Unfortunately for Taylor her flow cytometry tests do indeed

Unfortunately for Taylor, her flow cytometry tests do indeed suggest she has CLL. Taylor\'s immediate thoughts a about possible treatments and what they will mean for her and her family. Dr Chavez tells her that she will need to undergo further tests to determine the best course of treatment, but that some CLL patients receive antibiotics to help treat infections, and blood transfusions or red cell growth factors to help increase the red blood cell count and reduce the symptoms of anemia. In addition, the doctor mentions there are chemotherapeutic agents available to treat the cancerous B cells, including Rituxan\". Taylor has heard horror stories about chemotherapy and as Dr. Chavez how Rituxan works. Dr. Chavez begins by explaining that unlike most chemotherapeutic agents, which act broadly to target and destroy all apid dividing cells, restricted to B cells. is the trade name for Rituximab the \"mab\" at the end refers to its being a monoclonal antibody that targets the CD20 molecule on B cells (both healthy and cancerous). Normally antibodies function to tag a virus or bacterial cell, thus helping the rest of the immune system destroy and clear the target. In

Solution

The given question illustrates the course of treatment and diagnosis of a patient called Tayor, suffering from pediatric acute lymphoblastic leukemia (ALL). Dr. Chavez prescribes the medicine, called Rituxan (trade name rituximab) and ensures Taylor that this will not cause severe side effects like other chemotherapeutic drugs.

9. The CD20 molecule is a protein expressed on the surface of B cells, both pre-B cells and mature B cells present in the bone marrow and periphery. The CD20 molecule is not present on hematopoietic cells and plasma cells circulating the body. In ALL, there is cancer of the bone marrow, leading to the uncontrolled division of the lymphoblast. This results in the CD20 expressing B cell lineage proliferating beyond control. These cancerous cells are unable to fight infections, compete with healthy blood cells and cause anemia and bleeding.

The drug Rituxan is a genetically engineered monoclonal antibody which acts against the B cell lineage-specific CD20 antigen. Upon administering Rituxan, these cancerous cells are killed by ADCC or complement mediated cell lysis. The advantage of using Rituxan is that it does not target the hematopoietic stem cell and plasma cells.

The hematopoietic precursor cells can regenerate the depleting B-cells and the plasma cells can provide for the immunoglobulins needed.

10. b.

10. c.

The lymphoblast present in the bone marrow is responsible producing B cells, T cells, and Natural killer cells. In ALL, there is expansion of B cell lineage which present CD20 molecule on their cell surface.

The basis of differentiation is the presence of different CD cell surface factors on T cells and B cells. The B-cells contain CD19 markers and T cells contain CD3 markers.

Fluorescently tagged antibody designed for these CD markers can be used and can be viewed using microscopy techniques.

Bone marrow of healthy donor	Bone marrow of ALL patient
Lymphoblast cells are in normal range	Lymbhoblast cells are in excess
RBC, monocyte, plasma cells present	RBC, monocyte, and plasma cells are absent
Granulocytes are in normal range	Granulocytes are fewer than normal