Warm hemolytic anemia is a rare condition that affects your red blood cells. It causes anemia-like symptoms, such as fatigue, jaundice, and paleness.
In warm hemolytic anemia, the destruction of red blood cells happens at body temperature. This isn’t always the case with other types of hemolytic anemias.
The condition is very uncommon, affecting about 1 to 3 people per 100,000 per year. In some cases, doctors can’t identify the cause.
Without treatment, it may be life threatening, but early treatment can be highly effective and lead to remission.
Read on to learn more about warm hemolytic anemia.
Warm hemolytic anemia occurs when your body mistakes its red blood cells for a harmful substance. It produces antibodies that attack and prematurely destroy the cells, leading to anemia.
Red blood cells, responsible for delivering oxygen throughout the body, normally live about
Warm hemolytic anemia differs from other types of hemolytic anemia because the antibodies will react at body temperature. There are different temperature ranges for other forms of the condition.
The signs and symptoms can be subtle at first, and they often mimic those of general anemia.
Some symptoms to look out for include:
- fatigue
- paleness
- poor concentration
- headache
- shortness of breath
If the condition progresses, signs of more severe anemia include:
- jaundice, or yellowing of the skin and eyes
- dark urine
- elevated bilirubin and lactate dehydrogenase levels in the blood
People with a severe form of the condition have a higher risk of deep vein thrombosis and pulmonary embolism.
Warm hemolytic anemia results from antibodies that attack red blood cells at normal body temperatures.
In about half of all cases, there’s no definitive underlying cause for this. But in other instances, there may be a link to another autoimmune condition, such as:
Additionally, there are cases appearing in people who’ve had:
- chronic lymphocytic leukemia
- non-Hodgkin’s lymphoma
- recent organ transplants
- cancer treatments
Anyone at any age can develop the condition, but it’s more common in adults between the ages of 50 and 70 years. Its average age of onset is 52 years.
The only way to reach a diagnosis is through blood tests.
If your doctor suspects warm hemolytic anemia, the first test they order will be a complete blood count (CBC). This test will show any warning signs of anemia. It’ll look at red and white blood cells, platelet count, hemoglobin (a blood protein), and your hematocrit.
Your doctor will order
- Reticulocyte count: This is a count of how many young red blood cells are in your blood. If it’s high, it means your bone marrow is working hard to make up for the destroyed cells.
- Lactase dehydrogenase: This is an enzyme present in red blood cells. This level rises when the body destroys red blood cells.
- Bilirubin test: Bilirubin is produced by the liver, and its levels rise when red blood cells are destroyed.
- Haptoglobin test: This protein gets rid of damaged red blood cell waste. These levels will be low if you’re using up haptoglobin.
- DAT: Also called the Coombs test, this direct antiglobulin test can confirm if your body is making antibodies against your red blood cells.
- Eluate assessment: This lab test investigates the red blood cell membrane. Based on its reaction, it can confirm a diagnosis of warm autoimmune hemolytic anemia.
- Peripheral blood smear: This test examines your blood under a microscope to see if your body is destroying your blood cells.
Warm hemolytic anemia is the most common type of autoimmune hemolytic anemia.
Cold hemolytic anemia, also known as cold agglutinin disease, is more rare. In this condition, antibodies destroy red blood cells at colder temperatures, usually 37°F to 39°F (3°C to 4°C).
The symptoms of cold hemolytic anemia may be similar to those of warm hemolytic anemia, but they may also include:
- cold hands and feet
- chest pain
- Raynaud phenomenon
- cardiac arrhythmias
Cold hemolytic anemia will have different causes and treatment options than warm hemolytic anemia.
Sometimes, treating any underlying conditions can resolve the symptoms of warm hemolytic anemia. In very mild cases without an underlying condition, it might not need treatment.
In other instances, several treatment options can help manage the condition or bring about a remission:
- Corticosteroids: Corticosteroids are often a first-line treatment for the condition and can be effective in
85% of people, according to a 2022 paper. However, long-term use may have serious side effects, and fewer than one-third of people maintain a good response after stopping corticosteroid use. - Rituximab: Rituximab can treat some autoimmune conditions. The same paper estimates that it can lead to remission in over 75% of people with warm hemolytic anemia. Its effects may be long lasting, and it can be useful for those whose condition stops responding to corticosteroids.
- Immunosuppressants: Immunosuppressants can help if rituximab doesn’t work or is unavailable. According to the 2022 paper, these medications help over 50% of people whose condition doesn’t respond to rituximab.
- Splenectomy: Spleen removal is usually the last option, but it can offer long-term remission in over two-thirds of people. It’s a less popular option, however. This is because it carries a higher risk of infection.
- Newer medications: Emerging therapies — such as fostamatinib, rilzabrutinib, and FcRn inhibitors — are showing promise as a treatment, but they’re not yet widely available.
Mild cases of warm hemolytic anemia often have no symptoms. You should contact a doctor if you begin to notice signs of worsening anemia, such as:
- dark urine
- jaundice
- increased fatigue
- extreme paleness
- dizziness or confusion
Warm hemolytic anemia is a rare condition in which your body attacks its own red blood cells at body temperature. This rapid destruction of red blood cells can lead to symptoms such as increased fatigue, jaundice, paleness, and dark urine.
Sometimes, the condition is linked to an underlying autoimmune condition, but other times, it may develop without a known cause.
Treatment options usually start with corticosteroids, but other medications — such as rituximab and immunosuppressants — may help. With early diagnosis and treatment, an extended remission is possible.