[Proliferation and apoptosis in primary gastrointestinal B-cell non-Hodgkin s lymphoma and its association with Helicobacter pylori].

Objective: To investigate primary gastrointestinal B-cell non-Hodgkin s lymphoma for clinicopathological features, proliferation, apoptosis and its association with Helicobacter pylori (HP).

Methods: Classification of tumors, expression of HP, proliferation and apoptosis related gene products were studied by immunohistochemistry. Apoptosis was studied by TUNEL (TdT [terminal deoxynucleotidyl transferase] dUTP nick end-labeling).

Results: There were 15 cases of mucosa associated lymphoid tissue (MALT) lymphoma (9 in stomach, 6 in intestine) and 42 cases of diffuse large B cell lymphoma (DLBCL) (28 in stomach, 14 in intestine) in all the 57 cases of primary gastrointestinal BCL. The average apoptotic indexes (AI) were 0.16%, 2.54% in MALT lymphoma and DLBCL respectively. The average proliferation indexes (PI) were 2.22% and 8.71%,respectively. The p53 positive rates were 6.7% and 35.7%. PI (P=0.026) and p53 (P=0.044) had significant differences; But Bcl-2 positive rates were 60.0% and 35.7%,and HP positive rates were 66.7% and 23.8%, respectively. HP had significant differences (P=0.005).

Conclusion: HP and gastrointestinal MALT lymphoma had significant relation. Apoptosis and proliferative activity were higher in DLBCL than in MALT. The higher Bcl-2 expression in MALT may be related to lower apoptosis. p53 promotes apoptosis and p53 gene mutation may play a role in the progression from MALT to DLBCL. HP antibody may be used in HP detection in gastrointestinal BCL.