It is believed that mutations to TP53 are responsible for the frequent therapy resistance and aggressive course of this disease. c-MYC Gene
In a small number of B-PLL cases, abnormalities in the c-MYC gene have been observed. It is considered a global amplifier and influences nearly all aspects of cellular activity. Among the number of genes it regulates, most are involved in cell growth, cell cycle progression, protein biosynthesis and apoptosis. Amplification of c-MYC has been reported in B-PLL patients and while the consequences are unclear, it is generally associated with poor clinical outcome. Biopsy
After physicians have identified an abnormality in the composition of the peripheral blood, biopsies (tissue samples) from a patients bone marrow and/or spleen are often recommended for confirmation. A bone marrow biopsy involves the removal of a small amount of tissue that is further analyzed for abnormalities, for B-PLL pathologists look for prolymphocytic infiltration where the hematopoietic stem cells of the bone marrow are replaced with prolymphocytes due to excess production. In 50% of reported cases, it was common for patients to be both anemic (lack healthy red blood cells in blood) and thrombocytopenic (deficiency of platelets in blood). Treatment
The rarity of B-PLL paired with its considerably fast progression compared to other leukemias has resulted in difficult production of effective treatments. This disease is currently incurable, treatments and therapy are guided to reduce prolymphocyte abundance in the blood and production by the bone marrow, treating symptoms and controlling progression.
Due to the similarities among lymphoproliferative disorders, it is often difficult to diagnose patients. Immunophenotyping helps distinguish B-PLL from similar diseases, one of its key identifiers is the absence in expression of the surface antigens CD10, CD11c, CD25, CD103 and cyclin D1 – an important regulator of cell-cycle progression.A case has been described as CD20+, CD22+, and CD5-.It can also be CD5+.Another case was described as CD45+, CD19+, CD20+, CD5+, HLA-DR+, CD10-, CD23+/-, CD38+ and FMC7-. Cytogenetics
B-PLL is rare, consequently few genetic studies have focused on this disease. As a result, the associated genetic lesions underlying B-PLL are largely unknown. Chromosomal Mutations
The most commonly reported abnormalities have occurred at chromosome 14, specifically in a region of the chromosome called band q23 (14q23). Translocations to this location lead to overexpression of the cyclin D1 gene which has been linked to both the development and progression of a number of cancers. Other chromosomal abnormalities have been reported on 6q21, 11q23, 12p12, 13q14 and 17p.It can involve deletions from chromosome 11 and chromosome 13. TP53 Gene
Among the documented studies, mutations to the TP53 gene have occurred in 75% of all cases of B-PLL. This is the highest incidence among all sub-types of B-cell malignancies. Mutations to this gene have also been documented in other hematologic malignancies.TP53 is an important transcriptional activator of genes involved in the regulation of the G1 checkpoint of the cell cycle as well as certain genes responsible for programmed-cell death (apoptosis).