Difference Between Aplastic Anemia and Pancytopenia

Bone marrow sections from a 64-year-old male with pancytopenia.

Aplastic Anemia vs Pancytopenia

The bone marrow is a spongy tissue present inside bones like sternum, skull, ribs, pelvis, spine etc. It is responsible for blood cell production. Aplastic anemia is a rare condition in which the bone marrow is damaged and it stops producing new blood cells. As the bone marrow fails to produce new blood cells, there is decrease in all the elements of blood. This leads to pancytopenia. Pancytopenia is thus, the reduction in all the three elements of blood i.e. red blood cells, white blood cells and platelets. Pancytopenia is not a disease but a finding seen in diseases of the bone marrow. Pancytopenia is most commonly seen in aplastic anemia.

In aplastic anemia, our immune system attacks the healthy cells of bone marrow. It is triggered due to exposure to chemotherapy, radiotherapy (used in cancer); chemicals like benzene and insecticides. It is also caused due to infections like Hepatitis, Parvovirus and use of drugs like carbamazepine, chloramphenicol whereas pancytopenia is seen in conditions like aplastic anemia and megaloblastic anemia (due to vitamin B12/folic acid deficiency). Pancytopenia is also seen in cancers like acute myeloid leukemia which is a cancer of bone marrow and multiple myeloma which is the cancer of the plasma cells (a type of white blood cell). It is also seen in infections and in cases of enlarged/overactive spleen.

In both aplastic anemia and pancytopenia, symptoms develop due to the decreased blood cells. Decreased red blood cells causes anemia. Anemia is a reduced oxygen carrying capacity of blood. Blood contains red blood cells which carry oxygen. Patients develop weakness and breathlessness due to anemia. Decreased white blood cells causes frequent infections. Decreased platelets lead to easy bleeding from gums, etc and bruising. Patient may develop bleeding from the nose or rectum. If cancers cause pancytopenia, the patient develops enlargement of liver and spleen.
Tests like Complete blood count, Kidney function test, Liver function test, Electrolyte levels, Vitamin B12 and Folic acid levels are done to find the cause of pancytopenia. Chest X-ray, CT scan and sonograpy of abdomen are done to rule out other causes of pancytopenia. Bone marrow biopsy will help us confirm the cause of pancytopenia. In Aplastic anemia, biopsy shows hypocellular bone marrow i.e. blood cells are less and replaced by fat.

Treatment of Aplastic anemia includes supportive treatment by blood transfusion and antibiotics to control infections. Immunosuppressants drugs are used to suppress the activity of immune cells that damage the bone marrow. In young patients, bone marrow transplant is an option. Treatment of Pancytopenia depends on the cause. If Leukemia has caused the pancytopenia, treatment includes chemotherapy, radiotherapy and bone marrow transplant.

Summary

Aplastic anemia is a blood disorder in which the bone marrow is damaged affecting the blood cell production. The bone marrow stops producing new blood cells. It is caused due to exposure to chemotherapy, radiotherapy, infections, use of drugs etc. Tests like complete blood count and bone marrow biopsy will confirm the diagnosis. Treatment would include blood transfusion, antibiotics and immunosuppressants.
Pancytopenia is a reduction in blood elements like red blood cells, white blood cells and platelets. It is not a disease but a very common finding seen in diseases involving the bone marrow like aplastic anemia, megaloblastic anemia, multiple myeloma, acute myeloid leukemia, splenomegaly etc. Tests like CBC, Kidney Profile, Liver Profile, Electrolye levels, Vitamin B12/Folic Acid levels etc will help us diagnose the cause. Bone marrow biopsy will help to confirm the diagnosis. Treatment depends on the cause.

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