What is wAIHA?Learn more about this rare disease.

What is wAIHA?

Warm Autoimmune Hemolytic Anemia (wAIHA) is a clinical form of AIHA, in which the immune system creates antibodies (typically IgG) that destroy healthy red blood cells. wAIHA is unique with antibodies operating at its greatest point at body temperature 36.5–37.5 °C (97.7–99.5 °F).

wAIHA can be classified as idiopathic (primary) or secondary, determining the approach of treatment. Treatment options are inclusive primarily of corticosteroids and then a splenectomy or immunosuppressors if needed.

How does wAIHA work in the body?

The components shown here can create the conditions for wAIHA in a patient. Scroll on to see how this works!

Red blood cell

Macrophage

Antibody

Antigen

Complement deposit

Spherocyte

Red Blood Cells are the primary way of delivering oxygen to a body's tissues. These are examples of healthy blood RBC.

RBC antigens are molecules that start an immune response by antibodies.

Warm IgG (wIgG) antibodies are the Y-shaped figures here. They're proteins that mistakenly attach to the antigens.

As the the wIgG antibodies attach to the antigens, complement deposits - the square shapes shown here - form on the bound up red blood cell.

From here, two processes can begin in a person's body.

Extravascular Hemolysis

Intravascular Hemolysis

Extravascular Hemolysis is when macrophages in the liver or the spleen eats up and gets rid of the IgG red blood cells.

Intravascular Hemolysis is when the pores on the red blood cell allows for the contents to leak out of the cell.

Macrophage is a kind of white blood cell. The macrophage kills foreign substances through a process called phagocytosis.

Hemoglobin output from red blood cell destruction leads to jaundice (yellowing of skin), dark urine, enlarged spleen or liver.

Spherocytes are partially phagocytosed RBC that has more of a spherical shape. It has a shorter half-life that goes back into circulation.

Spherocytes are partially phagocytosed RBC that has more of a spherical shape. It has a shorter half-life that goes back into circulation.

Extravascular Hemolysis

Macrophages in spleen or liver envelop and eliminate (phagocytose) the IgG/IgG complement RBC.

Spherocytes, more rigid, spherical shaped, partially-phagocytosed RBCs go back to being circulated with a short half-life.

At first, a person has these healthy red blood cells.

RBC antigens, or molecules that start immune response by antibodies.

Warm IgG autoantibodies - the blue Y's - mistakenly attach to the antigens.

Complement deposits - the blue squares - form on these RBCs

Intravascular hemolysis

Formed pores on RBC allow for the content to leak out.

What are the symptoms of wAIHA?

Symptoms generally develop from a timeframe of several weeks to several months (who may be asymptomatic initially), though they may occasionally develop over a few days. Symptoms vary from person-to-person, dependent on onset rate, healthy red blood count destruction rate, and if there is an  underlying disorder.

COMMON SYMPTOMSAbnormal paleness of the skin (pallor)
Dizziness
Muscle weakness
Fatigue
Palpitations
Shortness of breath when exercising (Exertional dyspnea)
Mild splenomegaly

RARER SYMPTOMS
Dark urine (hemolysis)
Yellowing of the skin and whites of the eyes (Jaundice)

SYMPTOMS OF SEVERE wAIHA
Symptoms indicating severe wAIHA, particularly for quick onset, include:
Loss of consciousness (syncope)
Chest pain (angina)
Abnormally rapid heartbeats (tachycardia)
Heart failure

Peak Age

50-70 years old

People of any age can have wAIHA with the peak age being 50-70 years old

Biology

No familial hereditary component

Women have the same likelihood as men to have wAIHA

Prevalence

17/
100,000

Every 17 individuals out of 100,000 have wAIHA

Incidence

1-3/
100,000

Every 1 to 3 individuals out of 100,000 have wAIHA every year

Women : Men

1:1

Women have the same likelihood as men to have wAIHA

wAIHA Symptoms

Symptoms generally develop from a timeframe of several weeks to several months (who may be asymptomatic initially), though may occasionally develop over a few days. These symptoms vary from person-to-person, dependent on onset rate, healthy red blood count destruction rate, and if there is an underlying disorder.

In those who have wAIHA, the immune system produces autoantibodies that destroy red blood cells rather than toxins like viruses, cancerous cells, and bacteria. Therefore, these red blood cells live only a few days and become metabolised quicker than they are produced. This imbalance of red blood cells input and output then creates the symptoms (pallor, shortness of breath, fatigue, dizziness,etc.) of wAIHA.

common symptoms

  • Abnormal paleness of the skin (pallor)
  • Dizziness
  • Fatigue
  • Palpitations
  • Shortness of breath when exercising (Exertional dyspnea)
  • Mild splenomegaly

Symptoms of Severe wAIHA

  • Loss of consciousness (syncope)
  • Abnormally rapid heartbeats (tachycardia)
  • Chest pain (angina)
  • Heart failure

Rarer Symptoms

  • Dark Urine (hemolysis)
  • Yellowing of the skin and whites of the eyes (Jaundice)

Treatment options

Our goal is to increase engagement and awareness of wAIHA with our patients, families, caregivers, and advocates. It is our hope more discoveries can contribute to improving the understanding and treatment of wAIHA. This feature allows you to navigate through the existing research programs and clinical trials.

Please contact us if you would like your research program or clinical trial to be published.

Current treatments

There are several treatment options for wAIHA. As the first line is administered, physicians will watch to see how their patients react to the medication. If no improvements are seen, they walk down the lines of therapy. Generally, these lines of therapy are as below:

First line
Corticosteroids and RBC transfusion

SECOND LINE
Immunosuppressive agents
Rituximab

THIRD LINE
Splenectomy

Clinical trials

Clinical trials are where the newest therapies are tested for their effectiveness and safety within a group of patients. While these treatments are not yet proven, the treatments being tested in clinical trial settings represent the cutting-edge of medicine, and are offered by some of the world's leading researchers, care teams, and institutions.

Currently, there are multiple studies testing new therapies for wAIHA. If you'd like to learn more, please visit our Clinical Trial Hub by clicking on the button below! 

Visit the hub

Treatment options

These are the most common treatments used in managing the symptoms of wAIHA.
If you'd like to learn more about any of these options, please contact our team!

Corticosteroids

Prednisone:
Typically a high dose that is incrementally decreased with time

Splenectomy

Laparoscopic or open surgery performed to remove the spleen to stop early red blood cell loss

Severe form of wAIHA with continuous use of prednisone needed

Immunosuppressive Drugs

Cyclophosphamide:
Have helped when corticosteroids or splenectomy has not worked

Rituximab

Low-dose artificial antibody (biologic) that kills white blood cells that create antibodies that kill red blood cells

This can be used with corticosteroids and is beneficial for when prednisone does not work.

This can also be used before or after splenectomy.

Red blood cell
transfusion

Increases red blood cell count, but doesn’t treat root-cause of disease; only a short-term benefit.

Red blood cell
transfusion

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Red blood cell
transfusion

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Splenectomy

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