What is Chronic Lymphocytic Leukemia (Chronic Lymphoid Leukemia)?
The term chronic lymphocytic leukemia (chronic lymphoid leukemia, CLL), combines tumor diseases that are heterogeneous in their clinical, morphological and immunological characteristics, the development of which is based on the monoclonal proliferation of pathological lymphoid elements.
Among leukemia, in terms of structure and average annual incidence rates, chronic lymphoid leukemia takes the second place after acute leukemia.
Chronic lymphoid leukemia is often found among the population of European countries, Canada, USA, at the same time it is observed very rarely in countries of Southeast and East Asia. The disease is mainly registered in people older than 50 years. In patients aged 30-40, chronic lymphoid leukemia in 8.5% of cases and is extremely rare in adolescence and childhood. Among patients with a typical variant of the disease, men predominate (67.7%).
Causes of Chronic Lymphocytic Leukemia (Chronic Lymphoid Leukemia)
The relationship between the occurrence of the disease, mainly in people over 50, cases of familial CLL and other lymphoproliferative diseases in relatives of different generations or their detection in several family members are facts indicating the presence of genetic factors in the development of the disease.
Pathogenesis during Chronic Lymphocytic Leukemia (Chronic Lymphoid Leukemia)
Most cases of this disease are B-cell forms. Pathological lymphoid elements in this disease originate from a single progenitor cell, most of them contain monoclonal cytoplasmic immunoglobulin.
In CLL, B-lymphocytes do not differentiate until the formation of plasma cells that produce immunoglobulins, so patients with infectious diseases that often cause death. Along with the violation of antibody formation in the blood of patients, the titer of complement is reduced, to a lesser extent – 0-lysines.
Insufficient number and functional inferiority of T-lymphocytes determine the frequency of some viral diseases, severe reactions to vaccination. Violation of immunological homeostasis is the cause of autoimmune hemolytic anemia and thrombocytopenia detected in CLL in 13-15% of cases. Perhaps this is due to the high incidence of cancer in CLL. Finally, functionally inert lymphocytes with typical CLL, having a very long life cycle (months, years), accumulate in the parenchymal organs and organs of hematopoiesis, disrupting their function.
Along with typical CLL, its variants are distinguished – prolymphocytic, mainly splenomegaly, bone marrow, hairy, tumor, T-cell.