Chronic lymphocytic leukaemia (CLL) is cancer of the white blood cells. It affects the types of white blood cells called lymphocytes. CLL tends to progress slowly over the course of many years. It is more common in older people. It is often without symptoms and picked up on a blood test done routinely or for something else. Although CLL is not a curable condition, for the majority of our patients it is possible to have a good quality of life.

In its early stages, CLL doesn't usually cause any noticeable symptoms. As the condition develops, symptoms can include:

  • repeated infections that occur over a short period of time and may require antibiotics
  • tiredness or breathlessness which may be due to a lack of red blood cells (anaemia)
  • unusual bleeding and bruising
  • unexplained fevers
  • drenching night sweats
  • unintentional weight loss
  • swollen spleen which may manifest itself in feeling full after only eating small amounts, or discomfort or pain in the abdomen
  • swollen lymph nodes (glands), especially around the neck or collar bone, armpits or groin

Bone marrow – the spongy material found inside bones – contains a specialised type of cell called stem cells. These stem cells can develop into any of the three types of blood cell:

  • red blood cells – which carry oxygen around the body
  • white blood cells – which help fight infection
  • platelets – which help stop bleeding

In CLL, the stem cells start overproducing white blood cells that aren't fully developed. These are called lymphocytes.

The overproduction of lymphocytes is at the expense of the other blood cells, and it is this lack of red blood cells and platelets that can cause symptoms of anaemia, such as tiredness, as well as increasing the likelihood of excessive bruising or bleeding due to low platelets.

The white blood cells are also not properly formed, and these immature lymphocytes are much less effective at fighting bacteria and viruses, making you more vulnerable to bacterial and viral infection.

In most cases, it is not known what causes CLL. However, CLL is the most common type of leukaemia in adults. There are a few known risk factors that may increase the chances of developing CLL, including:

  • having a family history of the condition
  • being of European, American or Australian origin (it is rare in people from China, Japan and South East Asia)
  • being male
  • being older

One of the main complications of CLL is increased vulnerability to infection. This is because your immune system will be weakened due to a reduced number of healthy, infection-fighting white blood cells. Having chemotherapy treatment will further weaken your immune system.

Due to the risk of infection, you should have vaccinations at your GP once you have a diagnosis of CLL. Evidence shows that some patients respond particularly well if they are vaccinated early in the disease and if conjugate vaccines (a type of vaccine that improves immune response) are used, particularly to streptococcus pneumonia and haemophilus influenzae B (Hib). Seasonal flu vaccination should also be given.

Around 10% of people with CLL will develop anaemia due to the breakdown of red blood cells. This form of anaemia is called autoimmune haemolytic anaemia and can be severe, causing fatigue and breathlessness. Steroids are often used to treat autoimmune haemolysis.

CLL can also transform into a faster growing disease, a Hodgkin’s or non-Hodgkin’s lymphoma called Richter’s transformation. This occurs in approximately 2% to 10% of CLL patients during the course of their disease, with a transformation rate of 0.5% to 1% per year. If this happens, we will explain the change in greater detail and discuss treatment options.

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