29,751views
00:00 / 00:00
de completadas
de completadas
2024
2023
2022
2021
in anemia taxonomy p. 423
chloramphenicol p. 189
as drug reaction p. 249
Fanconi anemia p. 724
neutropenia with p. 429
thionamides p. 360
aplastic anemia p. 249, 427
aplastic anemia and p. 427
aplastic anemia p. 249
aplastic anemia and p. 249, 427
aplastic anemia p. 427
aplastic anemia p. 427
aplastic anemia and p. 427
aplastic anemia p. 427
aplastic anemia in p. 427
for aplastic anemia p. 427
aplastic anemia and p. 415
aplastic anemia p. 249
aplastic anemia p. 249
aplastic anemia p. 415
aplastic anemia as cause p. 427
aplastic anemia p. 249
aplastic anemia p. 427
aplastic anemia p. 429
in aplastic anemia p. 427
in aplastic anemia p. 427
Aplastic anemia is a pancytopenia, meaning all blood cell lines are decreased - so the term aplastic anemia, which just refers to low red blood cell count, is actually a misnomer.
So with aplastic anemia, there’s actually anemia, as well as leukocytopenia, or low white blood cells, as well as thrombocytopenia, or low platelet levels.
This condition takes many forms, ranging from mild to severe depending on the cause.
Now, blood cells are produced in the bones of the body, mainly in the bones of the pelvis, ribs and sternum, through a process called hematopoiesis.
This process starts in the bone marrow, the innermost portion of bone, where the hematopoietic stem cells reside.
These serve as progenitor cells for all the different cell types found in the blood.
First, hematopoietic stem cells, also called hemocytoblasts, can become lymphoid progenitors or myeloid progenitors.
The lymphoid progenitors can develop into lymphoblasts, which can then differentiate into some white blood cells like T-lymphocytes, B-lymphocytes, or natural killer cells.
The myeloid progenitors can differentiate into erythrocytes, or red blood cells, megakaryocytes, which eventually give rise to platelets, or myeloblasts, which can then become other white blood cells like monocytes, neutrophils, basophils, and eosinophils.
The most common cause of aplastic anemia is autoimmune destruction of hematopoietic stem cells.
The details of this mechanism are not fully understood, but research shows that there are alterations in the immunologic appearance of hematopoietic stem cells because of genetic disorders, or after exposure to environmental agents, like radiation or toxins.
This means that the hematopoietic stem cells start expressing non-self antigens and the immune system subsequently targets them for destruction.
As the immune system destroys hematopoietic stem cells a whole host of complications arise.
Due to the low red blood cell count tissues cannot properly oxygenate so the heart pumps harder to circulate the red blood cells leading to chest pain and shortness of breath.
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 © 2024 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.