Autoimmune hemolytic anemia (AIHA) is a condition in which the immune system destroys red blood cells (RBCs) in a process called hemolysis. This can cause problems like anemia (low RBC levels) and jaundice (yellowed skin or eyes).

AIHA can be managed, but up to 3 out of 10 people with the condition have severe anemia that requires more aggressive treatment, such as medication, a surgical procedure, or blood transfusions.

Blood Transfusions in AIHA

During a blood transfusion, you receive blood or parts of blood, such as certain types of blood cells, from a donor. If you have AIHA, you may need a transfusion of red blood cells if:

• You have low levels of hemoglobin (a protein inside red blood cells that carries oxygen).
• You have other health problems such as heart or lung disease.
• Your AIHA starts out more severe or quickly gets worse.

Blood transfusions don’t cure AIHA because they don’t address the underlying problem that causes red blood cell death. However, they can relieve AIHA symptoms by giving your body additional RBCs to replace the ones that are being destroyed.

How Effective Are Blood Transfusions?

Red blood cell transfusions can be very helpful for some people, but they don’t always work as well as doctors hope.

In one recent study published in the journal Medicine, researchers reported that blood transfusions were about 56 percent effective. This means that more than half of the time, this treatment improved symptoms, treated complications, and boosted health.

However, for some people with severe AIHA, blood transfusions may not work and symptoms may persist. In this case, doctors may try other AIHA treatments, such as steroid drugs like prednisone and danazol, IV immunoglobulins (a treatment in which helpful antibodies are given intravenously), or plasmapheresis (a procedure that removes harmful antibodies from the blood).

Finding Compatible Donor Blood

Before a blood transfusion, your doctor will try to find red blood cells that “match” your own. This process is called cross-matching. Essentially, donor blood is mixed in a test tube with the blood of the person with AIHA. If the donor blood is not compatible, hemolysis will happen in the test tube.

All RBCs contain different types of proteins called antigens that can react with your immune system. Undergoing compatibility testing and receiving matched blood can help reduce the risk of your immune system fighting the transfused RBCs.

ABO Blood Typing

First, the donor blood will be analyzed to make sure it is compatible with your blood type. For example, people with type AB blood can generally receive type A, B, AB, or O blood, while those with type O need donor blood that is also type O.

Alloantibodies

Transfusions can result in harmful reactions if you receive donor blood that is not compatible with your immune system. Your body may make alloantibodies — immune system proteins that attack red blood cells that come from other people. These are different from autoantibodies, which attack your own RBCs.

Studies estimate that between 15 percent and 40 percent of people with AIHA have alloantibodies, which may make it harder to find matching donor blood and could delay treatment. Alloantibodies can lead to side effects after a transfusion with incompatible blood. One possible side effect is a hemolytic transfusion reaction, in which your body destroys the new donor RBCs.

To minimize risk, doctors often try to find compatible donor blood. However, it is difficult, expensive, and time-consuming to detect alloantibodies, and not all health care facilities are able to perform this testing. In some cases, including in emergency situations, doctors may administer donor blood that has the potential to cause reactions. Experts increasingly believe that it is OK if the donor blood isn’t a perfect match — that these transfusions can be just as effective for treating AIHA, and those with the condition could face very serious health problems if blood transfusions are delayed in the attempt to find the best match.

Treating Blood Transfusion Reactions

Although RBC transfusions can be very helpful, they sometimes cause adverse reactions (side effects). However, these are usually rare — the authors of the study in Medicine estimated that among 885 blood transfusion treatments for AIHA, only 1.6 percent caused additional health problems, indicating that this treatment is usually safe.

Several types of adverse reactions may occur after a blood transfusion, but treatments can usually help improve health. If you start to feel different during or after a blood transfusion for AIHA, tell your doctor right away so that the transfusion can be stopped and any reactions can be treated immediately.

Fever

In the study discussed above, most of the transfusion reactions involved fever, which may occur along with chills.

A fever after a blood transfusion is usually minor and often goes away on its own or with medication. However, in some cases, a fever can be a sign of a serious health problem. This may include transfusion-related acute lung injury — a type of lung damage — as well as a life-threatening condition called septic transfusion reaction.

Your doctor will likely monitor your body temperature during a transfusion and should stop treatment if your temperature starts to rise. Chest pain or nausea can also indicate a severe reaction, so tell your doctor if you notice these symptoms along with a fever.

Allergic Reaction

Occasionally, a person undergoing a blood transfusion for AIHA might experience an allergic reaction to the donor blood. Mild allergic reactions can be treated with antihistamines (allergy medications). However, some reactions may be severe or life-threatening and require immediate treatment.

Hives or itchiness can be signs of an allergic reaction. Tell your doctor right away if you think you may be experiencing this side effect.

Hypothermia

Hypothermia is a condition in which your body temperature drops too low. This can happen during a blood transfusion if you receive a lot of blood cells that are cold because of refrigeration.

Hypothermia can be serious if not addressed, but doctors can treat it by warming you with blankets or heaters and making sure that the donor blood is warmed before it is delivered into your veins.

Other Side Effects

Following blood transfusion therapy, some people experience symptoms such as a headache or increased blood pressure. These side effects are generally not serious.

Signs of a more severe reaction include:

• Shortness of breath
• Blood in urine
• Low blood pressure, which may lead to dizziness, lightheadedness, or fainting

These symptoms are rare, but you should seek emergency medical care if you notice them.

Preventing Reactions to Blood Transfusions

To try to prevent side effects, doctors sometimes give medications before a blood transfusion. These drugs include dexamethasone (Decadron) and promethazine (Phenergan). However, there’s not a lot of evidence that these medications work — studies have found that people experience transfusion side effects at similar rates whether or not they receive these drugs.

Talk With Others Who Understand

At myAIHAteam, people with AIHA and their loved ones come together to ask questions, give advice, and share their stories with others who understand life with this condition.

Have you needed blood transfusions while living with AIHA? Did you have any side effects? Share your experience in the comments below, or start a conversation by posting on myAIHAteam.