B-cell acute lymphoblastic leukemia is a type of acute lymphoblastic leukemia (ALL). It is cancer that affects white blood cells known as B-cell lymphoblasts.

Lymphocytes form part of the immune system and protect the body against infections. People who have B-cell acute lymphoblastic leukemia have too many immature B-cell lymphoblasts in their bloodstream and bone marrow that do not work correctly.

As these leukemia cells increase, there are fewer healthy, mature white blood cells that fight infections and disease, red blood cells, and platelets. People with B-cell acute lymphoblastic leukemia may experience infections and anemia. They may also bleed easily.

B-cell lymphoblastic leukemia is the most common type of acute lymphoblastic leukemias or lymphomas, making up around 75% of adult leukemia cases. It can affect both adults and children.

This article looks at B cell acute lymphoblastic leukemia, as well as its causes, symptoms, and prognosis. It also explores how doctors diagnose and treat the condition.

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ALL accounts for less than 0.5% of all cancers in the United States and 80% of these cases occur in children.

Doctors do not understand the exact cause of B-cell acute lymphoblastic leukemia. They do know that it involves the DNA in the bone marrow that controls how white blood cells divide, grow, and die.

In B-cell acute lymphoblastic leukemia, mutations or changes in the DNA mean that the cells do not follow the normal process of growth and maturation. Instead, the cells replicate and divide more rapidly and release immature white blood cells. These are called leukemia cells.

Mature B-cells mark infected cells with a protein, which other immune system cells then destroy. Leukemia cells are not capable of protecting the body from infection.

Scientists remain unsure why this happens but think it may be a combination of genetic and environmental factors.

Genetic changes can make someone more likely to develop leukemia by increasing the likelihood that mutations occur within their bone marrow.

For example, in adults, a change can happen if the DNA from a chromosome breaks off and attaches to a different chromosome. This is called translocation. In adults with ALL, the most common translocation is between chromosomes 9 and 22, and results in what is called the Philadelphia chromosome.

People with chromosomal conditions like Down syndrome also have an increased risk of developing B-cell acute lymphoblastic leukemia.

Usually, people develop the DNA mutations that can lead to ALL, rather than inheriting them. They may happen because the person had exposure to radiation or cancer-causing chemicals, but often the cause is unclear. Mutations can also occur because people have undergone radiotherapy and chemotherapy for other cancer.

Certain other factors can increase a person’s risk of developing B-cell acute lymphoblastic leukemia, including high birth weight and smoking.

Many ALL symptoms are due to shortages of normal mature blood cells and can include:

  • weight loss
  • fever
  • reduced appetite
  • night sweats
  • pale skin
  • fatigue
  • bruising
  • shortness of breath
  • dizziness
  • infections
  • bleeding gums or nosebleeds
  • enlarged lymph nodes

People may also have a swollen abdomen due to a build-up of leukemia cells in the liver and spleen. If the leukemia cells build up near the surface of the bone or inside joints, this can cause pain.

Doctors diagnose ALL by using various tests to inspect the bone marrow or blood for signs of abnormal cells and to identify specific cells. Understanding someone’s diagnosis helps the doctor estimate how ALL may progress and determine the best treatment for them.

Tests may include:

  • Complete blood count (CBC): To measure red and white blood cells, platelets, and hemoglobin.
  • Bone marrow aspiration and biopsy: To remove cells for examination.
  • Cell assessments: To see if the cells are normal and mature blood cells or abnormal, immature blood cells.
  • Immunophenotyping: To look for specialized proteins on leukemia cells.
  • Genetic tests: To measure chromosomes and genes.

Doctors confirm a diagnosis of ALL if 20% of the bone marrow cells are lymphoblasts.

There are no proven methods to prevent someone from developing leukemia. In general, people should avoid unnecessary exposure to cancer-causing chemicals like benzene, pesticides, and radiation as much as possible.

People should also avoid smoking and smoke inhalation, a risk factor for many cancers, including leukemias like ALL.

For adults with ALL, doctors usually use long-term chemotherapy. More intensive regimens may result in better responses but can cause more side effects, like low white blood cell counts.

Treatment usually has induction, consolidation, and maintenance phases that span around 2 years, although the ALL subtype and other factors can affect the length and intensity of the regime.

The first phase of treatment is induction therapy, which uses medication to help stabilize and reduce the number of lymphoblasts and regulate the individual’s blood cell production. After this phase, for most people, the leukemia is in remission, meaning that there are no leukemia cells in bone marrow samples, and the person has normal blood counts.

The other stages of treatment aim to destroy any remaining leukemia cells in the body. The stages vary in length and intensity depending on how the leukemia responds.

Stem cell transplants are an option for some individuals to replace bone marrow affected by lymphoblasts with healthier, new bone marrow. Doctors need to match the donor bone marrow carefully to the individual.

Children with ALL receive a similar three-phase chemotherapy regime but may also need prolonged hospital stays for treatment, as infections and other complications can occur.

Children also receive chemotherapy in the cerebrospinal fluid (CSF) to kill any cancer cells in the brain and spinal cord.

The prognosis for individuals with B-cell acute lymphoblastic leukemia depends on various factors such as the person’s age at diagnosis.

Children and young people are significantly more likely to undergo successful treatment and enter remission. For children with ALL, the 5-year survival rate is 85%. For adults with ALL, the 5-year survival rate is 69.9%.

A person’s white blood cell count at the point of diagnosis also plays a role. People with a lower white blood cell count are more likely to make a full recovery. Additionally, how well a person responds to chemotherapy affects their recovery.

People who have concerns about ALL should contact their doctor or healthcare practitioner for advice. Cancer facilities often have support staff who can direct people to resources and support.

In the United States, the Leukemia and Lymphoma Society and American Cancer Society offer support and information for people living with ALL and other types of leukemia.

B-cell acute lymphoblastic leukemia is one of the most common types of leukemia in children but is rare in adults.

Various treatments aim to put the individual in remission and typically involve an extended chemotherapy regime.

The outlook for individuals with B-cell acute lymphoblastic leukemia is improving, especially among children, who often make a full recovery.