It is characterized by an overproduction of one of the three components of blood: red cells, white cells, and plasma. As the cells rapidly reproduce, they crowd out healthy blood cells and plasma in the bone marrow.
People with primary myelofibrosis often have anemia caused by too few red blood cells, but they may also have elevated platelets and white blood cells. Symptoms typically begin in people who are over 50 years old, and men and women are affected in equal numbers.
It’s not known what causes primary myelofibrosis; although, roughly half of the people diagnosed with this rare disorder have a gene mutation that occurs on the JAK2 gene. But again, the role this mutation plays is unknown.
What is known is that primary myelofibrosis impacts the formation of red blood cells, and as damaged cells outnumber their healthy counterparts, scar tissue forms in the bone marrow. This further hampers red blood cell production.
Because symptoms vary from patient to patient, treatment must be targeted to the individual. Typically, blood transfusions are used to combat severe anemia. Bisphosphonates are used to ease bone pain in some patients, and for those who suffer from an enlarged spleen, removal of the spleen is often necessitated. Stem cell transplants can potentially reset the formation of red blood cells, but just as with spleen removal, it carries great risks, which must be compared to the potential benefits.