DXM up-regulates the mRNA expression of FcγRIIa and FcγRIIb on in vitro–cultured monocytes. Magnetically isolated monocytes from untreated ITP patients were cultured in the presence of different concentrations of DXM for 16 hours and harvested for real-time RT-PCR. β-actin mRNA was used as a control. Relative mRNA level represents the FcγRIIa or FcγRIIb expression normalized by β-actin (FcγRIIa/β-actin, FcγRIIb/β-actin) in each cell culture with respect to the expression of FcγRIIa/β-actin or FcγRIIb/β-actin measured in untreated cells. *P < .05.