Aplastic anemia

Definition

Aplastic anemia is a condition in which the bone marrow does not make enough new blood cells. Bone marrow is the soft, fatty tissue in the center of bones.

Causes, incidence, and risk factors

Aplastic anemia results from injury to the blood stem cells. These are immature cells in the bone marrow that give rise to all other blood cells types. The injury causes a decrease in the number of every type of blood cell. These cells are the red cells, white cells, and platelets.

Aplastic anemia can also be caused by certain medical conditions such as pregnancy or lupus. Exposure to certain toxins or medicines, including chemotherapy, can also lead to aplastic anemia.

Symptoms

Symptoms result from the bone marrow not being able to make new blood cells. Symptoms may be severe from the start or gradually worsen over time.

Low red cell count (anemia) can cause:

Low white cell count (leukopenia) causes an increased risk of infection.

Low platelet count (thrombocytopenia) can result in bleeding. Symptoms include:

  • Bleeding gums
  • Easy bruising
  • Frequent or severe infections
  • Nose bleeds
  • Rash--small pinpoint red marks on the skin (petechiae)

Signs and tests

The health care provider will perform a physical exam.

Blood tests will show:

A bone marrow biopsy shows fewer-than-normal blood cells and an increased amount of fat.

Treatment

Mild cases of aplastic anemia may require no treatment. Symptoms are treated as needed.

If blood counts become lower, patients receive extra blood and platelets through transfusions. Over time, transfusions may stop working, resulting in very low blood cell counts. This is a life-threatening condition.

Bone marrow transplant or stem cell transplant may be recommended for patients under age 40. This treatment works best when the donor is a fully-matched brother or sister. This is called a matched sibling donor.

Older patients and those who do not have a matched sibling donor are given medicines to suppress the immune system. These medicines may allow the bone marrow to once again make healthy blood cells. But the disease may return (relapse). A bone marrow transplant with an unrelated donor may be tried if these medicines do not help or if the disease comes back after getting better

Expectations (prognosis)

Untreated, severe aplastic anemia leads to rapid death. Bone marrow transplant is very successful in young people. It is also used in older patients or when the disease comes back after medicines have been tried.

Complications

  • Severe infections or bleeding
  • Complications of bone marrow transplant
  • Reactions to medicines
  • Hemochromatosis (buildup of too much iron in the body tissues from many red cell transfusions)

Calling your health care provider

Call your health care provider or go to the emergency room if bleeding occurs for no reason, or if bleeding is hard to stop. Call if you notice frequent infections or unusual fatigue.

Figures

References

Bagby GC. Aplastic anemia and related bone marrow failure states. In: Goldman L, Schafer AI, eds. Goldman’s Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 168.

Young NS, Maciejewski JP. Aplastic anemia. In: Hoffman R, Benz EJ Jr, Silberstein LE, et al., eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 28.

Revision

Last reviewed 3/4/2013 by Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.

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