So what if blood is thicker than water?

In this issue of Blood, Hulbert and colleagues prospectively look at a population of 40 patients with sickle cell disease (SCD) who were being regularly transfused for the prevention of recurrent stroke.They found an alarming incidence of stroke progression as well as development of new silent strokes.Progressive infarction occurred in almost one-half of the patients, 20% developed new overt strokes, and ϳ 27% developed new silent strokes despite aggressive transfusion therapy.