B Cell

What B Cells Are and Their Role in the Body

B cells, also known as B lymphocytes, are a type of white blood cell that plays a key role in your immune system. They develop from stem cells in the bone marrow, the soft tissue inside your bones. Their main job is to make antibodies—special proteins that recognize and help fight infections caused by bacteria, viruses, and other harmful substances. These antibodies can either be released into the blood or stay attached to the B cell’s surface to detect invaders. B cells also help alert other parts of the immune system to respond to threats.

Why B Cells Matter in Cancer Care

Sometimes, B cells can become abnormal and start growing uncontrollably. This can lead to cancers such as non-Hodgkin lymphoma, a cancer of the lymph system, which is part of the immune system. When this happens, the abnormal B cells crowd out healthy cells and affect how your body works. Symptoms may include painless swelling of lymph nodes in the neck, armpits, or groin, unexplained weight loss, fever, night sweats, and fatigue. Knowing whether cancer involves B cells helps doctors decide on the best treatment approach, which may include chemotherapy, radiation, or newer targeted therapies that aim to attack cancer cells while sparing healthy ones.

What Patients Might Experience and See When B Cells Are Discussed

If your doctor talks about B cells, it might be related to diagnosing or treating lymphoma or other immune-related cancers. You may hear about tests that look for abnormal B cells, such as biopsies or blood tests. Sometimes, special scans use medicines that attach to proteins on B cells to help find where cancer cells are in the body. For example, a scan using a medicine called 111In-ibritumomab tiuxetan targets a protein called CD20 on B cells to show lymphoma locations. This helps doctors plan treatment but is not itself a treatment. Hearing about B cells does not mean you have cancer—B cells are a normal and important part of your immune system.

How Doctors Use Information About B Cells

Doctors use knowledge about B cells to help diagnose lymphoma by examining tissue samples and blood tests. They also use targeted therapies that focus on proteins found on B cells, such as CD20, to treat certain lymphomas. Some treatments combine antibodies that attach to B cells with small amounts of radiation to kill cancer cells more effectively. In some cases, if lymphoma is slow-growing and not causing symptoms, doctors may recommend watchful waiting instead of immediate treatment. Understanding the role of B cells helps guide these decisions and tailor care to each patient’s needs.

Questions You Can Ask Your Care Team

If you want to learn more, you might ask your doctor or nurse: What role do B cells play in my diagnosis? How does this affect my treatment options? Are there specific therapies that target B cells? What tests will show if B cells are involved? These questions can help you feel more informed and involved in your care.

Remembering the Purpose of This Information

This information is meant to help you understand B cells and their connection to certain cancers. It does not replace personalized medical advice. Your healthcare team knows your unique situation best and can explain what B cells mean for your health. If you have concerns or questions, don’t hesitate to reach out to them. Talking openly with your care team is the best next step to understand how B cells relate to your diagnosis or treatment and what to expect going forward.