What Is Pure Red Cell Aplasia (PRCA)?

Pure red cell aplasia (PRCA) is a medical condition in which some of your red blood cells, the cells responsible for carrying oxygen around your body, don’t form normally. This can lead to one kind of anemia, causing symptoms like fatigue. 

The “pure” in red cell aplasia just means that other types of blood cells (like white blood cells) aren’t affected. “Aplasia” is a term that means lack of development.

Pure red cell aplasia is sometimes present from birth. Other times, it is caused by other medical conditions or medications.

This article will discuss some of the symptoms and causes of pure red cell aplasia, as well as its diagnosis and treatment. 

Symptoms of PRCA

Some people with pure red cell aplasia don’t notice any symptoms at all. But some potential symptoms include:

• Fatigue
• Dizziness
• Headache
• Feeling cold
• Shortness of breath
• Pale skin
• Difficulty sucking and gaining weight (for an infant)

If your condition is more severe and a higher percentage of your red blood cells are affected, you may be more likely to have symptoms. You may also be more likely to have symptoms if the underlying problem comes on suddenly.

Sometimes people with pure red cell aplasia also have additional symptoms because of the underlying condition that is causing it. 

Causes and Types of PRCA

All types of pure red cell aplasia occur when a person’s red blood cells don’t develop normally. This can happen due to different underlying issues. 

This leads to anemia—a problem when someone doesn’t have enough properly functioning red blood cells. That causes problems because these cells are important for transporting oxygen around your body.

Congenital Pure Red Cell Aplasia

Congenital PRCA is a type that a person has from birth, even though they might not show symptoms immediately. This type is caused by certain very rare genetic mutations inherited from one's parents. Because of these mutations, the body can’t make red blood cells normally. 

Congenital pure red cell aplasia also goes by the name “Diamond-Blackfan anemia.” People with this disorder often have other problems, such as malformations in certain organs, like the heart.

Acquired Pure Red Cell Aplasia 

In contrast, acquired PRCA is not something you have when you are born. Instead, it can result from several different medical conditions. Acquired pure red cell aplasia can be further separated into primary PRCA and secondary PRCA.

Primary Acquired PRCA

This type of PRCA is also sometimes called "idiopathic" PRCA, meaning doctors and researchers don't know exactly what causes it.

However, we now think primary acquired PRCA is some kind of autoimmune disorder. That’s a kind of disease in which part of your immune system gets inappropriately activated against some component of your own body. 

So, in primary acquired PRCA, the body may start to form antibodies against a protein found in immature red blood cells. That can damage those cells and make them unable to eventually perform their normal function. 

Secondary Acquired PRCA

Secondary acquired PRCA happens because of other underlying medical issues. For example, it can be triggered by different autoimmune disorders, such as the following:

• Rheumatoid arthritis
• Lupus 
• Inflammatory bowel disease

Some kinds of infections can also trigger this issue. Some of these are:

• Parvo B19 virus
• Viral hepatitis
• Mononucleosis
• Some bacterial infections, such as tuberculosis

Some kinds of cancers and malignancies can also trigger secondary acquired PRCA. Some examples are:

• Thymoma (a tumor of the thymus gland; most common cancerous cause)
• Lymphomas
• Leukemias
• Multiple myeloma

Some medications also seem to trigger the issue in a very small group of people who use them. Pregnancy is another rare cause of secondary acquired PRCA, but this resolves with delivery. 

Diagnosis

Diagnosis for PRCA is in two parts. First PRCA itself is diagnosed. After that, it’s important to identify any underlying causes.

Your healthcare provider will take your medical history, asking you about things like your current symptoms and your past medical problems. These can give clues about the diagnosis.

Lab Tests

Lab tests are also essential for diagnosis. An important closely related group of tests called a complete blood count (CBC) can be very helpful. This is a basic test run in a lot of different medical situations, but it can show that anemia is present. It can also give clues about the type of anemia.

For example, in PRCA, the red blood cells are same size as normal--there just aren't as many of them. Healthcare providers call this "normocytic" anemia. PRCA is only one potential cause for normocytic anemia. In contrast, anemia caused by iron deficiency causes red blood cells to be smaller than normal.

Another closed related blood test, called the reticulocyte count, shows that your body is not producing enough new red blood cells (as it normally would do inside your bone marrow).

To definitely diagnose PRCA, you may also need a bone marrow biopsy. By taking a sample of your bone marrow, a pathologist (a medical doctor that examines blood and tissues to identify and study diseases) can see that you aren’t making new red blood cells there as you normally should.

Other tests might be needed in specific circumstances, partly depending on the suspected cause. For example, you might need a blood test to check for infection with the B19 parvovirus. Or, if your healthcare provider is worried about a thymoma, you might need a computerized tomography (CT) scan of your chest.

Treatment

The main treatment approach for most people who have PRCA is immunosuppression. That just means that you’ll take medication to tone down your immune system’s abnormal attack on developing red blood cells.

Some treatments in this category include:

• Corticosteroids
• Neoral (cyclosporine; one of the most effective agents for PRCA)
• Cytoxan (cyclophosphamide)
• Azapres (azathioprine)
• Purixan (6-mercaptopurine)

People who had PRCA from certain specific causes may need some other therapies as well. Some examples are:

• Intravenous immunoglobulin for people with PRCA from the parvovirus
• Surgical removal of a thymoma, if present 
• Treatment for an underlying infection (e.g., with antibiotics)
• Removal of a drug possibly triggering PRCA
• Treatment for an underlying malignancy causing PRCA, like lymphoma

In severe cases, some people may need a blood transfusion, if the anemia is severe and doesn’t respond well to other interventions. This might be particularly likely for someone with congenital PRCA. 

People who need a lot of transfusions may also require chelation therapy. That’s needed to remove excess iron from the blood. (Having a lot of transfusions can put too much iron in the blood, which can be toxic.)

Special Considerations for Congenital PRCA

Children who have congenital PRCA may also need additional therapies, such as human growth hormone. This is because using corticosteroids over long periods of time can stunt their growth. During this therapy, they receive healthy stem cells from a donor. This would allow them to make healthy blood cells of their own in the future. This treatment, if successful, can completely cure the disease. 

Summary

Pure red cell aplasia (PRCA) is a medical condition in which your body doesn’t produce as many new red blood cells as it should. This leads to a kind of anemia. It can happen from many different causes, including congenital problems, infections, autoimmune disease, and cancer.

Its primary treatment is drugs that tamp down your immune system, like corticosteroids. Some people also need treatment for the underlying condition that is causing it.

A Word From Verywell

It is frustrating and scary to learn that you or your child has a condition like PRCA. Sometimes, you’ll have to be thinking about treating other underlying problems as well. But fortunately, most people are able to successfully manage their PRCA. Work closely with your medical team to get all your questions answered.