Frequently Asked Questions:

1What is warm antibody autoimmune hemolytic anemia (AIHA)?
Autoimmune hemolytic anemia (AIHA) is a rare, serious blood disorder in which the immune system produces antibodies that result in the destruction (hemolysis) of the body's own red blood cells (RBC). Approximately 1 in 100,000 adults are diagnosed with AIHA each year and this condition can create a severe, debilitating anemia.

In AIHA the body destroys RBCs at a greater rate than it can produce new RBCs, eventually leading to anemia (low levels of red blood cells), with symptoms such as fatigue, pale color, rapid heartbeat, and shortness of breath. In severe cases fever, chest pain, fainting, or heart failure may occur. Mild splenomegaly (enlargement of the spleen) is typical.

Warm antibody AIHA refers to the presence of antibodies that react with the red blood cell surface at body temperature. It is the most common form of AIHA, and can be either primary or secondary to an underlying disease such as systemic lupus erythematosus (SLE) or a lymphoproliferative condition such as or chronic lymphocytic leukemia (CLL) or lymphoma.

Some people with AIHA also have a similar condition, immune thrombocytopenia (ITP), in which the body attacks its own platelets—this combination of both conditions is known as Evans syndrome.

2How is warm AIHA diagnosed?
Patients with unexplained signs of anemia such as low hemoglobin may have a number of blood tests to confirm a diagnosis of warm antibody AIHA. These include:

  • Direct antibody (Coombs) test (DAT) positive for immunoglobulin G (IgG) antibodies. A positive DAT is a key signature of warm antibody AIHA.
  • Some or all of the following indicators of active red blood cell destruction/hemolysis: elevated lactate dehydrogenase, decreased haptoglobin, increased indirect bilirubin, and increased reticulocytes (immature red blood cells).
3What are the current treatment options for warm AIHA?
Treatment for AIHA varies widely, depending on medical need. A corticosteroid (such as prednisone) is the standard first line treatment initially given to patients. For patients that do not respond to corticosteroids, second line procedures/treatments include splenectomy (removal of the spleen), rituximab infusion, infusion of intravenous immunoglobulins (IVIG), erythropoietin, and/or danazol.

For patients with severe AIHA without a response to other treatments, immunosuppressive agents such as cyclosporine, mycophenolate mofetil, azathioprine, and cyclophosphamide may be used.

Some patients are not effectively treated by any available therapies due to lack of a stable response, or due to severe side effects of treatment.

4What are the FDA-approved drugs for treating AIHA?
Currently, there are no FDA-approved treatments for AIHA.
5What is a “Syk inhibitor"?
“Syk” stands for spleen tyrosine kinase, which is an enzyme that plays a very important role in cell signaling related to immune functions in the body. Abnormalities in this cell signaling can contribute to some autoimmune disorders, such as AIHA.
6For a list of referenced literature that supported this FAQ section, click here:
  1. https://www.researchgate.net/publication/26732505_Therapeutic_prospect_of_Syk_inhibitors
  2. Klein NP, Ray P, Carpenter D, et al. Rates of autoimmune diseases in Kaiser Permanente for use in vaccine adverse event safety studies. Vaccine. 2010;28(4):1062-1068.
  3. Eaton WW, Rose NR, Kalaydjian A, Pedersen MG, Mortensen PB. Epidemiology of autoimmune diseases in Denmark. J Autoimmun. 2007;29(1):1-9.
  4. Lichtin, A.E., Autoimmune Hemolytic Anemia. Merck Manual (2013). Retrieved from: http://www.merckmanuals.com/professional/hematology-and-oncology/anemias-caused-by-hemolysis/autoimmune-hemolytic-anemia
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4119858/
  6. National Organization for Rare Disorders, Rare Disease Information for Patients and Families. Retrieved from: https://rarediseases.org/rare-diseases/anemia-hemolytic-acquired-autoimmune/ and https://rarediseases.org/rare-diseases/evans-syndrome/
  7. Lechner K, Jäger U. How I treat autoimmune hemolytic anemias in adults. Blood. 2010;16:1831-8.
  8. Zanella A, Barcellini W. Treatment of autoimmune hemolytic anemia. Haematologica 2014;99(10):1547-1554

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