Abstract
Background
Intraoperative blood salvage (IBS) reduces exposure to allogeneic blood but is accompanied by concerns in oncologic surgery regarding the potential reinfusion of residual tumor cells and subsequent metastatic dissemination. The CATUVAB® procedure was developed to eliminate EpCAM-positive tumor cells from autologous erythrocyte concentrates (EC). As CATUVAB® requires integration of a leukocyte depletion filter (LDF), the present study aimed to evaluate whether three different commercially available LDF meet predefined safety and efficacy criteria within this procedure.Methods
In this prospective ex vivo study, intraoperatively collected blood from patients undergoing major oncologic surgery was processed using the CATUVAB® procedure in combination with one of three LDF (Fresenius BioR Flex AT, Haemonetics US RS1, Puriblood LRW-50-04-PS). The primary endpoint was depletion of EpCAM-positive tumor cells. Secondary endpoints included residual catumaxomab levels in the final EC and changes in proinflammatory cytokines (IL-6, IL-8, TNF-α, IFN-γ). Removal of EpCAM/CD133 double-positive cancer stem cells was explored in a subgroup.Results
Thirty-one patients were analyzed. EpCAM-positive tumor cells were detected in intraoperative blood in a substantial proportion of samples, with marked interindividual variability in tumor cell burden. After CATUVAB® processing and final filtration, no EpCAM-positive tumor cells were detectable in any EC, irrespective of the LDF used. EpCAM/CD133 double-positive cancer stem cells were also eliminated in the subgroup. Residual catumaxomab was detectable in a proportion of ECs but consistently remained below the predefined safety threshold of 70 ng per EC. IL-6 and IL-8 levels were markedly reduced during processing across all filter types, whereas tumor necrosis factor-α (TNF-α) and interferon-gamma (IFN-γ) were largely below detection limits.Conclusion
The present study demonstrates that the CATUVAB® procedure, in combination with different leukocyte depletion filters, achieved effective removal of EpCAM-positive tumor cells, accompanied by low residual catumaxomab levels and reduced pro-inflammatory cytokine concentrations. These findings support the feasibility of this approach; however, given the limited sample size and exploratory design, they should be considered preliminary and require confirmation in larger studies.