Warm autoimmune hemolytic anemia, or wAIHA (pronounced “way-ha”), is a rare, potentially life-threatening disease. It occurs when the body’s immune system produces autoantibodies—pathogenic antibodies—that attack and destroy healthy red blood cells.
Red blood cells have the vital job of delivering oxygen throughout the body, and antibodies normally protect the body from harmful invaders like bacteria and viruses. But when someone has wAIHA, immunoglobulin G (IgG) antibodies (the most common type of antibody) mistakenly mark red blood cells for destruction. This process is called hemolysis.
“Those antibodies are leading to prematurely destroying the red blood cells, sometimes faster than the body can produce new red blood cells,” explains Ann Leon, PharmD, Global Medical Affairs Leader of Benign Hematology at Johnson & Johnson. “This leads to anemia, which hinders oxygen delivery to every organ in the body.”
Anemia, a condition marked by low levels of red blood cells, in turn causes a range of debilitating symptoms. The term “warm” means that the antibodies bind to and attack red blood cells at normal body temperatures, as opposed to the mechanism behind other types of autoimmune hemolytic anemia, says Leon.
About one in 8,000 people live with wAIHA, but there are no drugs for the disease approved by the U.S. Food and Drug Administration (FDA) or the European Medicines Agency (EMA).
Here’s what to know about wAIHA, including Johnson & Johnson’s commitment to researching potential treatment options for patients with this disease.
The two types of wAIHA
Primary wAIHA—which accounts for about 60% of cases—doesn’t have an identifiable cause.
Experts classify wAIHA as secondary when it is caused by an underlying condition, such as a blood cancer, infection or another autoimmune disease. It can also be associated with some medications.
Either type of wAIHA can strike anyone at any age. However, the incidence of the disease becomes more common after age 50, and slightly more women than men develop wAIHA.
What are the symptoms of wAIHA?
Without enough red blood cells bringing oxygen to the body, anemia will develop and leave a person feeling depleted of energy. As a result, profound fatigue is the most common symptom of wAIHA.
“When anemia is severe, patients describe it as being unable to get out of bed,” says Leon. “If they can get up and take a shower, that can be all they do—they’re done for the day.” They may feel weak all over, too tired to cook a meal to eat and unable to start or finish tasks. They may be forced to limit social interactions and need extra sleep during daytime hours.
Along with fatigue, signs and symptoms can include dizziness, shortness of breath (especially with exertion), increased heart rate, yellowing of the skin and eyes, pale skin, chest pain and dark urine.
For many patients, wAIHA is recurrent; they experience periods of remission and then relapses in which symptoms return. About two-thirds of patients have some type of relapse, says Leon. On top of dealing with symptom recurrences, relapses can take an emotional toll, leading to anxiety and depression.
“Patients may suffer from significant physical effects as well as emotional effects,” she explains. “They have the burden of wondering if and when the condition will worsen and how severely or suddenly, usually with little warning.”
How wAIHA is diagnosed
The first step toward a diagnosis is having a healthcare provider check a person’s complete blood count, which measures red and white blood cell levels. A blood count will also show whether hemoglobin is low, which is a hallmark sign of anemia.
If anemia is discovered, clinicians will look into all possible causes, such as iron deficiency, says Leon. Tests can distinguish hemolysis and then more blood tests will be ordered. “Specifically, the Direct Antiglobulin Test can uncover if IgG antibodies are attacking red blood cells and thus confirm wAIHA,” she says.
Physicians then do further testing to determine the presence of an associated condition, like lupus or blood cancer, which could be the underlying cause of wAIHA. This helps patients get the appropriate treatment for those diseases, and that often improves symptoms, says Leon. If wAIHA remains undiagnosed, anemia can become severe, compromising blood oxygenation in organs and tissues.
Treatment for wAIHA
wAIHA is classified as a rare disease, which means it affects so few people that it’s difficult to find enough study subjects to conduct clinical trials on the effectiveness of potential treatments. “Because studies are challenging to conduct, clinicians have few studies upon which to base treatment decisions,” says Leon.
In the absence of an FDA- or EMA-approved therapy for wAIHA, healthcare providers typically try solutions that help manage symptoms by increasing hemoglobin levels and decreasing hemolysis. One first-line treatment is high-dose corticosteroids, a type of anti-inflammatory medication.
B-cell depletion therapy is another option. B cells are white blood cells that can create antibodies that attack red blood cells.
Some patients with wAIHA may have their spleen removed, as the spleen is where antibodies destroy red blood cells. Other treatments include taking immunosuppressant drugs or receiving blood transfusions. But newer options that can provide sustained disease control, have a demonstrated safety profile and target the specific mechanisms of the disease are needed, says Leon.
Johnson & Johnson has been conducting clinical studies for a potential targeted treatment for wAIHA that is designed to potentially address the underlying cause of the disease without impacting other immune functions. “We’re looking forward to being able to share the clinical study data,” says Leon.
As part of its research into wAIHA, Johnson & Johnson has also partnered with patients and amplified their voices with the goal of understanding the personal impact of this disease. The company created a patient council to learn from people living with wAIHA about their diagnosis and treatment journeys, plus how the condition affects their day-to-day lives.
Autoimmune conditions, including those classified as rare diseases, have long been a focus for Johnson & Johnson, says Leon. That focus includes the 80-plus autoantibody-driven conditions severely impacting nearly 240 million people worldwide.
“We have an opportunity to potentially help address this unmet need for patients with wAIHA who don’t have an approved therapy indicated for their disease,” she says. It would be a profound step forward for the scientists and healthcare providers dedicated to studying autoimmune disorders—as well as for patients who live with them.
