CH50

The quantitative assay of hemolytic complement activity depends on the ability of the primary complement pathway to induce hemolysis of red cells sensitized with optimal amounts of anti-red cell antibodies. For precise titrations of hemolytic complement, the dilution of serum that will lyse 50% of the indicator red cells is determined as the CH50. This arbitrary unit depends on the conditions of the assay and is therefore laboratory-specific. 

Normal Range: Laboratory-specific U/mL

 Decreased with: >50-80% deficiency of primary pathway complement components in congenital or acquired deficiency. 

 

Normal in: Deficiencies of alternative pathway, complement components. 

 

Additional: This is a functional assay of biologic activity. Sensitivity to decreased levels of complement components depends on exactly how the test is performed. It is used to detect congenital and acquired severe deficiency disorders of the primary complement pathway.