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Serum complementary activity titer
Last reviewed: 20.11.2021
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Normally, the titre of complementary activity in the serum of adults is 50-140 U / ml.
The complement titre in the serum assesses the activity of the terminal components of complement when it is activated by the classical and alternative pathways.
Any inflammatory process with an adequate immune response is accompanied by an increase in the complement titer. Decreased titer indicates a lack of complement and leads to a weakening of its opsonizing function and complement-dependent cytotoxicity, which contributes to the accumulation of immune complexes and leads to chronic inflammation. The increase in complement activity is characteristic for allergic and autoimmune processes. In severe anaphylactic reactions, the complement titer decreases, and in case of anaphylactic shock it can not be detected at all.
Changes in the complement titer in the blood serum for various diseases
Increase in
- Autoimmune diseases:
- rheumatoid arthritis;
- systemic lupus erythematosus;
- nodular polyarteritis;
- bacterial endocarditis;
- nonspecific infectious polyarthritis
- Acute bacterial infections
Decrease in the indicator
- The condition after severe operations, purulent inflammatory processes, sepsis, peritonitis, hepatitis, liver cirrhosis, immunocomplex diseases
- Chronic, sluggish bacterial infections
- Malignant neoplasms with metastases
- Multiple myeloma
- Treatment with cytostatics and immunosuppressants