Low apoptotic index & bak expression in EBV-associated childhood classical Hodgkin lymphoma.

Background & objectives: Association of Epstein-Barr virus (EBV) with Hodgkin lymphoma (HL) is particularly high in low-income countries, and resistance to apoptosis might play a role in pathogenesis and survival. Data from previous studies are not consistent, and none is available in children. Thus this study was undertaken on Indian children with classical Hodgkin lymphoma to assess the significance of bcl-2, bak and p53 expression, and apoptotic index in relation with EBV status and treatment outcome with chemotherapy alone. Methods: Children (age<15 yr) with classical HL (n=143) were included in the study. Bcl-2, bak, p53, Ki67 and latent membrane protein-1 (LMP1) were detected by immunohistochemistry in pre-treatment lymph node biopsies. Apoptotic index was assessed by TdT-dUTP nick-end labelling (TUNEL). Results: Bcl-2, bak, p53 were expressed above positivity threshold in 83.3, 94.0 and 7.1 per cent of the cases respectively. More than 10 per cent of apoptotic tumour cells were seen in 60.4 per cent of the cases. 131 (91.6%) cases were EBV associated. EBV-positive cases had a significantly lower mean bak expression (p=0.001) and a lower apoptotic index, without higher proliferation index. Advanced stage showed a borderline association with bcl-2 expression in >25 per cent of tumour cells and p53 negative tumours. In univariate analysis, p53 positive cases, which were significantly associated with B symptoms, had a poorer overall survival (P=0.03) while low proliferation index was associated with poorer failurefree survival. Neither EBV status nor any of the apoptotic parameters studied showed independent association with survival. Interpretation & conclusion: EBV detection in children with classical Hodgkin lymphoma was associated with significant lower bak expression and with lower spontaneous apoptosis of H-RS cells suggesting that EBV-LMP1 might downregulate bak pro-apoptotic protein. this needs to be substantiated further.

Epidemiology of childhood Hodgkins disease: is it different in developing countries?

Childhood Hodgkins Disease (HD) is a lymphoma that displays characteristic epidemiological, clinical and pathological features according to various geographic areas, particularly according to the socio-economic level of a given country. India presents a similar sex, age and subtype distribution as other emerging countries: high male-to-female ratio, younger age at presentation, high proportion of advanced stages and presence of constitutional symptoms, predominance of mixed cellularity type of HD. The etiology of HD is still the subject of controversy and investigation, but it may occur as a sequel of a viral infection during early childhood, such as Epstein-Barr virus (EBV). Most cases of Indian childhood HD are associated to EBV, while genetic predisposition is seen in very rare cases.

Current strategies in the treatment of childhood Hodgkins disease.

Dramatic changes in the treatment of childhood Hodgkins disease have taken place during the past three decades. Contemporary combined modality treatment regimens produce durable disease-free survival in 90 to 100%of patients with early disease and in 70 to 85%of patients with advanced disease. Studies using chemotherapy alone also report high survival rates, and current studies are few to highlight the superiority of chemo-radiotherapy vs. chemotherapy alone. After the prodigious improvement achieved in response and survival rates, current strategies aim at reducing late effects of therapy, reserving more aggressive treatment modalities for patients with high risk features.