What is B-cell gene rearrangement?
B-cell immunoglobulin gene rearrangement tests are used to help diagnose non-Hodgkin B-cell lymphomas and evaluate for residual or recurrent disease after treatment. There are many different types of B-cell lymphoma and each has different characteristics, prognoses, and a likely response to therapy.
What is heavy chain rearrangement?
Immunoglobulin heavy-chain gene rearrangement begins in early pro-B cells with D to JH joining. This typically occurs at both alleles of the heavy-chain locus, at which point the cell becomes a late pro-B cell. The cell then proceeds to rearrange a VH gene segment to the DJH sequence.
How is B-cell differentiation linked with Ig gene rearrangement?
The differentiation of B lymphocytes from their progenitors progresses through a series of successive stages that are defined by sequential rearrangement of Ig loci and surface expression of various stage-specific markers, including Ig heavy and light chain proteins.
What is IgH testing?
The IgH Clonality by NGS test is designed to detect clonal populations of B-lymphocytes in a given patient sample through the analysis of the VDJ segment of the immunoglobulin heavy chain (IgH) gene. Detecting the presence of clonal B-lymphocyte populations is important for the diagnosis of B-cell lymphoma or leukemia.
What are B cells in CBC?
B Cells (100-600 cells/µL; 10-15% of total lymphocytes). These cells are produced from the pluripotent stem cells in the bone marrow and stay in the marrow to mature. B cells are in charge of antibody. Antibody binding alerts the immune system to target the bound molecule for destruction.
Which laboratory test is most appropriate for B-cell defect?
A commonly used test is called flow cytometry that can identify B-cells (and other kinds of lymphocytes) present in the circulation. The B-cell is the lymphocyte that has the ability to produce antibody.
What is the difference between light and heavy chains?
The light chain is made up of two such immunoglobulin domains, whereas the heavy chain of the IgG antibody contains four (see Fig. 3.1a). This suggests that the immunoglobulin chains have evolved by repeated duplication of an ancestral gene corresponding to a single domain.
Why is gene rearrangement important?
The rapid rate of gene rearrangement in mammals parallels both their rapid anatomical evolution and their rapid evolutionary loss of the potential for interspecific hybridization. Thus, gene rearrangements may be more important than point mutations as sources for evolutionary changes in anatomy and way of life.
What mechanism is used for the rearrangement of the heavy and light chain variable gene loci?
What mechanism ensures correct joining of gene segments during rearrangement of the heavy and light chain loci? Recombination signal sequences (RSS) – conserved sequences in regions just upstream or downstream of gene segments.
What happens in a productive rearrangement?
Productive rearrangement results in the successful synthesis and membrane expression of Ig. Productive rearrangement of one allele blocks the rearrangement of the other. If a developing B cell does not successfully rearrange one H and one L chain genes, it dies.
What do B-cells do in your body?
B cells create antibodies. B lymphocytes, also called B cells, create a type of protein called an antibody. These antibodies bind to pathogens or to foreign substances, such as toxins, to neutralize them. For example, an antibody can bind to a virus, which prevents it from entering a normal cell and causing infection.
How is the Ig heavy chain rearranged in B cells?
B Cells. During B cell development, rearrangement of the Ig heavy chain occurs first, commencing with D-J recombination, which takes place in the common lymphoid progenitors (CLPs) and pre-pro B cells. This is followed by V-DJ recombination yielding a functional heavy chain protein (Ig) in large pre-B cells.
Are B-cell receptor gene rearrangement studies useful in diagnosing diffuse large B-cell lymphoma?
The utility of B-cell receptor gene rearrangement studies in diagnosing diffuse large B-cell lymphoma with plasmacytic differentiation Ann Clin Lab Sci. Winter 2015;45(1):79-82. Authors Daisy V Alapat 1 , Jeanette M Ramos 1 , Julia Anderson 1 , Ginell R Post 2
What is the relationship between immunoglobulin heavy chain and Kappa genes?
Immunoglobulin heavy chain and kappa light chain gene rearrangement studies detected the same clone in the diagnostic and post-therapy lymph node specimens.
Is there an alternative to Southern blot hybridization for immunoglobulin heavy chain gene rearrangements?
Polymerase chain reaction (PCR) based assays were found to be a realistic alternative to Southern blot hybridization for the assessment of clonal immunoglobulin heavy chain gene rearrangements.