Abstract
Patients with sepsis face high mortality rates and a bleak prognosis, prompting the need for advanced therapeutic interventions. A male patient diagnosed with moderately low-differentiated squamous cell carcinoma received diverse treatments, including radiotherapy, chemotherapy, immunotherapy, and targeted therapy to inhibit angiogenesis. Subsequently, he developed sepsis after comprehensive treatment, and conventional antibiotic combinations proved ineffective in combating the infection. As an experimental approach, allogeneic natural killer (NK) cell infusion was administered. Following the NK cell infusion, the patient regained consciousness, and laboratory analyses showed reduced infection-related markers, suppressed serum inflammatory cytokines, and elevated anti-tumor cytokines. However, the therapeutic effect only lasted 2-3 days. In vitro investigations demonstrated that the allogeneic NK cell product reduced interleukin-6 levels in the patient's serum. Moreover, subsequent co-cultivation of the NK cell product with the patient's serum resulted in a decrease in the proportion of cytotoxic subpopulations of NK cells and a downregulation of the expression of NK-mediated killing molecules. In conclusion, adoptive transfusion of allogeneic NK cells may improve sepsis symptoms in patients with tumor-related sepsis. In vitro co-culture tests hold promise in providing predictive biomarkers for treatment effectiveness.