Is CLL an Autoimmune Disease? How CLL Affects the Immune System

Chronic lymphocytic leukemia (CLL) is a type of blood cancer. It can affect the immune system in several ways. This article explains how CLL interacts with the immune system. It also explains why autoimmune diseases can happen to people with CLL. 

Is CLL an autoimmune disease?

CLL is not an autoimmune disease. It is a cancer that affects white blood cells. Autoimmune diseases happen when the immune system attacks healthy cells. For example, the immune system may target a person’s own blood cells or organs. 

CLL develops in a different way. It begins when B cells become cancer cells. These cells then grow out of control. However, CLL can still affect how the immune system behaves. These changes may trigger autoimmune reactions. 

How common are autoimmune diseases in CLL?

Autoimmune diseases are fairly common in people with CLL. Studies show that up to 25% of people with CLL develop them. Autoimmune hemolytic anemia is the most common. Other autoimmune conditions happen less often.  

The most common autoimmune diseases affect blood cells. These are called autoimmune cytopenias. This means the immune system destroys certain blood cells. They include:

• Autoimmune hemolytic anemia (AIHA). In this condition, the immune system targets red blood cells. Red blood cells carry oxygen through the body. When these cells are reduced, anemia can develop. People may feel tired, weak, or short of breath.
• Immune thrombocytopenia (ITP). Platelets help the blood clot. When platelets are lowered, bruising and bleeding may happen more easily.
• Pure red cell aplasia (PRCA). In this condition, the bone marrow stops making red blood cells. This also leads to anemia.
• Other autoimmune diseases. Most autoimmune conditions that are seen in people with CLL affect blood cells. However, other types may also happen. These include rheumatoid arthritis, lupus, psoriasis, and autoimmune thyroid issues. One study followed more than 900 people with CLL. About 10% developed autoimmune diseases outside the blood. 

For people with CLL, these conditions can appear anytime. They may happen even when patients are in remission. Sometimes autoimmune diseases appear before CLL is diagnosed. However, this does not happen often.  

Why autoimmune diseases affect people with CLL 

CLL can disrupt how the immune system works. Doctors call this immune dysregulation. This means the immune system becomes unbalanced. An unbalanced immune system cannot regulate itself normally. 

Several immune changes may cause this problem. Immune cells may send incorrect signals to each other. Changes may also affect T cells. T cells help control immune responses.

B cells may produce abnormal antibodies. Antibodies normally help the body fight infection. Inflammation may also increase in the immune system. These changes can confuse the immune system. It may attack healthy blood cells by mistake. 

Some of these reasons may be why CLL causes autoimmune hemolytic anemia (AIHA) and other autoimmune diseases. AIHA is the most common type of autoimmune condition that affects people with CLL. 

How doctors treat autoimmune diseases for people with CLL 

Treatment depends on the type of autoimmune condition and how severe it is. Doctors may use treatments like steroids to reduce immune system activity. Sometimes doctors treat the leukemia itself. Treating CLL may improve autoimmune symptoms. Discover CLL treatments here. 

Recognizing symptoms early can also help. Early treatment may prevent autoimmune diseases from getting worse. 

Researching the link between CLL and autoimmune conditions 

Scientists are continuing to study how CLL and autoimmune diseases are connected. Some of this research includes looking at biomarkers in blood and cells. Biomarkers are signs that may predict autoimmune issues. 

Researchers are also studying immune checkpoint pathways. These pathways help control immune responses in the body. This research may help doctors predict autoimmune diseases earlier. It may also help prevent or better manage these conditions for people with CLL. 

Key takeaways

CLL is not an autoimmune disease. However, CLL can disrupt the immune system. These changes may cause autoimmune conditions in people with CLL. Work with your doctor to help you get the treatment you need. Researchers continue to study CLL and autoimmune diseases. This research may help doctors find these problems earlier. It may also help prevent and better manage these conditions. 

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Sources: 

• Autoimmunity promotes chronic lymphocytic leukemia progression in an indolent disease model
• Recognizing Signs of Autoimmune Disease in Patients With Chronic Lymphocytic Leukemia
• Is CLL an Autoimmune Disease?
• Strategies for Managing Autoimmune Complications in CLL
• Autoimmune Complications in Chronic Lymphocytic Leukemia in the Era of Targeted Drugs
• Immune system genes linked to most common type of leukaemia
• Chronic lymphocytic leukemia and autoimmunity: a systematic review
• Patients with Chronic Lymphocytic and Non-Hematologic Autoimmune Disorders Show Distinctive Clinical and Immune Alterations in Th17 and Treg Cells