Correlation of cDC expression of FcεRI with IgE.

<p>Expression of FcεRI and IgE on the surface of cDC was determined by flow cytometry. (A) Data are presented as fold MFI FcεRI versus fold MFI IgE expression, with non-sensitized subjects (n = 15) in red circles and sensitized subjects (n = 12) in black x's. Note the difference in the slope of the fitted lines (non-sensitized subjects in red dotted line; sensitized subjects in black solid line) above and below a fold MFI IgE of 12, suggesting that there is differential regulation of FcεRI on cDC around this level of cell bound IgE. For all subjects the data was fit with the following cubic equation (blue line): Ln(cDC FcεRI) = 2.26+0.72*ln(cDC IgE)-0.43*ln(cDC IgE)²+0.082*ln(cDC IgE)³); r = 0.86; p = 0.045. For equations based on sensitization status, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0032556#pone-0032556-t003" target="_blank">Table 3</a>. (B) Expression of cell bound IgE on cDC compared with serum (free) IgE levels. Data are presented as in (A) with fold MFI IgE expression versus serum IgE (kU/L). Note that a cell bound IgE fold MFI of 12 correlates with a serum IgE of around 38 (based on statistical fitting of the curve, this value could range between 34 and 42 kU/L).