Would you give IV iron for low TSAT in patients with MDS anemia who are transfusion independent but on an ESA?  

Yes. The literature is replete with evidence that iron restricted erythropoiesis mitigates optimal responses to ESAs. It is overwhelmingly likely that an individual receiving erythropoietin or darbepoetin will enjoy longer intervals and dose reduction if the IRE is corrected. I administer a gram of ...