Aplastic anemia overview: Difference between revisions

Jump to navigation Jump to search
No edit summary
Line 20: Line 20:


==Differentiating [disease name] from other Diseases==
==Differentiating [disease name] from other Diseases==
*[Disease name] must be differentiated from other diseases that cause [clinical feature 1], [clinical feature 2], and [clinical feature 3], such as:
 
:*[Differential dx1]
:*[Differential dx2]
:*[Differential dx3]
==Epidemiology and Demographics==
==Epidemiology and Demographics==
===Age===
===Age===

Revision as of 18:44, 20 October 2018

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 overview On the Web

Most recent articles

cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Aplastic anemia overview

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 overview

CDC on Aplastic anemia overview

Aplastic anemia overview in the news

Blogs on Aplastic anemia overview

Directions to Hospitals Treating Aplastic anemia

Risk calculators and risk factors for Aplastic anemia overview

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.

Overview

Anemia is the condition of having fewer red blood cells than normal, or fewer than needed to function properly. Typically, anemia refers to low red blood cell counts, but aplastic anemia patients have lower counts of all three blood cell types: red blood cells, white blood cells, and platelets. Bone marrow is a sponge-like tissue inside the bones. It makes stem cells that develop into red blood cells, white blood cells, and platelets. Aplastic anemia is a condition where bone marrow does not produce sufficient new cells to replenish blood cells. The term 'aplastic' means the marrow suffers from an aplasia that renders it unable to function properly. Red blood cells carry oxygen to all parts of your body. They also carry carbon dioxide (a waste product) to your lungs to be exhaled. White blood cells help your body fight infections. Platelets are blood cell fragments that stick together to seal small cuts or breaks on blood vessel walls and stop bleeding. It's normal for blood cells to die. The lifespan of red blood cells is about 120 days. White blood cells live less than a day. Platelets live about 6 days. As a result, the bone marrow must constantly make new blood cells. If the bone marrow can't make enough new blood cells, many health problems can occur. These problems include arrhythmias, an enlarged heart, heart failure, infections, and bleeding. Severe aplastic anemia can even cause death.

Historical Perspective

Paul Ehrlich in 1988 made known the notion of aplastic anemia. He narrated the case of a pregnant lady, who died of bone marrow failure. In1904 Anatole Chauffard named this disorder aplastic anemia. In 1920s and 1930s Alice Hamilton and Harrison recognised bone marrow failure in workers who were exposed to benzene in the United States. In the late 1940s and early 1950s, an epidemic of aplastic anemia started showing up in people who were recieving chloramphenicol, and then aplastic anemia has been related to many classes of drugs generally used in medical practice. Neal Young from john hopkins in 1980s introduced an immunosuppressive regimen which proved to be very effective treatment for aplastic anemia.

Classification

Aplastic anemia may be classified according to blood cell counts into 3 subgroups, moderately severe aplastic anemia or non severe AA (nSAA), severe aplastic anemia (SAA), and very severe aplastic anemia(vSAA)

Pathophysiology

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.

Causes

Common causes of aplastic anemia include hepatitis, Epstein-Barr virus, cytomegalovirus, parvovirus B19, and HIV. Medicines, such as Albendazole, Cefadroxil, Chlorpromazine, chloramphenicol , Carbamazepine, Hydroxychloroquine, Methimazole, Orphenadrine, Oxcarbazepine, Phenytoin, Quinine, Phenylbutazone, Sulindac, Sulfadiazine, Sulfasalazine, Valganciclovir hydrochloride. Other causes include radiation, chemotherapy, toxins, such as pesticides, arsenic, and benzene, and metastasis to bone marrow. Less common causes of aplastic anemia are Lupus (SLE), rheumatoid arthritis, .pregnancy, Thymoma, and collagen vascular disease.

Differentiating [disease name] from other Diseases

Epidemiology and Demographics

Age

  • People of all ages can develop aplastic anemia.
  • Common in adolescents, young adults, and the elderly

Gender

Men and women are equally likely to develop aplastic anemia

Race

Aplastic anemia is two to three times more common in Asians

Risk Factors

Aplastic anemia is a rare but serious blood disorder. Common risk factors in the develpment of aplastic anemia are radiation treatment, drugs and toxin exposure, chemotherapy, PNH, and viral hepatitis. Less common risk factors are pregnancy, benzene, pesticides, rheumatoid arthritis and SLE.

Natural History, Complications and Prognosis

Aplastic anaemia has a mixed clinical course. Untreated aplastic anemia leads to rapid death, typically within six months. Complications following development of aplastic anemia are infections, bleeding and paroxysmal nocturnal hemoglobinuria. Graft-versus-host disease and graft failure are the possible complications following bone marrow transplant in these patients. Mild cases resolve on their own requiring little or no treatment. Well-matched bone marrow transplants from siblings have been successful in young individuals with a long-term survival rate of 80%-90%

Diagnosis

Diagnostic Criteria

Bone marrow biopsy is the gold standard test for the diagnosis of aplastic anemia, These findings on performing bone marrow biopsy are confirmatory for aplastic anemiahypoplasia with <20% cellularity, normal maturation of all cell line, fat cells and stroma in bone marrow space. Residual hematopoietic cells are morphologically normal and hematopoiesis is not megaloblastic.

Symptoms

Aplastic anemia is seen as a result of hypoplastic bone marrow causing pancytopenia (anemia, neutropenia, thrombocytopenia). The history and symptoms seen are secondary to these abnormalities.

Physical Examination

Common physical examination findings of aplastic anemia include pale color, short stature, dyspnea, petechiae ,Purpura, Ecchymoses, Jaundice, Pallor ,bruises. patients can present with, oral leukoplakia, pharyngeal ulcers, necrotizing gingivitis and tonsillitis.

Laboratory Findings

Patients with aplastic anemia have a hypoplastic bone marrow (<20% cellularity), pancytopenia (transfusion-dependent anemia, thrombocytopenia, and severe neutropenia), a low reticulocyte count, and a normal maturation of all cell lines.

Imaging Findings

  • There are no imaging study associated with aplastic anemia

Treatment

Medical Therapy

  • Treatments for aplastic anemia include blood transfusions, blood and marrow stem cell transplants, and medicines.[1]
  • These treatments can prevent or limit complications, relieve symptoms, and improve quality of life.
  • Blood and marrow stem cell transplants may cure the disorder in some people who are eligible for a transplant.
  • Removing a known cause of aplastic anemia, such as exposure to a toxin, also may cure the condition.
  • People who have mild or moderate aplastic anemia may not need treatment as long as the condition doesn't get worse.
  • People who have severe aplastic anemia need medical treatment right away to prevent complications.
  • People who have very severe aplastic anemia need emergency medical care in a hospital. Very severe aplastic anemia can be fatal if it's not treated right away.
  • Blood transfusions can help keep blood cell counts at acceptable levels.
  • Blood transfusions help relieve the symptoms of aplastic anemia, but they're not a permanent treatment.
  • Blood and marrow stem cell transplants may cure aplastic anemia in people who can have this type of treatment.
  • The transplant works best in children and young adults with severe aplastic anemia who are in good health and who have matched donors.
  • Older people may be less able to handle the treatments needed to prepare the body for the transplant. They're also more likely to have complications after the transplant.

Surgery

there is no surgical treatment for aplstic anemia.

Prevention

  • There are no primary preventive measures available for aplastic anemia.

References

  1. Gonçalves V, Calado R, Palaré MJ, Ferrão A, Morais A (February 2013). "Hepatitis-associated aplastic anaemia: a poor prognosis". BMJ Case Rep. 2013. doi:10.1136/bcr-2012-007968. PMC 3604385. PMID 23413287.