Xiaoju Lü
Sichuan University, China
Title: Plasma levels of interleukin-17 and natural killer cell in patients with multidrug resistant Acinetobacter baumannii pneumonia: possible role for the interleukin-17/ natural killer cell axis
Biography
Biography: Xiaoju Lü
Abstract
Natural killer (NK) cells are crucial for antibacterial defense. Interleukin (IL)-17 family cytokines affect the immune system and have a role in NK cell development. We hypothesize that the IL-17-NK cell axis may impact immunity against bacteria. This study aims to investigate the role of IL-17-NK cell axis in patients with multidrug resistant Acinetobacter baumannii (MDRAB) pneumonia. Twenty-four adults hospitalized with MDRAB pneumonia and 20 healthy controls were enrolled in this study. Plasma levels of IL-17, NK, granulocyte macrophage-colony stimulating factor (GM-CSF) and macrophage inflammatory protein (MIP)-1α were measured by ELISA. The peripheral blood T lymphocyte subsets were analyzed by flow cytometry. The clinical outcomes of these patients were recorded. The plasma IL-17, NK, GM-CSF, MIP-1α and PCT levels of patients with MDRAB pneumonia were lower than that of control group (P<0.05). Furthermore, it was found that IL-17 levels in plasma are positively correlated with NK, GM-CSF or MIP-1α levels. However, there was an immunocompromised MDRAB pneumonia patient with a CD4 count of 53 and CD8 count of 46, his plasma IL-17, NK, GM-CSF and MIP-1α levels were significantly elevated, and several days later he died. Cytokine storm might be associated with his death. In conclusion, the reduced IL-17 and NK levels might be one of the cause of MDRAB pneumonia. Different immune response produced by infection in patients with different immune function. The regulating mechanism of IL-17-NK cell axis should be studied further. IL-17-NK cell axis may be a potential therapeutic target of MDR bacterial infection treatment.