Comparison of response to chemotherapy in non-Hodgkin lymphoma patients depending on their myeloid derived suppressor cell status: Insight on new immune target.

Abstract

e23155 Background: Non Hodgkin’s Lymphoma shows different disease status after completion of standard 1st line treatment. Low grade follicular lymphoma remains stable after standard treatment for a long time and some times it autoregress . In High grade Lymphoma (Commonly diffuse B-cell lymphoma) relapsed 30-40% after 1stline treatment. Immunological target for this differentiation in tumor biology is sought for. Methods: Twenty Five CD20+NonHodgkin's Lymphoma(NHL) patients and one T cell lymphoma were treated with standard chemotherapy (6-8 cycles of RCHOP/CHOP). Within these 25 patients, 10 patients were disease free or exhibited stable disease for two years following the completion of treatment. Rest of the patients showed early relapse (within 6 months) or late relapse (within 18 to 24 months). Eight among 10 disease free patients was suffering from NHL of low grade follicular type. In order to correlate the immune cell status with lymphoma relapse, we have studied a panel of T cells, memory T cells, suppressor cells, after completion of chemotherapy and subsequently in every 6 month interval till relapse. Among several parameters studied a direct correlation between myeloid derived suppressor cells (MDSCs) profile and relapse was noted. Results: CD33+CD11b+MDSCs were remarkably high in high grade NHL patients in comparison to disease free low grade follicular lymphoma patients (p < 0.01). Moreover, all of these NHL patients possessed significantly greater proportion of MDSCs than normal healthy individuals (p < 0.001). Interestingly, single responding T cell lymphoma patient showed completely normal level of MDSCs. Studies are also being conducted to correlate with the status of memory T cells with disease relapse. Conclusions: Observed correlation between greater proportions of MDSCs with the relapse of diseases suggest MDSCs might be the potential target to enhance the relapse free survival of NHL patients, thus, demands further extensive investigation.