A methodological reappraisal of total and high molecular weight adiponectin determination in human peripheral circulation: comparison of four immunometric assays.

BACKGROUND: Adiponectin, present in different multimeric forms in circulation, is increasingly used in clinical settings as a cardiometabolic marker. The development of several commercially available enzyme-linked immunosorbent assays (ELISA) has allowed for the widespread measurement of adiponectin in research as well as in clinical practice. The comparative performance of these assays is thus an issue of major relevance. METHODS: The analytical performance of four different ELISAs (LINCO, B-Bridge, SPIbio and ALPCO) was evaluated. Samples from 102 cardiac patients and 40 healthy subjects were tested using LINCO and ALPCO. The latter is able to measure the concentrations of multimers. For the multimer assay, an error propagation study was performed. A subset of subjects was tested by all four ELISAs for comparison purposes. RESULTS: Bland-Altman plots revealed differences between the results of the four ELISAs, mainly for ALPCO. However, a strong correlation between the different ELISAs (ALPCO, r=0.83; B-Bridge, r=0.98; SPIbio, r=0.91 vs. LINCO) was observed. Total adiponectin measured by LINCO showed a better association with cardiac disease [receiver-operating characteristic (ROC) curves] than total and high molecular weight adiponectin measured by ALPCO. CONCLUSIONS: The results of this study contribute to a better understanding of the methodological features of the several ELISAs, and help in the evaluation and comparison of the relative results.