Chronic lymphatic leukemia (CLL) is a cancer of the blood characterized by exaggerated production of B-lymphocytes. B lymphocytes protect the body against germs by producing proteins called antibodies.
In CLL, the abnormal B lymphocytes progressively infiltrate bone marrow, lymphatic tissue (lymph nodes and spleen primarily) and other organs such as the liver. The clinical manifestations of the disease are the result of these infiltrations that displace the normal elements of the blood, preventing the correct operation of the affected organs. In addition, the lymphocytes that are produced do not work properly and cannot fulfil their mission of defending the body.
Usually, the CLL affects people over 60 and progresses very slowly. In over 80% of patients, CLL is diagnosed through a routine blood test or accidentally, since it is usually totally asymptomatic. In all other cases, the main symptoms may include: weakness, adenopathies (enlarged lymph nodes) and repeated infections. It is not unusual to present splenomegaly (swelling of the spleen) or hepatomegaly (enlarged liver) that can cause abdominal discomfort. Unlike with lymphomas, fever, night sweats and weight loss are not frequent (10 %).
A blood test is enough to establish the diagnosis of CLL.
The prognosis of a patient with CLL is highly variable, depending on the presence or absence of a number of prognostic factors such as: the stage of the disease, the duplication time for the number of lymphocytes, the presence of certain cytogenetic abnormalities, and the increase in certain serologic markers.
5-10% of patients with CLL suffer an evolution towards an aggressive variety of lymphoma, called Richter syndrome, which requires intensive chemotherapy.
Patients with CLL in the initial phase do not normally require treatment for years and can lead a normal life. The criteria for initiating treatment are the presence of: very obvious systemic symptoms (fever, sweating, weight loss), lymphadenopathy or splenomegaly of large size causing discomfort, frequent or recurrent infections, progressive increase in anaemia and/or progressive decrease of the number of platelets and very fast duplication times for lymphocytes (less than 12 months). Very high counts of lymphocytes are not, by themselves, a criterion to start treatment.
These patients must receive treatment with one of the multiple chemotherapeutic schemes currently in use. None of these treatments leads to fully curing CLL, though the responses attained can be maintained for many years.
Unlike other leukemias, CLL is not usually treated with haematopoietic stem cell transplantation, due to the advanced age of most of the patients. In any case, young patients with aggressive CLL may benefit from this therapeutic measure if they have a compatible donor, as this is the only therapeutic option that allows the disease to be cured.