Leukemia: Nursing pathophysiology

Leukemia is a cancer of the blood forming tissues that disrupts the normal function of bone marrow. This disruption leads to the proliferation of immature white blood cells.

Leukemias are classified as acute or chronic and by the type of cells affected either myeloid or lymphoid. The four primary types of leukemia include acute lymphoid leukemia or a ll chronic lymphoid leukemia or CLL acute myeloid leukemia or aml and chronic myeloid leukemia or CML.

Now, bone marrow is a spongy tissue found in the center of most bones. It contains stem cells which are unspecialised cells that through a process called hematopoiesis, differentiate into functional cells such as red blood cells or RBC S white blood cells or WB CS, also called leucocytes and platelets.

Hematopoiesis is a continuous process that ensures there's a steady supply of cells to replace old and damaged cells. As far as WBCs go, there are several types which come from two distinct stem cell lines.

The lymphoid line and the myeloid line immature cells called blast cells are formed from these stem cell lines and further differentiate into functional WBC S.

In the lymphoid line. Lymphoblasts produce lymphocytes including B cells.

T cells and natural killer cells in the myeloid line. Myeloblasts produce neutrophils, eosinophils, basophils and monoblasts produce monocytes.

These cells function as part of the immune system, fighting infection and other diseases and removing foreign substances from the body.

While the exact cause of leukemia is not fully understood. Genetic and environmental factors play a role.

Inherited genetic conditions associated with an increased risk of leukemia, include down syndrome and neurofibromatosis.

Other genetic changes such as chromosomal translocations where pieces of two chromosomes splitt off and swap places like with the Philadelphia chromosome are also associated with an increased risk of leukemia.

Environmental factors include exposure to ionizing radiation, cigarette smoke, and certain chemicals like benzene. In addition, epigenetic modifications like DNA methylation can also increase the risk of leukemia.

Lastly. A LL is more common in Children while CLL is more common in adults over the age of 65.

Now, whatever the cause immature blast cells that normally differentiate into functional WBC S don't mature and they're referred to as leukemic blasts.

These leukemic blasts multiply and begin to replace healthy bone marrow. As they accumulate in the bone marrow, they take up more and more space.

So the bone marrow becomes dense and packed with blast cells. A process called bone marrow crowding.

Eventually there isn't enough healthy bone marrow left to continue normal function and bone marrow failure occurs when this happens, it prevents the production of a sufficient number of WBCs RBC S and platelets which leads to decreasing levels of these cells and ultimately results in neutropenia, anemia and thrombocytopenia if that wasn't enough.

Once the blasts overwhelm the bone marrow, they can spread into the blood or they can deposit in tissues and organs like the lymph nodes, liver and spleen.

Clinical manifestations of leukemia are primarily related to bone marrow failure. Anemia can produce symptoms like pallor fatigue and shortness of breath.

Thrombocytopenia can cause problems with clotting, like excessive bruising, epistaxis and hematuria. And with leukopenia, there's immune dysfunction and increased risk of infections which can manifest as fever and fatigue.

Additionally, infiltration of blast cells into other body tissues can cause hepatosplenomegaly and lymphadenopathy as well as bone or joint pain and hypermetabolism related to rapid proliferation and destruction of leukemic blast cells can manifest as fever and unintentional weight loss.

Finally, since the leukemic blast cells die quickly, uric acid builds up in the blood which can cause hyperuricemia. All right.

As a quick recap leukemia is a cancer of the blood forming tissues that leads to the proliferation of leukemic blast cells which ultimately disrupts the normal function of bone marrow.

It's caused by a combination of genetic and environmental factors and clinical manifestations are related to bone marrow failure