A phase I/II study of adoptive immunotherapy using donor liver graft-derived natural killer cells to prevent bloodstream infection after liver transplantation: a study protocol

Abstract Background Bloodstream infections (BSIs) are among the most lethal complications of liver transplantation (LT). Natural killer (NK) cells are an important component of innate immunity and play an essential role in infection and cancer. Adoptive transfer of activated NK cells has the potential to decrease post-LT infections, including BSIs. Methods In this prospective, single-center, interventional, single-arm, historical control, phase I/II study, 37 LT recipients will enroll. The patient will receive a single infusion of donor liver-derived NK cells 3−5 days after LT. Discussion The primary endpoint is the incidence of BSIs during the first month after LT. Secondary endpoints include overall survival, adverse events, immunological responses, hepatocellular or de novo malignancy, and incidence of infectious disease. Trial registration This study was prospectively registered with UMIN000019183 ( https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000022074 ) on November 1, 2015 and jRCTa060190036 on February 27, 2020.