How is the CH50 test performed?

The test is based on the capacity of an individual’s serum to lyse sheep erythrocytes coated with anti-sheep antibodies (preferably rabbit IgG). The individual’s serum is diluted until the minimum concentration is reached that 50% of the sheep red blood cells are lysed, and that concentration is recorded as the CH50.

What is a CH50 assay?

The CH50 is a screening assay for the activation of the classical complement pathway (Fig 1) and it is sensitive to the reduction, absence and/or inactivity of any component of the pathway. When antibody-coated SRBC are incubated with test serum, the classical pathway of complement is activated and haemolysis results.

What does a low CH50 test mean?

Low levels of total complement (total hemolytic complement: CH50) may occur during infections, disease exacerbation in patients with systemic lupus erythematosus, and in patients with immune complex diseases such as glomerulonephritis. Undetectable levels suggest the possibility of a complement component deficiency.

What does CH50 test for?

The CH50 functional test measures the function of the complete classical complement pathway, mediated by components C1 – C9. If this measurement is outside the normal range, then each of the nine different complement levels can be measured individually to look for hereditary or acquired deficiencies.

What is a normal CH50?

Adult reference range is 42 to 95 U/mL. A low CH50 suggests the possibility of a complement factor deficiency.

What is CH50 value?

The CH50 reflects the ability of serum complement to lyse sheep red blood cells (RBCs); its value is the reciprocal of the dilution of serum to lyse 50% of antibody coated sheep RBCs. Reduction of the CH50 occurs when individual complement component(s) are deficient or consumed.

Does low C4 mean lupus?

Complement C4 plays an important role in eliminating certain infections. The complement component 4 (C4) test is a simple blood test that measures the amount of complement C4 circulating in your bloodstream. A low level of C4 is associated with autoimmune diseases, such as lupus and rheumatoid arthritis.

What is a C3 and C4 blood test for?

Complement tests, most commonly C3 and C4, are used to determine whether deficiencies or abnormalities in the complement system are causing, or contributing to, a person’s disease or condition. Total complement activity (CH50) may be ordered to look at the integrity of the entire classical complement pathway.