One does find a large number of immature red blood cells (regenerative anemia) because the body sends them into circulation prematurely to make up for those that are lost to the disease. (2ndchance.info)
These mutant parasites are able to survive and multiply inside immature red blood cells called reticulocytes, without making hemozoin. (sciencedaily.com)
«I tend to scrutinize reticulocyte [immature red blood cell] values,» Ashenden says, «to see if there are any signs of accelerated or decelerated reticulocyte production.» (scientificamerican.com)