Prognostic Significance of Cell Proliferation and Apoptosis-Regulating Proteins in Epstein-Barr Virus Positive and Negative Pediatric Non-Hodgkin's Lymphoma

Apoptosis-related proteins and proliferation activity and their relationship with Epstein-Barr Virus (EBV) are contemporary issues in pediatric non-Hodgkin's lymphoma (pNHL). In this study prognostic or pathogenetic role of EBV latent infection, proliferating activity, and apoptosis-regulating proteins in pNHL were explored. EBV-EBER, lmp-1, ki-67, bcl-2, survivin, bax, fas, c-myc, p53 and apoptotic index by TUNEL method were explored in 70 pNHL cases and evaluated statistically. Of the 70 cases evaluated, 24 were female and 46 were male. Seven cases were stage I/II and 63 cases were stage III/IV. The mean age was 7.16 +/- 3.72(1-15). EBV was positive in (25.7%) cases. Overall survival was 82%, while event free survival was 75%. Bax was expressed in 40% of the cases, while the expression of bcl-2, was 50%, survivin 42.9%, p53 8.6%, fas 18.6% and c-myc in 45.7%. Mean apoptotic index was 131.29 +/- 96.69 per 5,000 cells. Mean proliferation index was 55.97% (12-92%). Fas positivity was high in EBV positive cases (p=0.0001). EBV positivity was not related with prognosis. Apoptotic index was found to be an independent prognostic factor (p=0.017). Our results suggest that apoptosis-regulating proteins have a role in the pathogenesis of pNHL. EBV was correlated with apoptotic index and fas, bcl-2. No correlation was observed with proliferation index and studied factors. High apoptotic index was related with good prognosis