Association Between Complete Blood Cell Count (CBC)-Derived Inflammatory Markers and Natural Killer Cell Activity: A Cross-Sectional Study

Introduction: This study investigated the association between natural killer cell activity (NKA) and five complete blood cell count (CBC)-derived inflammatory markers, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and systemic inflammation response index (SIRI). Methods: This cross-sectional study included a total of 10,329 individuals who underwent CBC and NKA tests at Chaum Life Center in Korea between January 2016 and May 2022. NKA was estimated by measuring the amount of interferon-gamma (IFN-γ) released by activated natural killer cells; low NKA was defined as IFN-γ level