Hemolytic Transfusion Reaction

A hemolytic transfusion reaction (HTR) happens when your immune system destroys red blood cells that you receive in a blood transfusion. Your immune system attacks the donor blood cells because that blood doesn’t match your blood type. HTR can be a serious complication of a blood transfusion.

These reactions are very rare. Tests to check for potential issues and other guidelines reduce the risk of having a hemolytic transfusion reaction. And healthcare providers carefully watch for changes during the transfusion process that could be reaction symptoms. They do this so they can move quickly to manage the issue.

Condition types

A transfusion reaction may be acute, meaning it happens during or right after you receive blood. Some people have reactions several days or weeks after receiving blood. Healthcare providers call this a delayed hemolytic transfusion reaction.

Healthcare providers also classify the condition by the cause and how it affects your body:

• Immune-mediated reaction: This is when your immune system orders up attacks on donated red blood cells because the donor blood type and your blood type don’t match. The delayed form often happens when someone who has Rh factors in their blood receives blood from someone who doesn’t have the factor.
• Non-immune mediated reaction: In this case, your immune system may attack because it detects bacteria or viruses in the donor blood. This may also happen if you receive donor blood that wasn’t properly stored.
• Intravascular transfusion reaction: This is when your immune system attacks donor red blood cells in your blood vessels. This may happen if you have an acute hemolytic transfusion reaction.
• Extravascular transfusion reaction: In this case, donor red blood cells end up in your liver and spleen. There, special immune cells in your tissues destroy the donor cells. This typically happens if you have a delayed form of the condition.

Symptoms of hemolytic transfusion reaction

Acute and delayed forms of this condition cause different symptoms. The acute form causes symptoms, like:

• Chills and fever
• Confusion
• Dizziness and feeling lightheaded
• Nausea
• Pain in your chest, back or side

Delayed form symptoms are similar and may be less severe. You may also feel very tired, or your skin and the whites of your eyes may be yellow. This happens if a delayed hemolytic transfusion reaction causes jaundice.

Hemolytic transfusion reaction causes

The acute form of this condition happens when you receive donor blood that doesn’t match your blood type. It may also happen if you receive blood that contains bacteria or viruses. You may have the delayed form if you already have antibodies for specific blood types. That can happen if you have frequent blood transfusions or you’ve recently gone through pregnancy.

Complications of this condition

Acute hemolytic transfusion reactions can damage your kidneys or lead to disseminated intravascular coagulation (DIC). DIC is a rare blood-clotting disorder where your body makes more blood clots than you need. The delayed form of the condition may cause complications for people with sickle cell disease. Complications can include:

• Vaso-occlusive crisis: This is pain that happens when sickled cells block capillaries.
• Autoantibody production: Autoantibodies are malfunctioning antibodies. They harm your body instead of protecting it from intruders.
• Hyperhemolytic crisis: This is when your hemoglobin levels drop very quickly. Hemoglobin is a protein in your red blood cells. It helps the cells carry oxygen throughout your body.

How doctors diagnose HTR

Your healthcare team will be at your side during a blood transfusion. Don’t hesitate to tell a provider if something feels “off.” They’ll check your vital signs for changes like low blood pressure or fever. They’ll stop the transfusion and ask about your symptoms. They may do tests like:

• Coombs test to look for antibodies that attack red blood cells
• Urinalysis to check for blood in your pee
• LDH test to look for tissue damage
• Bilirubin test to check your liver
• Haptoglobin levels to look for signs of damaged red blood cells

How is this condition treated?

The first step is to stop the transfusion. Treatment for an acute hemolytic transfusion reaction may include:

• Acetaminophen for fever and pain
• Vasopressors to manage low blood pressure
• Diuretics to help you pee, which removes excess fluid
• Potassium binders to manage potassium levels
• Blood thinners to reduce the risk of blood clots that DIC may cause

Providers may do the following treatments for delayed hemolytic transfusion reaction:

• Supportive care, like acetaminophen for pain and fluids
• Erythropoietin to help your bone marrow make red blood cells
• Corticosteroids and intravenous immunoglobulin to slow your immune system’s reaction

When should I seek care?

HTR symptoms can happen right away or develop days or weeks after you have a blood transfusion. Tell your provider right away if you start to feel sick during a blood transfusion. Likewise, let them know if you feel very tired days or weeks after a blood transfusion. Fatigue may be a symptom of delayed hemolytic transfusion reaction.

What can I expect if I have this condition?

That depends on your situation. In general, people with mild symptoms recover with supportive care. But the condition can cause serious complications like acute kidney injury, DIC or severe anemia. Anyone who experiences this condition should plan to have additional pre-transfusion screening tests.