Chronic lymphocytic leukemia (CLL) is a cancer of the blood and bone marrow. CLL begins in cells that mature into lymphocytes, a type of white blood cell.

In CLL, the bone marrow overproduces abnormal lymphocytes that do not function as they should. Over time, these abnormal lymphocytes accumulate in the bone marrow and begin crowding out other healthy blood cells.

This process can reduce the number of red blood cells, which may trigger CLL-related anemia.

This article describes CLL and outlines the link between CLL and anemia. It also describes the symptoms of anemia and provides information on diagnosing, treating, and preventing CLL-related anemia.

CLL is a type of cancer that affects cells that mature into lymphocytes. There are two main types of lymphocytes: B-lymphocytes that produce antibodies and T-lymphocytes that help kill tumor cells and regulate the immune response.

In CLL, the bone marrow overproduces lymphocytes that do not function as they should. Over time, these abnormal lymphocytes crowd out healthy lymphocytes and other types of blood cells. This can lead to various health complications and associated symptoms.

CLL is a disease that progresses slowly. Many people do not need immediate treatment and can be symptom-free for years before they require treatment.

Prevalence

CLL is the most common form of leukemia in adults. It typically occurs in older people and is rare in people below age 40 years. It is also rare in children.

Additionally, CLL is twice as common in males than females.

The American Cancer Society (ACS) estimates that there will be around 20,700 new cases of CLL in the United States in 2024.

Anemia is a condition of reduced red blood cells (RBCs) or low hemoglobin within these cells. Hemoglobin is a protein that delivers oxygen to the body’s organs and tissues and transports carbon dioxide away from these areas and back to the lungs.

Most people who develop anemia have deficiencies in iron or folate, both of which are essential for the production of healthy RBCs.

Symptoms of anemia

People with anemia may experience one or more of the following symptoms:

When a person has advanced-stage CLL, the unhealthy lymphocytes outnumber the healthy lymphocytes and other blood cells. A person will develop anemia if the number of RBCs falls too low.

The side effects of CLL treatment can also lead to anemia. Side effects such as nausea, vomiting, and decreased appetite may make it difficult for a person to consume a well-balanced, iron-rich diet.

This can lead to iron deficiency anemia, in which the iron level in the blood is too low to support the production of new RBCs.

Some treatments, such as chemotherapy agents, can also result in anemia due to bone marrow suppression.

CLL affects the immune system in various ways. In about 25% of people with CLL, the immune system cells attack normal RBCs, mistaking them for foreign invaders. This causes a condition called autoimmune hemolytic anemia (AHA).

The condition can be chronic or life threatening. Further blood tests are essential to identify the cause of the anemia, as doctors treat AHA differently from other conditions.

CLL results from gene mutations within the DNA of blood-producing cells. These mutations trigger the body to produce abnormal lymphocytes, which are ineffective at fighting infection. They also interfere with the balance of other types of blood cells, including RBCs. A reduction in RBCs may trigger CLL-related anemia.

Studies suggest that the impact of CLL-related anemia on a person’s quality of life depends on the severity of the anemia. Factors that play a role in the severity of CLL-related anemia include:

  • the duration of the CLL
  • the type and intensity of chemotherapy treatment
  • the frequency and severity of infections

People with CLL require regular health checks so their medical team can record new symptoms and run additional diagnostic tests if necessary.

If a doctor suspects someone has anemia, they will perform a physical examination and request a complete blood count (CBC). This blood test assesses the relative numbers of RBCs and other types of blood cells in the sample.

If the doctor suspects AHA, they may request a Coombs test, or direct antiglobulin test (DAT). This test involves isolating the RBCs from a blood sample and incubating them with a substance called Coombs reagent. If the blood cells clump together, this indicates a person has AHA.

People with anemia symptoms should avoid self-diagnosis and consult their doctor for an accurate medical assessment.

The treatment for CLL-related anemia depends on the ongoing cancer treatment regimen for CLL and the symptoms and severity of the anemia. Doctors will decide the best course of action on a case-by-case basis.

Potential treatment options for CLL-related anemia include blood transfusions and drugs called erythropoiesis-stimulating agents (ESAs). If anemia is due to deficiencies in iron, folate, or vitamin B12, doctors may recommend treatment with supplements.

Blood transfusions

Some people require blood transfusions to boost their levels of RBCs. However, such transfusions can potentially transmit infections and cause iron overload in the body.

A person may also experience alloimmunization, which is a potentially fatal complication of regular blood transfusions. It occurs due to an immune response to antigens in the donated blood, which can result in a hemolytic reaction.

Erythropoiesis-stimulating agents (ESAs)

ESAs stimulate the bone marrow to produce more RBCs.

According to an older review article, doctors recommend ESAs for people with CLL and hemoglobin levels of less than 10 grams per deciliter (g/dl).

ESAs are more effective than blood transfusions in treating CLL-related anemia because they help maintain consistent hemoglobin levels.

Anemia is a common occurrence in people with cancer. Due to the nature of CLL and its treatment, it can be difficult to prevent anemia.

However, most people with CLL-related anemia can usually manage the condition if a doctor diagnoses and treats it in its early stages. This is why people with CLL and other types of leukemia require regular checkups.

CLL occurs when the bone marrow overproduces abnormal lymphocytes. Over time, these abnormal lymphocytes accumulate and begin to crowd out healthy blood cells. This can lead to a reduction in the number of RBCs, which may trigger anemia.

With early diagnosis and treatment, it is possible to manage CLL-related anemia.

Treatment options include blood transfusions and ESAs. A doctor will evaluate a suitable treatment plan based on the person’s age, medical history, and other ongoing cancer therapies.

Leukemia resources

Visit our dedicated hub for more research-backed information and in-depth resources on leukemia.