00:00 / 00:00
Aplastic anemia is a condition characterized by pancytopenia, meaning decreased production of all blood cell lines, so red and white blood cells, as well as platelets. This condition can be inherited, when it occurs because of genetic mutations, as well as acquired, when it occurs because of external factors.
Let’s start by looking at the physiology of blood cell production, or hematopoiesis. This process starts in the bone marrow, which is the innermost portion of bone, where hematopoietic stem cells reside. These serve as progenitor cells for all the different cell types found in the blood, including white blood cells, which primarily function as the defense mechanism against infections; as well as red blood cells, which are essential to carry oxygen to the tissues; and platelets, which play a key role in blood clotting.
Now, hematopoietic stem cells reach their final, mature form, when they receive the appropriate signals in the form of specific growth factors or stimulating factors. One of these growth factors is called erythropoietin, or EPO. This is a hormone released by the kidneys, that tells hematopoietic stem cells to differentiate into red blood cells. Another important factor is the granulocyte colony-stimulating factor, or G-CSF, which is produced by various cells and tissues, including the bone marrow itself, and it stimulates the production of a specific group of white blood cells called neutrophils. Finally, there’s thrombopoietin, a hormone produced by the liver and kidneys, which stimulates platelet production.
Alright, now the causes of aplastic anemia can be inherited or acquired. The most common cause of inherited aplastic anemia is Fanconi’s anemia, a rare genetic disorder characterized by progressive bone marrow failure.
On the other hand, acquired causes of aplastic anemia include any other factor that leads to suppression or destruction of the bone marrow, including other conditions like an autoimmune disease, or undergoing treatments like chemotherapy or radiation therapy. Additionally, many cases are idiopathic, meaning the exact cause is unknown.
Some medications can also cause bone marrow suppression, like antiepileptics such as anticonvulsants hydantoins or carbamazepine; antithyroid medications like propylthiouracil and methimazole; and certain antibiotics like chloramphenicol and sulfonamides.
Aplastic anemia is a rare blood disorder caused by bone marrow failure to produce new blood cells. Even though it's referred to as aplastic anemia, it typically presents with pancytopenia, meaning that all three major blood cell lines - the red blood cells, white blood cells, and platelets are affected.
People with aplastic anemia may experience fatigue, shortness of breath, ecchymoses and mucosal bleeding, and frequent infections pallor Aplastic anemia can be caused by a variety of factors, including exposure to radiation or chemotherapy, viral infections, and autoimmune disorders.
Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.