An Overview of Pancytopenia

Pancytopenia is a descriptive term referring to the combination of low levels of all of the types of blood cells including red blood cells (anemia), white blood cells (leukopenia), and platelets (thrombocytopenia). Symptoms, which often occur due to the reduced levels of these cells, include fatigue, infections, and bruising.

There are a number of different conditions that can cause pancytopenia, including bone marrow diseases, some cancers, and some infections; chemotherapy treatment can also cause pancytopenia. The treatment options for pancytopenia depend on the specific causes and usually focus on increasing the levels of cells to improve symptoms while treating the underlying cause.

Blood Cells Affected by Pancytopenia

Pancytopenia refers to a deficiency in all three major types of blood cells. Specifically, these include:

• Red blood cells (RBCs): RBCs are the cells that bind and carry oxygen to the tissues of the body.
• White blood cells (WBCs): There are several types of WBCs that are further broken down into granulocytes (including neutrophils, eosinophils, and basophils), and agranulocytes (including lymphocytes and monocytes). These cells are responsible for fighting off infections, among other functions.
• Platelets: Platelets are responsible for blood clotting.

Describing Low Levels of Blood Cells

These terms are used for lower levels of blood cells:

• A low level of red blood cells is referred to as anemia.
• A low level of WBCs is referred to as leukopenia (you may hear of neutropenia, which refers to a low level of the particular type of WBC known as neutrophils).
• A low level of platelets is referred to as thrombocytopenia, such as immune thrombocytopenia, and chemotherapy-induced thrombocytopenia.

Formation of Blood Cells in the Bone Marrow or Hematopoiesis

Blood cells all originate from a single common type of cell in the bone marrow known as a hematopoietic stem cell (HSM) or pluripotential stem cell (meaning it has the "potential" to become many different types of cells). These cells divide and through a process called hematopoiesis become progressively more specialized into all of the blood cells in the body.

Lab Tests

Pancytopenia is usually diagnosed by looking at a complete blood count (CBC).

In pancytopenia, a CBC will show deficient levels of all the types of blood cells including:

• A red blood cell count of fewer than 4.2 million cells per microliter (ul) in women or less than 4.7 million cells/ul in men (This may also be described by a low hemoglobin level).
• A white blood count of less than 4,000 cells/ul (normal is between 4,000 and 10,000 cells/ul).
• A platelet count of less than 150,000 cells/ul (normal is between 150,000 and 400,000 cells/ul).

Causes

Pancytopenia may be caused by anything that interferes with the formation of blood cells in the bone marrow or blood cell availability in the bloodstream (such as if the cells are held in the spleen).

This may involve bone marrow destruction by toxins, bone marrow suppression (during chemotherapy), or the replacement of bone marrow by other cells resulting in the disruption of blood cell production, as can occur with some cancers. Blood cell destruction or suppression may occur from inflammation, infections, or autoimmune conditions.

Most of these conditions are acquired later in life, but a few are inherited and present from birth.

Some of the possible causes of pancytopenia include:

• Chemotherapy-induced bone marrow suppression
• Suppression by drugs other than chemotherapy drugs, from antibiotics to heart disease medications
• Infections, such as infectious mononucleosis, HIV, and sepsis
• Aplastic anemia
• Splenic sequestration (holding of blood cells in the spleen so they can't get to the rest of the body)
• Toxins and chemical exposure, such as exposure to arsenic or benzene
• Blood cancers in the bone marrow, such as leukemia, lymphoma, myeloma, or metastatic cancer to bone marrow
• Spread of some solid tumors to the bone marrow, especially breast cancer, prostate cancer, colon cancer, gastric cancer, and melanoma, which usually causes anemia followed by thrombocytopenia
• Myelodysplastic syndromes ("pre-cancerous" conditions of the bone marrow)
• Autoimmune disorders, such as lupus
• Radiation sickness
• Inherited syndromes, such as Fanconi anemia and Diamond Blackfan anemia

Most Common Causes

A 2016 study looked at 70 patients with pancytopenia. Among these patients, the most common causes were:

• Megaloblastic anemia: 41.4% of cases
• Aplastic anemia: 22.9%
• Hypersplenism (overactive spleen): 15.7%
• Leukemia: 14.2%

Together, these four causes accounted for 94.3% of cases.

Symptoms

Pancytopenia symptoms may include weakness or an enlarged spleen in addition to symptoms related to deficiency of specific blood cells. Some of these symptoms include.

• Symptoms related to anemia (a low red blood cell count): fatigue, rapid heart rate, and shortness of breath
• Symptoms related to a leukopenia or neutropenia (a low white count): fever and signs of infection such as a cough or pain with urination
• Symptoms related to thrombocytopenia (low platelets): easy bruising and heavy bleeding

Diagnosis and Evaluation

Pancytopenia may be noted on a complete blood count (CBC). A first step in evaluating low levels of all cells is to repeat the CBC. A peripheral blood smear is then done to look further at each of the different types of cells. If it appears that you have pancytopenia, the next step is often a bone marrow biopsy.

A bone marrow aspiration and biopsy looks at the components of bone marrow, which include hematopoietic stem cells (the cells that differentiate into all of the different types of blood cells), blood cells in various phases of maturation, and supplies used to make blood cells, such as iron and vitamin B12.

In addition to looking at B12 levels in the blood, special stains and tests are done on the cells to look for changes, such as chromosomal and gene changes, often found with leukemias.

Treatment

The goal of treating pancytopenia is to find and treat the underlying cause. If the cause is not known, or if the pancytopenia is expected, such as with chemotherapy, treatment is aimed at minimizing the symptoms related to the deficiency of blood cells. Some treatments that may be used include:

• Drugs that stimulate the bone marrow: For chemotherapy-induced neutropenia and some other causes, the growth factors Leukine, Neupogen, or Neulasta may be used to stimulate the formation of WBCs. For chemotherapy-induced anemia, there are also some medications that may be considered.
• Blood transfusions
• Immunosuppressive drugs if the cause is due to an autoimmune condition
• Bone marrow transplant or stem cell transplant

Prognosis

The prognosis of pancytopenia depends largely upon its cause. Thankfully, we now have treatments such as transfusions and stimulating factors to help with the specific blood cell deficiencies while the underlying condition is evaluated and treated.

A Word From Verywell

There are many potential causes of pancytopenia, but all carry risks. With pancytopenia, all types of blood cells are reduced, although reductions in some may be of more concern than others.