This code system http://hl7.org/fhir/v2/0933 defines the following codes:

CodeDisplayComments
2RCDouble Red Cells
GRNGranulocytes
HEMHemachromatosis
HPCHematopoietic Progenitor CellsStem Cells and other cells classified as Hematopoietic
LYMLymphocytes
PLSPlasma
PLTPlatelets
PNPPlatelets and Plasma
PNRPlatelets and Red Cells
PPRPlatelets, Plasma, and Red Cells
THATherapeutic Apheresis
THWTherapeutic Whole Blood
WBLWhole Blood