The Complement CH50 blood test, also known as the Total Hemolytic Complement assay, evaluates the overall activity of the classical pathway of the complement system, an essential component of the immune response. This test measures the capacity of the complement system to lyse, or break down, red blood cells, providing valuable insights into the functional integrity of the complement pathway.
To conduct the CH50 test, a blood sample is collected and mixed with sheep red blood cells that have been coated with antibodies. If the classical complement pathway is functioning properly, the antibodies will trigger the complement proteins, leading to the lysis of the red blood cells. The degree of hemolysis is quantified and reported as a CH50 value. A normal CH50 value indicates that all components of the classical complement pathway are present and active.
Abnormal CH50 results can reveal various conditions. A low CH50 level suggests a deficiency or dysfunction in one or more components of the classical complement pathway. This could be due to genetic disorders, autoimmune diseases such as lupus, or chronic infections. Although rare, an elevated CH50 level can occur in certain inflammatory conditions. Often, the CH50 test is used alongside specific complement component assays, like C3 and C4, to provide a more comprehensive understanding of complement system activity.
The CH50 test is particularly useful for diagnosing and monitoring diseases involving the immune system, especially those with suspected complement deficiencies or dysregulation. Identifying abnormalities in complement activity helps healthcare providers understand the underlying causes of a patient's symptoms and develop targeted treatment strategies.