What does the CH50 assay measure?

What does the CH50 assay measure?

• A. RBC quantity needed to agglutinate 50% of antibody
• B. Complement needed to lyse 50% of RBCs
• C. Complement needed to lyse 50% of antibody-sensitized RBCs
• D. Antibody and complement needed to sensitize 50% of RBCs

Answer: (C)

The CH50 assay specifically measures the ability of the complement system to lyse a standardized number of antibody-sensitized red blood cells (RBCs). This test evaluates the efficiency of the classical complement pathway by determining the minimum amount of complement required to achieve 50% lysis of these sensitized RBCs. The presence of antibodies bound to the RBCs activates the complement system, leading to cell lysis, which is the basis for interpreting the assay results. In this context, the correct answer reflects both the necessity of antibody-sensitized RBCs and the role of complement in facilitating their lysis, thus providing insight into complement function and potential deficiencies in the classical pathway.

The CH50 assay specifically measures the ability of the complement system to lyse a standardized number of antibody-sensitized red blood cells (RBCs). This test evaluates the efficiency of the classical complement pathway by determining the minimum amount of complement required to achieve 50% lysis of these sensitized RBCs. The presence of antibodies bound to the RBCs activates the complement system, leading to cell lysis, which is the basis for interpreting the assay results.

In this context, the correct answer reflects both the necessity of antibody-sensitized RBCs and the role of complement in facilitating their lysis, thus providing insight into complement function and potential deficiencies in the classical pathway.