Aplastic anemia pathophysiology

Jump to navigation Jump to search

Aplastic anemia Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Aplastic anemia from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

Chest X Ray

CT

MRI

Echocardiography or Ultrasound

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Aplastic anemia pathophysiology On the Web

Most recent articles

cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Aplastic anemia pathophysiology

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Aplastic anemia pathophysiology

CDC on Aplastic anemia pathophysiology

Aplastic anemia pathophysiology in the news

Blogs on Aplastic anemia pathophysiology

Directions to Hospitals Treating Aplastic anemia

Risk calculators and risk factors for Aplastic anemia pathophysiology

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Priyamvada Singh, M.D. [2] Nazia Fuad M.D.

Please help WikiDoc by adding content here. It's easy! Click here to learn about editing.

Overview

Bone marrow is a spongy tissue, found within the spongy or cancellous portions of bones. It is higly vascularized and richly innervated Bone marrow is the primary site of hematopoiesis and is composed of hematopoietic cells, marrow adipose tissue, and stromal cells. The most defenitive feature in pathophysiology of aplastic anemia is loss of hematopoietic stem cells. It may be in the form of hematopoietic failure or immune mediated destruction of bone marrow. Drugs, chemicals, viruses, and different kind of mutations change the immunologic appearance of HSCs resulting in autoimmune destruction of marrow cells. AA may develop gradually into other hematologic disorder which include paroxysmal nocturnal hemoglobinuria [PNH], myelodysplastic syndromes [MDS] and acute myeloid leukemia [AML]). Clonal evolution in AA can occur due to mutations or cytogenetic abnormalities. The genes that are commonly found to be mutated are DMNT3A, ASXL1, BCOR, BCORL1, PIGA.

Pathophysiology

Physiology

The normal physiology of bone marrow can be understood as follows:[1]

.

Pathogenesis

Image yellow fat ladden marrow https://www.wikidoc.org/index.php/File:Aplasticanemia.jpg source:By Wmheric [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)] [Public domain], from Wikimedia Commons]

The most defenitive feature in pathophysiology of aplastic anemia is loss of hematopoietic stem cells.[2][3]

Pathophysiologic mechanisms that result in loss of HSCs and cause aplastic anemia include:

Hematopoietic Failure

Immune-mediated T-cell destruction of marrow

Clonal Evolution

  • AA may develop gradually into other hematologic disorder which include[3]
  • The genes that are commonly found to be mutated are
    • DMNT3A
    • ASXL1
    • BCOR
    • BCORL1
    • PIGA

Genetics

Genes involved in the pathogenesis of aplastic anemia include:[3]

  • HLA-DR15
  • CD4+ CD25+ FOXP3+ regulatory T cells
  • STAT3
  • TERT
  • TERC

Associated Conditions

Aplastic anemia is associated with following conditions:[4]

Gross Pathology

Aplastic anemia does not exhibit any gross pathology

Microscopic Pathology

In aplastic anemia bone marrow microscopy reveals hypo and even acellularity, adipose tissue and pale stroma.[3]

References

  1. Hays K (February 1990). "Physiology of normal bone marrow". Semin Oncol Nurs. 6 (1): 3–8. PMID 2406826.
  2. Bacigalupo A (2007). "Aplastic anemia: pathogenesis and treatment". Hematology Am Soc Hematol Educ Program: 23–8. doi:10.1182/asheducation-2007.1.23. PMID 18024605.
  3. 3.0 3.1 3.2 3.3 Brodsky, R. A. (2000). "Aplastic Anemia: Pathophysiology and Treatment". Journal of the National Cancer Institute. 92 (9): 754–754. doi:10.1093/jnci/92.9.754. ISSN 1460-2105.
  4. 4.0 4.1 Young, Neal S. (2002). "Acquired Aplastic Anemia". Annals of Internal Medicine. 136 (7): 534. doi:10.7326/0003-4819-136-7-200204020-00011. ISSN 0003-4819.