Figure 3. Serum of MDS patients stimulates proliferation of CD34⁺ cells.

(A) CD34⁺ HPCs from umbilical cord blood were stained with CFSE and subsequently cultivated for five days in vitro in culture medium supplemented with 10% serum of individual patients or of healthy controls. Cell division history was monitored by residual CFSE-staining and dotted lines indicate five cell divisions. (B) Mean fluorescence intensities after five cell divisions were normalized to control samples. In each experiment, 57 MDS serum supplements and 17 control serum supplements were tested in parallel. Mean and standard deviation were calculated over measurements with three different cord blood samples (*p<0.05, **p<0.01, ***p<0.001).