Ten-year evaluation of homogeneous low-density lipoprotein cholesterol methods developed by Japanese manufacturers

Masakazu Nakamura, Isao Koyama, Hiroyasu Iso, Shinichi Sato, Mitsuyo Okazaki, Yuzo Kayamori, Masahiko Kiyama, Akihiko Kitamura, Takashi Shimamoto, Yoshinori Ishikawa
2010 Journal of atherosclerosis and thrombosis  
Aim: The risk index for atherosclerotic cardiovascular diseases in the Japanese metabolic syndromefocused health checkup program was changed from total cholesterol (TC) to low-density lipoprotein cholesterol (LDL-C). We discuss the validity of this change with respect to standardization. Methods: The beta-quantification procedure of the Centers for Disease Control and Prevention (CDC) uses the LDL-C reference value as a target. Clinical laboratories and commercial manufacturers use homogeneous
more » ... rs use homogeneous LDL-C methods for standardization. (A) For clinical laboratories, LDL-C in 648 samples requested from 108 hospitals was analyzed. (B) Manufacturers participated in the CDC/ Cholesterol Reference Method Laboratory Network LDL-C standardization protocol. The standardization was conducted with a performance follow-up for the 10-year period from 1998 to 2008 at 2-year intervals, 6 times. Results: (A) In clinical laboratories, acceptable LDL-C levels within 4% of the CDC's criteria remained 70.4%, 456 of 648 subjects. Negative maximum bias deviating from the LDL-C target value was 35.8%, 52.5 mg/dL, and positive maximum bias was 24.5%, 32.3 mg/dL. (B) For manufacturers, the standardization achievement rate of the analytical reagent/instrument/calibrator system in the last four standardizations from 2002 to 2008 remained on average 66.6%, far lower than the level required. Conclusions: The standardization achievement rate of homogeneous LDL-C methods was much lower than that of TC. TC should still be used as a risk index for atherosclerotic cardiovascular diseases. The standardization achievement rate of homogeneous LDL-C should be maintained at 100%, at least using samples with normal lipoprotein profiles. The accuracy and specificity of LDL-C should be further improved before practical and clinical use.
doi:10.5551/jat.5470 pmid:20885070 fatcat:m55exdzh35bafdmgfgmwrz6bby