Lack of Bcl‐2 expression in follicular lymphoma may be caused by mutations in the BCL2 gene or by absence of the t(14;18) translocation

• DOI: 10.1002/path.1689
• Publication Date: 2005-01-28T15:17:37Z
• Authors: Margit Schraders; Daphne de Jong; Philip Kluin; Patricia Groenen; Han van Krieken
• Keywords: Follicular lymphoma

Follicular lymphoma (FL), except grade 3B, is characterized by the chromosomal translocation t(14;18)(q32;q21), which results in over-expression of Bcl-2 protein. Ten per-cent all FLs, however, do not show protein expression with standard immunohistochemistry using a monoclonal antibody against residues 41-54 In this study, biological background 18 Bcl-2-negative FL cases I, II, or IIIa was investigated immunohistochemical staining and western blot analysis alternative antibodies. demonstrated five these carried t(14;18) translocation. Of 13 that were negative antibodies, 12 lacked PCR subsequent sequence cDNA three contained somatic mutations translocated BCL2 gene, resulting amino acid replacements region epitope recognized antibody. conclusion, majority lack but significant subset tumours are false due to gene. These findings may have consequences for use diagnostic purposes.