Anemia, Immune-Mediated

Anemia, Immune-Mediated



Basic Information image



Definition


Anemia resulting from a loss of erythrocytes caused by increased destruction by autoantibodies and complement.



Synonym(s)




• Autoimmune hemolytic anemia


• Immune-mediated hemolytic anemia (IMHA)



Epidemiology




• Acute anemia resulting from autoimmune attack by antibodies directed against erythrocyte membrane antigens.


• May be triggered by infection with Streptococcus fecalis. In these cases, immunoglobulin M (IgM) cold agglutinins clump red blood cells (RBCs) from normal horses when chilled.


• May occur in horses with lymphosarcoma and melanoma


Associated Conditions and Disorders


Thrombocytopenia (see “Thrombocytopenia, Immune-Mediated” in this section)



Clinical Presentation



History, Chief Complaint




• Pallor, weakness, depression, anorexia


• Anemia, lethargy, weakness


• Inappetence and anorexia


• Icterus


• Discolored urine (hemoglobinuria)



Physical Exam Findings




• Weakness and depression


• Pale mucous membranes


• Icterus


• Tachycardia


• Tachypnea or dyspnea


• Chronic anemia may result in cardiac dilation and development of a hemic murmur


• Pyrexia


• Splenomegaly


• Hemoglobinuria



Etiology and Pathophysiology




• Most cases are the result of apparently spontaneous production of anti-erythrocyte autoantibodies. These autoantibodies bind to erythrocytes and trigger their destruction.


• Some cases may be associated with infections or the presence of lymphoid neoplasia.


• Antibodies may target erythrocyte antigens directly (primary IMHA).


• Alternatively, antibodies may target modified erythrocyte membranes. These membranes may be modified by drugs or other infectious agents (secondary IMHA).


• Extravascular hemolysis may result in splenomegaly.


• Intravascular hemolysis may also occur.


• Liver and other organ damage may result from ischemia.

< div class='tao-gold-member'>

Related posts:

  1. Aggressive Stallion Behavior
  2. Aflatoxin Toxicosis
  3. Biliary Obstruction
  4. Cervix, Defects of

Stay updated, free articles. Join our Telegram channel
Tags:
Jul 24, 2016 | Posted by in SMALL ANIMAL | Comments Off on Anemia, Immune-Mediated

Full access? Get Clinical Tree
Get Clinical Tree app for offline access