[Susan]

Erin, if you are referring to a recent flow cytometry test for percent of PNH clone, it is the WBCS which indicate the clone percent. Since RBCs are lost to hemolysis in all PNH patients, even if hemolysis is very minor or invisible ( no red/dark discoloration seen in urine), the pathologist only interprets using the WBCs affected.
Make sure a hematologist with a good PNH background reads the result for you, not uncommon for the inexperienced to misinterpret the data. You also want to have the test done at a facility which does PNH flow cytometry fairly often.

Since all PNH patients have an element of Aplastic Anemia (AA), it is relatively common for PNH patients to have reduced wbcs and platelets in addition to reduced rbcs from hemolysis and possibly from AA. The reticulocyte count and % will tell you if your marrow is producing enough rbcs. So will a bone marrow biospy but unless your counts are pretty low you may not need one.

Dr Rosse, retied from Duke calls PNH marrows "lazy." PNH patients are less likiely to develop empty ( nealy complete lack of cell production) AA marrow but it happens once in a while.