Determination of adiponectin in serum using a latex particle-enhanced turbidimetric immunoassay with an automated analyzer

BackgroundAdiponectin is an adipose-derived hormone that plays a role in regulating metabolic processes such as fat partitioning and lipid and glucose metabolism. Quantification of adiponectin is useful for obtaining information on metabolic syndrome, but there is no rapid method to measure adiponectin for clinical use.MethodsWe developed a rapid and sensitive latex particle-enhanced turbidimetric immunoassay (LTIA) using a latex bead-immobilized anti-adiponectin polyclonal antibody. The assay was performed on a Hitachi H7170 analyzer and evaluated for validity as a method to quantitate adiponectin, in parallel with the ELISA.ResultsDilution tests using LTIA showed linearity from 0.25 to 30 μg/ml. Within-run CV and total CV were obtained in the range of 0.8–1.9% and 1.1–2.0%, respectively. No interference was observed in the testing of specimens containing potentially interfering substances such as bilirubin, ditaurobilirubin, hemoglobin triglyceride, rheumatoid factor, type IV collagen, fibronectin, and complement factor (C1q). A strong correlation between LTIA and ELISA was confirmed (n = 30, r = 0.990, y = 0.95x + 0.39).ConclusionThe LTIA assay is applicable to quantitating the serum concentration of adiponectin. This assay is more convenient and faster than ELISA and suitable for clinical routine analysis.