Chronic lymphatic leukemia

Leukocytes or white blood cells are the cells that participate in the defense of the body. Within the leukocytes we find different types, such as lymphocytes or monocytes, each of them with a specific function within the immune system.

Leukocytes originate in the bone marrow, from immature cells called blasts that differentiate to create the various types of leukocytes. When a loss of the control mechanisms of the proliferation of these white blood cells occurs, due to different causes, it is called leukemia, that is, a cancer of leukocytes and their precursor blasts.

Depending on the type of blasts involved in the leukemia, lymphatic leukemias are distinguished, if lymphoblasts, the precursors of lymphocytes, or myeloid leukemias, if they are the precursors of red blood cells, platelets and the rest of leukocytes, cells that cause cancer.

Likewise, depending on its establishment and the proportion of mature and immature cells that intervene in leukemia, it can be acute, with a predominance of immature forms and a rapid evolution, or chronic, with a greater number of mature cells and a slower progression.

Therefore, when a patient suffers from hematological cell cancer where there is a predominance of mature lymphocytes, said pathology will be classified as chronic lymphatic leukemia.

How is it produced?

Most of these chronic lymphatic leukemias are of unknown origin, although it is true that there is a family incidence. It is the most frequent of the leukemias in the West and presents a clear predominance in advanced ages, above 60 years in general, and in men. It constitutes a quarter of the total of the leukemias that are diagnosed.

It is usually a cancer of type B lymphocytes that present immunological defects, both in terms of the immunoglobulins that are found on their surface and allow them to recognize antigens and in their ability to produce antibodies and respond appropriately to the factors that stimulate their reproduction. an activation of the immune system. For this reason, despite the fact that there is a high number of lymphocytes in the blood, the body's immune capacity is diminished.

There is a special form of chronic lymphatic leukemia in which the lymphocytes that are affected by cancer have elongated and narrow projections of their cytoplasm, as if they were hairs, which is why this type of hematological cancer is called hairy cell leukemia or hairy cell leukemia (from the Greek trika, hair).

Chronic T-cell lymphatic leukemias are much less common. Of particular note are adult T leukemia or large granular T-cell lymphocytosis.

Symptoms

In the initial stages of the disease, more than 70% of patients do not present any type of symptoms. As the disease progresses there is a picture of tiredness, weakness, weight loss and lack of appetite. Tiredness can be aggravated by a state of anemia.

When there is a large proliferation of altered lymphocytes, autoimmune situations can occur, that is, these cancerous lymphocytes produce antibodies against the body itself, usually against red blood cells and platelets, which can lead to phenomena of hemolytic anemia or autoimmune thrombopenia. In advanced stages, due to this lack of platelets, bleeding and bruising can occur, as well as recurrent infections due to the malfunction of the immune system.

The altered lymphocytes invade other organs, especially lymph nodes, causing adenopathy, and also the liver or spleen, resulting in hepatomegaly and splenomegaly.

It is not common, but sometimes chronic lymphatic leukemia can transform into another entity, such as large cell lymphoma, a very aggressive lymphoma; This transformation is called Richter syndrome and occurs in 3-4% of cases.

The most frequent transformation is in prolymphocytic leukemia, which occurs in 10-20% of cases in which there is transformation. In any case, these transformations are rare, since most patients end up dying from the tumor or from the immunosuppression caused by the malfunctioning of the immune system.

Hairy cell leukemia is characterized by pancytopenia, that is, a decrease in all hematologic cell lines (red blood cells, leukocytes, and platelets) and massive splenomegaly. It is usually associated with autoimmune vasculitis, especially panarteritis nodosa.

Diagnosis

The diagnosis of chronic lymphatic leukemia will be based on laboratory tests and a bone marrow biopsy. In a large number of cases, the diagnosis will be made by a casual finding of high numbers of lymphocytes when performing a blood test. In the same analysis, a decrease in both platelets and red blood cells can be detected in advanced stages.

Chronic lymphatic leukemia should be suspected in elderly patients who present with fatigue, weakness, and loss of weight and appetite with no other apparent cause. Likewise, it should be taken into account as a diagnosis in patients in whom an increase in the size of the liver, spleen or both is explored or referred.

A peripheral blood smear will be made to be able to study the cells and see their alterations. It is very common to find that when the blood is spread for microscopic observation, the lymphocytes break, giving rise to forms called Gumprecht spots or shadows.

When performing a bone marrow puncture, generally at the level of the sternum or iliac crest, it will be observed that more than 40% of the cells that occupy it are type B lymphocytes.

In the same way, it will be seen how these cells invade the interstitial space, respecting or not the fat that divides the spaces where blood cells are created. There are genetic and cytological tests that allow characterizing cell proliferation as typical of chronic lymphatic leukemia.

It should be said with regard to hairy cell leukemia that the diagnosis will be based on the visualization of the characteristic hairy cells in the blood and on the bone marrow aspirate, which is usually dry, that is, with little collection of hematological material due to the great fibrosis that occurs, a fact that will make a bone marrow biopsy essential.

Imaging tests such as computerized axial tomography (CT) and ultrasound will make it possible to assess the presence or absence of lymph node, liver or splenic involvement.

There are two classifications of the evolution of chronic lymphatic leukemia, stages that are relevant since they imply differences in the mean survival of the patients. The international system is based on the number of lymphatic areas involved, as well as the presence or absence of anemia, thrombopenia, hepatomegaly, and splenomegaly. Rai's classification, for its part, classifies the disease into:

• Stage 0, only with the presence of more than 15,000 lymphocytes / mm3.
• Stage I, with added lymphadenopathy.
• Stage II, with hepatomegaly, splenomegaly, or both.
• Stage III, with a hemoglobin lower than 11 mg / dl in men and 10 mg / dl in women.
• Stage IV, with platelets below 100,000 / mm3.

Stage 0 means a survival of about 14 years, stages I and II about 7.5 years, and stages III and IV about 2.5 years.

Treatment

If there are no symptoms, therapeutic abstention is preferred. At the onset of symptoms, chemotherapy treatments will be performed, sometimes associated with radiotherapy, splenectomy or immunoglobulin treatments. If possible, bone marrow transplantation can be considered.

In the case of hairy cell leukemia, the removal of the spleen is usually chosen since most of the tumor mass is usually found in this organ. Treatment with chemotherapy and interferon is also offered.

Precautionary measures

Given the unknown origin in most cases of this entity, there are no preventive measures against it.