BCL2 (SP66)

BCL2 is a protein associated with apoptosis regulation produced by the bcl-2 gene, located on chromosome 14q32.1 BCL2 is comprised of an alpha (239 amino acids) and beta chain. BCL2 (and thus BCL2 alpha chain) is found in mitochondrial and nuclear membranes and in the cytosol rather than the cell surface. In normal lymphoid tissue, BCL2 (and BCL2 alpha) antibody reacts with small B-lymphocytes in the mantle zone and many cells within the T-cell areas. Anti-BCL2 alpha has shown consistent negative reaction on reactive germinal centers and positive staining of neoplastic follicles in follicular lymphoma.2 This difference in staining pattern is not due to down regulation or decreased BCL2 mRNA, but largely to a post-translational mechanism with resultant decrease in protein levels. Consequently, this antibody is valuable when distinguishing between reactive and neoplastic follicular proliferation in lymphoid lesions. Anti-BCL2 has been used as an indicator of minimal residual disease in the bone marrow of follicular lymphoma patients when staining is strong and uniform.3