Figure 3
Loss of CXCR4 expression on SLE B cells. (A) Membrane expression of CXCR4 on CD19+-gated PBMC from healthy and SLE subjects was determined by flow cytometry using the APC-conjugated 12G5 (empty histograms) or isotype control (filled histogram) mAb. Displayed data are representative plots of the mean fluorescence intensity (MFI) of CXCR4 at the surface of total B cells from a healthy individual and two patients with either inactive or active SLE. (B) The percentage of total (CD19+) B cells, naive (CD19+CD27-) B cells, memory (CD19+CD27+) B cells and PC (CD19lowCD27high) expressing CXCR4 in healthy and SLE subjects are given. Box plots show the median values, 25th and 75th quartile and the range of values. Kruskal-Wallis H test and associated P values are indicated. ***P < .0005 compared with control B cells (as determined using the Mann–Whitney U-test). (C and D) CXCR4-positive fraction (C) or MFI (D) values obtained within total B cells for each SLE patient were plotted as a function of SLEDAI scores. Correlation factor (r, Spearman’s) and P value are indicated.