Bone Marrow Aplasia
Information on the causes, symptoms, and treatments for the deficiency of blood cell–producing components.
Symptoms and causes
Bone marrow aplasia is a disorder that leads to the loss or insufficiency of red bone marrow, responsible for producing blood cells, resulting in the inability to generate new red blood cells (erythrocytes), white blood cells (leukocytes), and platelets. This disease can be congenital or acquired.
This pathology can be classified into two types:
- Total bone marrow aplasia: production of erythrocytes, leukocytes, and platelets ceases entirely.
- Partial bone marrow aplasia: only affects the production of one or two types of blood components.
Bone marrow aplasia is a rare disorder that affects both sexes. Prognosis varies depending on patient characteristics, the degree of bone marrow involvement, and any complications that have arisen. Until recent years, patient outcomes were poor, but with current treatments, most cases can be cured.
Symptoms
The symptoms of bone marrow aplasia manifest as a consequence of the deficiency of the different blood cell types. The most frequent are:
- Anemia:
- Pallor
- Fatigue
- Headache
- Weakness
- Dizziness
- Palpitations
- Recurrent infections
- Oral ulcers
- Easy bruising or bleeding
- Severe hemorrhages (cerebral or gastrointestinal)
- Loss of appetite
- Lymphadenopathy (enlarged lymph nodes)
- Weight loss
- Petechiae: small red spots on the skin
- Splenomegaly: enlarged spleen
- Hepatomegaly: enlarged liver
Causes
Bone marrow aplasia is categorized according to its causes:
- Congenital bone marrow aplasia: the patient has a genetic alteration present from birth, usually inherited, which increases susceptibility to the disease and may also affect other organs. The most common disorders are:
- Fanconi anemia: causes bone marrow damage
- Shwachman-Diamond syndrome: affects bone marrow, pancreas, and bones
- Congenital dyskeratosis: leads to bone marrow insufficiency
- Acquired bone marrow aplasia: the most common form, developing over the course of life due to various factors, although in most cases the cause remains unidentified (idiopathic bone marrow aplasia). Known triggers include:
- Viral infections, mainly hepatitis
- Exposure to toxic agents (pesticides, chemicals, paints)
- Autoimmune disorders
- Certain medications
- Prolonged exposure to ionizing radiation
Risk Factors
Risk factors for bone marrow aplasia are similar to those that trigger the acquired form:
- Genetic predisposition
- Viral infections:
- Hepatitis A, B, and C
- HIV
- Epstein-Barr virus
- Parvovirus
- Cytomegalovirus
- Rubella
- Measles
- Mumps
- Varicella
- Exposure to toxic agents:
- Pesticides
- Paints
- Varnishes
- Ionizing radiation
- Microangiopathy: lesions in small blood vessel walls
- Hemophagocytic lymphohistiocytosis: excessive immune response damaging healthy cells
- Tumor lysis syndrome: rapid destruction of cancer cells releasing excess potassium, phosphorus, and nucleic acids into the bloodstream
Prevention
Bone marrow aplasia cannot be prevented, as the causes are unknown in most cases. Nonetheless, limiting exposure to pollutants and avoiding infectious diseases is recommended.
Which Specialist Treats Bone Marrow Aplasia?
Bone marrow aplasia is diagnosed and managed by Hematology and Hemotherapy specialists.
Diagnosis
Diagnosis of bone marrow aplasia includes the following tests:
- Complete blood count (CBC): provides information on the number of red blood cells, white blood cells, and platelets, allowing detection of deficiencies.
- Bone marrow biopsy: when CBC results are abnormal, a marrow sample is taken to assess the presence of a decrease in hematopoietic stem cells responsible for blood cell production.
Treatment
Treatment of bone marrow aplasia is based on two pillars:
- Supportive therapy: focuses on reducing symptoms
- Red blood cell or platelet transfusions
- Antibiotics
- Targeted therapy: if the cause of bone marrow aplasia is known, this treatment aims to correct it
- Immunosuppressive agents
- Hematopoietic growth factors, stimulating blood production
- In severe cases, transplantation of hematopoietic stem cells from a donor’s bone marrow
