MPN Education and News

Besides pursuing with the clinical development of new treatments, an important goal of the MPN Team and the Clinical Research Center for MPNs is to educate physicians, patients, caregivers and the community at large about novel, promising MPN medications and findings from the latest clinical research studies. These studies are presented at the national and international hematology/oncology meetings, such as ASH, ASCO, and SOHO. From 2013 to 2017, we organized and hosted 5 annual MPN Patient Meetings at MD Anderson in collaboration with the patient support groups.

In addition, we periodically publish the newsletter Leukemia Insights on MPNs (recent issues are available in the gray panel below) to inform physicians and the broader community about the active clinical trials on MPN medications at MD Anderson.

Bone Anatomy

The bone comprises three tissues: compact bone, spongy bone, and bone marrow. Compact bone makes up the outer bone layer whereas spongy bone is located at the ends of the bones. Bone marrow is the soft, spongy tissue that is located at the center of most bones and has many blood vessels. There are two types of bone marrow: red and yellow. The red bone marrow contains hematopoietic stem cells that become red blood cells, white blood cells, and platelets (please see Figure 1; right panel).

Major Types of Blood Cells

Red blood cells (Figure 1) carry oxygen throughout our body. The protein within red blood cells that carries oxygen throughout the body is named hemoglobin and gives the bright red color to oxygenated blood. All our tissues need oxygen to function normally. The percentage of red blood cells in the blood is the hematocrit. Anemia occurs when the red blood cell counts decrease. Symptoms of anemia include fatigue and weakness. White blood cells include several different types (Figure 1). The 3 major types of white blood cells are lymphocytes, neutrophils, and monocytes. White blood cells play a major role in fighting infections. Infections are likely to occur when white blood cell counts are low. Platelets or thrombocytes (Figure 1) help control bleeding. Thrombocytopenia occurs when the platelet counts decrease.

Bone Marrow Aspiration and Biopsy

After numbing a small area of skin, a hollow needle (bone marrow needle) is inserted into the patient’s hip bone. A small amount of bone marrow, blood, and/or a small piece of bone with marrow are removed for examination under the microscope (biopsy). The bone marrow specimen that is removed during the procedure is sent to the pathology and cytogenetics/molecular laboratories. An expert pathologist examines the specimens under the microscope and characterizes the morphology and the appearance of the cells and the bone marrow (for example, Figures 3 and 4). The pathology results together with the clinical findings lead the physician to the correct MPN diagnosis, for example, essential thrombocythemia, polycythemia vera, prefibrotic/early myelofibrosis, or myelofibrosis.

Primary myelofibrosis (PMF) is characterized by bone marrow fibrosis (Figure 3), namely fibers progressively replace the bone marrow, a process that leads to low counts of the 3 main blood cell types and ultimately failure of the marrow to produce blood. PMF is the most aggressive MPN. Polycythemia vera (PV) is characterized by an elevated red blood cell mass, leading to a high hematocrit.  Essential thrombocythemia (ET) is characterized by high platelet counts and megakaryocytes (the precursors of platelets) in the bone marrow. ET is the most indolent MPN and has the best prognosis among MPNs.