Fig. 2

Detection of platelet autoantibodies with the quantitative FCIA assay. a Representative scatter plots of 6 types of microbeads (APC fluorescence) with increasing concentrations of antibodies (FITC fluorescence). b Calibration curve (solid line) and precision profiles (dashed line) of quantitative FCIA assay. A merged fitting curve was calculated by using the Log MFI values of six different types of microbeads with different fluorescence intensities (#1–6) and increasing concentrations of exogenous human IgG. CV: coefficient of variations. c Quantification of autoantibodies against different platelet glycoproteins by the FCIA. Diluted plasma samples from ITP patients containing autoantibodies against platelet GPIX (●), GPIb (■), GPIIIa (▲), GPIIb (▼) and P-selectin (◆) were evaluated by the quantitative FCIA. Autoantibody concentrations were calculated and curves were fitted. Significant correlations were found between diluted plasma samples and the autoantibody concentrations