Molecular frequency of BCL2/JH t(14; 18) using PCR among Lebanese patients with follicular lymphoma: another piece of the geographical map revealed

Abstract

In follicular lymphoma the frequency of translocation t(14;18) varies considerably across different geographic regions ranging from up to 89% among the American follicular lymphoma to around 30% in the Japanese lymphoma. Neighboring and regional countries varied in their frequency reporting like in Israel (22 of 36 cases; 61%), Turkey (46 of 67 cases; 68.7%), and Jordan (4 of 5 cases; 80%). To our knowledge, this is the first study conducted in Lebanon to determine the frequency of this translocation in follicular lymphoma patients. Of 42 cases diagnosed with follicular lymphoma at the American University of Beirut Medical Center, amplifiable DNA was extracted from the corresponding paraffin embedded tissues and tested for t(14; 18) translocation using PCR amplification of the MBR and MCR breakpoints (INVIVOSCRIBE, CA, USA). We found that 19 patients were positive for t(14; 18) (45.2%) while 23 were negative (54.8%). Among the 19 positive cases, bcl2 was positive in 10 cases (52.6%). The majority of the cases were positive for MBR (40.47%), while only two cases were positive for MCR (4.76%). This study expands the geographical map of the distribution of bcl-2 gene rearrangement in follicular lymphoma patients in the Middle East region. The interesting low frequency of t(14;18) in Lebanese follicular lymphoma patients (45.2%) stands out among several other increased frequencies in surrounding and regional countries. In addition, in this patient population, there is a decreased frequency of the MBR breakpoint (40.47%) while that reported in the literature ranges from 50 to 60%.