Comparison of sensitivities to PEG-rHu MGDF and TPO of healthy and ET megakaryocytic progenitor cells.
▪, PBMNCs from healthy control subject exposed to PEG-rHu MGDF. (A) Number of megakaryocytic colonies per 4 × 104 PBMNCs in 0.1 mL medium as a function of cytokine concentration. (B) Number of megakaryocytic colonies expressed as percentage of maximum as a function of cytokine concentration. Concentration of MGDF at half-maximum colony number was 30 ng/mL. ▾, PBMNCs from healthy control subject exposed to rHu TPO. Concentration of TPO at half-maximum colony number was 27 ng/mL. ▴, PBMNC from ET patient (SW) exposed to PEG-rHu MGDF. Concentration of MGDF at half-maximum colony number was 2.3 ng/mL. MGDF sensitivity ratio (N/ET) = 13-fold greater than normal. ♦, PBMNCs from ET patient (SW) exposed to rHu TPO. Concentration of TPO at half-maximum colony number was 1.6 ng/mL. TPO sensitivity ratio (N/ET) = 16.9-fold greater than normal (experiment 262).
