[New preparation method of C1 esterase for the dosage of its plasma inhibitor].

A purification method for C1 esterase is described. The final product significantly improved the sensitivity and the specificity of the enzymatic measurement of its plasma inhibitor C1-INH or alpha 2-neuraminoglycoprotein (alpha 2-NGP) by esterolysis of a synthetic substrate N-acetyl-L-tyrosine ethyl ester (ALTEe). A comparative study was done between the chromatographed C1 esterase and the native serum euglobulins: qualitative and quantitative determination of the serum contaminants, enzymatic activity measurement of C1-INH in normal subjects and in patients suffering from hereditary angioneurotic oedema (OANH) as well as in therapeutical C1-inhibitor concentrates.