Treatment of aggressive non-Hodgkin's lymphoma with chemotherapy in combination with filgrastim

Requirement for neutralizing antibodies to control bone marrow transplantation-associated persistent viral infection and to reduce immunopathology

Bone marrow transplantation (BMT) is commonly used in the treatment of leukemia, however its therapeutic application is partly limited by the high incidence of associated opportunistic infections. We modeled this clinical situation by infecting mice that underwent BMT with lymphocytic choriomeningitis virus (LCMV) and investigated the potential of immunotherapeutic strategies to counter such infections. All mice that received BMT survived LCMV infection and developed a virus carrier status. Immunotherapy by adoptive transfer of naive splenocytes protected against low (200 PFU), but not high (2 x 10(6) PFU), doses of LCMV. Attempts to control infection of high viral titers using strongly elevated frequencies of activated LCMV-specific T cells failed to control virus and resulted in immunopathology and death. In contrast, virus neutralizing Abs combined with naive splenocytes were able to efficiently control high-dose LCMV infection without associated side effects. Thus, cell transfer combined with neutralizing Abs represented the most effective means of controlling BMT-associated opportunistic viral infection in our in vivo model. These data underscore the in vivo efficacy and immunopathological "safety" of neutralizing antibodies.

The interplay between c-Myc oncogene expression and circulating vascular endothelial growth factor (sVEGF), its antagonist receptor, soluble Flt-1 in diffuse large B cell lymphoma (DLBCL): relationship to patient outcome

The c-Myc is a ubiquitous and multifunctional oncogene. Recently, data obtained from experimental study suggests the involvement of c-Myc oncogene in angiogenesis. In the present study the interrelation of sVEGF, sFlt-1 concentrations and c-Myc oncoprotein expression at diagnosis were assessed in DLBCL and their impact on the patient outcome. Forty-five DLBCL patients beside 10 normal controls were included. C-Myc oncoprotein was assessed by immunohistochemistry. SVEGF and sFlt-1 were determined by enzyme linked immunosorbent assay. C-Myc over-expression was detected in 66.6% of DLBCL. The DLBCL patient group with positive c-Myc over-expression showed significantly higher sVEGF and significantly decreased sFlt-1 as compared to group with negative c-Myc over-expression (P = 0.000 and P = 0.009 respectively). SVEGF was positively correlated to sLDH and s.beta2 microglobulin (r = 0.6, P = 0.000, r = 0.69, P = 0.000) respectively. On the other hand sFlt-1 was negatively correlated to sLDH and s.beta2 microglobulin (r - 0.25, P > 0.05, r - 0.49, P = 0.001) respectively. The non-living DLBCL group showed significantly higher expression of c-Myc, higher concentration of sVEGF and lower concentration in sFlt-1 level as compared to the living group (P = 0.000 for all). Multivariate analysis revealed that c-Myc over-expression; high sVEGF and normal sFlt-1 levels at diagnosis had independent adverse influence on survival (relative risk: 17.9, 35.7, 29.3, 2.63; P < 0.0001, P < 0.0001, and P = 0.03 respectively)

IN CONCLUSION

C-Myc over-expression significantly associated with high sVEGF and normal sFlt-1 level in DLBCL patients, suggesting a complex interrelationship between c-Myc oncogene expression and angiogenic regulators. C-Myc over-expression, high sVEGF and normal sFLt-1 levels at diagnosis had an independent adverse influence on survival in DLBCL patients and considered bad prognostic markers.

Current treatment options in aggressive lymphoma

The overall percentage of patients achieving long-term remissions in aggressive non-Hodgkin's lymphoma (NHL) using CHOP or CHOP-based primary chemotherapy is only 40%. Much effort has therefore been concentrated on developing strategies to improve this figure. More intensive variants of CHOP chemotherapy, such as multi-agent "third-generation" regimens, have failed to improve long-term survival, and are also associated with increased toxicity. Hence, there is a need for improved treatment regimens, both as primary therapy and for patients in first and subsequent relapse. This need is most acute in elderly patients (> 60 years of age), who comprise more than 50% of NHL cases and who may not be able to tolerate subsequent intensive chemotherapy at relapse. Approaches currently being examined to improve outcome include: the use of clinical, histological and molecular prognostic factors to establish a patient's risk group, and so define those patients most likely to benefit from early aggressive therapy; the inclusion of high-dose therapy and autologous transplantation; and the integration of novel therapies, such as immunotherapy and radioimmunotherapy, into existing treatment strategies. The impact of these approaches on the treatment of diffuse, large B-cell lymphoma and mantle cell lymphoma is discussed below.