A new multi-parameter flow cytometric assay for monitoring lymphoma growth and spread in a pre-clinical murine model for human lymphoma

Background: Mouse survival is commonly used as an indirect measure of lymphoma tumor response to anti-idiotype vaccine; however, this gives no information regarding residual lymphoma cells at primary or metastatic sites. We aimed to develop a method with which to monitor lymphoma tumor kinetics in the mouse as an independent measure of vaccine efficacy. Methods: We developed a multi-parameter flow cytometric (MPFC) assay for 38C13 mouse lymphoma cells using sequential gating to detect aberrant antigen expression and binding by an anti-idiotype antibody (S1C5). Subsequently, we tested the utility of the MPFC assay in a 38C13 tumor modeling study in the C3H/HeN mouse. Results: The MPFC assay was demonstrated in vitro to have both high specificity and sensitivity for 38C13 lym- phoma cells. In tumor kinetic studies in the C3H/HeN mouse, as the tumor enlarged, the MPFC assay showed increasing prevalence of 38C13 cells at the inoculation site in addition to metastases to lymphoid organs and bone marrow. The latter findings were confirmed by both histology and immunohistochemistry. Conclusions: The MPFC assay is an independent parameter for monitoring 38C13 lymphoma kinetics and could be used to monitor tumor response to individual vaccines or other lymphoma therapy prior to clinical trials. (C) 2004 Wiley-Liss, Inc.