[Development of a serum lipoprotein A-I immunoassay method].

We developed an immunoturbidimetric assay method for lipoprotein A-I by treating sera with an anti-apo lipoprotein A-II and A-I antibody sequentially. The assay is sensitive to detect lipoprotein A-I as little as 155 mg/l with good precision. There was a good correlation in the level of serum lipoprotein A-I between the present assay and a conventional differential electroimmunoassay on ready-to-use plates (r = 0.947; p < 0.001). Reference intervals in normal healthy adults (n = 109) ranged from 284 to 736 mg/l. The values were significantly lower in patients with coronary artery disease than in normal subjects (p < 0.001). The present assay can be useful to analyze patho-physiologic events in various lipid disorders.