Abstract: Objective To observe the safety and efficacy of natural killer (NK) cell transfusion in the treatment of malignant liver tumors. Methods Ten patients with malignant liver tumors that had been treated by operation, transcatheter arterial chemoembolization (TACE) or microwave ablation were enrolled in this study. They received transfusion therapy with NK cells derived from their immediate family. The safety and short-term efficacy of this treatment was evaluated by observing the patients’response to transfused allogeneic NK cells, and the changes of life quality (KPS score),liver and kidney function, blood routine, circulating tumor cells (CTC),overall remission rate, overall survival rate and other indicators before and after the treatment. Results (1) After allogenic NK cell transfusion, one patient developed chills with chest tightness at half an hour post cell infusion and received symptomatic treatment. After 15 minutes, the symptoms were relieved and the temperature rose to the highest of 39.9℃, accompanied by nausea and vomiting. After being treated with Metoclopramide and Tylenol, the symptoms gradually disappeared and there was mild muscle soreness at the next day. One case had insomnia. The mental, appetite and physical strength of 5 patients improved significantly;(2) The number of CTC measured at 24 hours after infusion in 10 patients was lower than that before transfusion and the difference was statistically significant (P< 0.05). There was no significant change in liver and renal function;(3) Patients were followed up for 3 ~ 36 months. According to the Response Evaluation Criteria in Solid Tumors (mRECIST:complete response=CR,partial response=PR,stable disease=SD;progressive disease=PD), the 3-month overall survival rate was 100%,effective response rate was 80%(no death,2SD,3PR, 5CR); the 6-month overall survival rate was 90%,effective Response rate was 80%(1 death,1PD,3PR,5CR);overall survival rate at 12 months was 80%,effective response rate was 60% (2deaths,2PD,3PR,3CR);overall survival rate at 36 months was 50%, and effective response rate was 30% (5 deaths,2PD,3CR). Conclusion NK cells transfusion in the treatment of malignant liver tumors has good clinical safety. The treatment may improve the short-term quality of patients’ life, improve clinical symptoms and thus has certain clinical value in the treatment of malignant liver tumors.

Key words: Natural killer cell, Cell therapy, Liver malignant tumors