effects of long-term inflammation.
- Acute phase reactant in inflammation or tissue damage, levels increase rapidly as part of the systemic response.
- Transport protein binds and transports drugs, steroid hormones and other molecules in the blood.
- Immunomodulatory effect affects the immune system by inhibiting certain inflammatory processes.
- Anti-inflammatory properties have a role in protecting tissues from excessive inflammation.
When is S-Orosomucoid analyzed in healthcare?
S-Orosomucoid is analyzed in healthcare as part of the assessment of inflammatory conditions and systemic diseases. As it is an acute phase protein that increases during inflammation, it can provide important information in the diagnosis and monitoring of both acute and chronic inflammatory diseases. Its levels are altered in several pathological conditions, including infections, autoimmune diseases and some malignancies.
Analysis of S-Orosomucoid can be particularly useful in cases where CRP and other inflammation markers do not provide a clear picture of the disease process. Since S-Orosomucoid has a slower dynamics than CRP, it can also be a valuable indicator in the evaluation of long-term inflammatory processes or disease progression.
S-Orosomucoid is also used as a marker of liver function, as it is synthesized in the liver and its levels can be affected by liver diseases. In nephrotic syndrome and other kidney-related diseases, changes in S-Orosomucoid levels can provide important information about protein losses and disease progression.
- Chronic and acute inflammation: E.g. in rheumatoid arthritis, systemic lupus erythematosus (SLE) and inflammatory bowel disease (IBD).
- Liver diseases: As it is produced in the liver and levels can change when the liver is affected.
- Renal effects: Especially in nephrotic syndrome where increased levels can be seen.
- Malignant diseases: As some cancers can affect the levels of acute phase proteins.
- Postoperative monitoring: Can be used to assess recovery and inflammatory complications.
Reference values and interpretation of S-Orosomucoid
Reference values vary depending on the laboratory but are usually between 0.6–1.2 g/L for healthy adults.
Elevated levels of S-Orosomucoid:
- Acute and chronic inflammatory conditions
- Infections
- Autoimmune diseases
- Trauma or surgery
- Certain malignant diseases
Low levels of S-Orosomucoid
- Severe liver disease, e.g. liver cirrhosis
- Reduced protein synthesis in malnutrition
- Nephrotic syndrome, where loss of plasma proteins via the urine can lower levels
Clinical relevance
Because S-Orosomucoid is a relatively stable biomarker of inflammation, it is often used together with other inflammatory markers such as CRP and S-Albumin for a more comprehensive assessment of the patient's inflammatory status. Unlike CRP, S-Orosomucoid increases more slowly in acute conditions and may be more useful in assessing long-term inflammatory processes.