How does leukemia weaken the immune system?
Leukemia can weaken the immune system in several ways:
1. Malignant cell proliferation: In leukemia, there is an overproduction and accumulation of abnormal white blood cells, primarily immature lymphocytes (lymphoblastic leukemia) or myeloid cells (myeloid leukemia). These malignant cells can crowd out and suppress the production and function of normal immune cells, such as lymphocytes, neutrophils, and macrophages.
2. Impaired hematopoiesis: Leukemia affects the bone marrow, which is the primary site of blood cell production. The proliferation of leukemia cells disrupts the normal process of hematopoiesis, leading to a decrease in the production of healthy immune cells. This can result in reduced numbers of functional T cells, B cells, and natural killer (NK) cells, which are crucial for immune responses against infections and cancer cells.
3. Dysfunctional immune cell activity: Leukemia can impair the function and maturation of immune cells, even if their numbers are not significantly decreased. Malignant cells can release substances that disrupt the signaling pathways and communication between immune cells, affecting their ability to recognize and respond to foreign antigens and pathogens.
4. Splenomegaly and hepatomegaly: In some cases of leukemia, the spleen and liver become enlarged (splenomegaly and hepatomegaly). These organs play important roles in immune surveillance and the clearance of pathogens from the bloodstream. Their enlargement can impair their function and further weaken the immune system's ability to fight infections.
5. Increased risk of infections: As a result of the compromised immune system, individuals with leukemia are more susceptible to infections. They may experience recurrent or severe infections caused by bacteria, viruses, fungi, or opportunistic infections that take advantage of the weakened immune defenses.
6. Autoimmune disorders: Leukemia can also disrupt the normal immune regulation, leading to the development of autoimmune disorders. In these conditions, the immune system mistakenly attacks the body's own tissues, resulting in various symptoms and complications.
The weakened immune system associated with leukemia increases the risk of infections and other complications, contributing to the overall morbidity and mortality of the disease.