Mizutani Y, Yamada S, Inoue K, Abe A, Kubono K, Sakurabayashi I
Central Institute, Shinotest Corporation, Sagamihara.
Rinsho Byori. 1999 Jun;47(6):547-53.
Apo(a), the protein moiety of Lp(a), has size polymorphism that derives from the variable number of K4 type 2 repeats. We have developed three ELISA method with using monoclonal antibodies against the K4 type 2 repeats, the K4 type 5-protease domain, and the K5 protease domain of the apo(a) molecule. The commercial assay kits were correlated with the results from ELISA that utilized a monoclonal antibody against the K4 type 2 but indicated poor correlation with an ELISA method using anti Lp(a) K4 type 5-protease domain monoclonal antibody. Serum Lp(a) values were 1.8-fold overestimated by the commercial assay kits in samples with S4 type of the largest isoform, but our ELISA method in which the apo(a) K4 type 5-protease domain is used as labeled antibody and capture antibody was not affected by size polymorphism.
