Development and Validation of a Novel ECL Method for the Quantitation of Complement C3a/C3a desArg in Human Plasma

Complement system contains more than 30 proteins in plasma and on cell surfaces at high endogenous level. It plays crucial roles in both innate and adaptive immune responses. Complements act through proteolytic cascade pathways and produce enzymatically active molecules and biologic effectors, including anaphylatoxin C3a. The activity of C3a is inactivated rapidly in plasma within a few minutes after formation through removal of the C-terminal arginine by carboxypeptidases. Accurate measurement of C3a/C3a desArg in plasma can be challenging due to their high abundancy and the heat sensitive nature of complements, such as heat induced conversion of C3 to C3a and C3a desArg.

Accurate measurement of C3a/C3a desArg in plasma can be challenging due to their high abundancy and the heat sensitive nature of complements, such as heat induced conversion of C3 to C3a and C3a desArg. A novel electrochemiluminescence (ECL) immunoassay method was developed to overcome the technique hurdles and successfully validated for quantitatively measuring C3a/C3a desArg in human plasma samples.