Characteristics of Immunocytes and Cytokines in Patients with Bloodstream Infections Caused by Carbapenem-Resistant Klebsiella pneumoniae in China

Wenhui Guo,1,* Xiang Lian,2,* Hong Li,2 Lushun Jiang,1 Yingsha Chen,3 Ping Shen,1 Wei Yu1 1State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China; 2Department of Infectious Diseases, The Affiliated Xiangshan Hospital of Wenzhou Medical University; Xiangshan First People’s Hospital Medical and Health Group; Ningbo Fourth Hospital, Ningbo, People’s Republic of China; 3Department of Infectious Diseases, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ping Shen; Wei Yu, State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China, Tel/Fax +86 571 87236421, Email shenping123451@126.com; wyu@zju.edu.cnObjective: To evaluate the characteristics of immunocytes and cytokines associated with bloodstream infections (BSIs) caused by carbapenem-resistant Klebsiella pneumoniae (CRKP).Methods: Patients with BSIs K. pneumoniae (BSIs-Kpn) were enrolled in our hospital between 2015 and 2022. Whole blood and serum samples were collected on the first day after diagnosis. Immunocytes and cytokines profiles were assessed using multicolor flow cytometry and multiplex immunoassays, respectively. The test cytokines included interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-2, IL-4, IL-6, IL-10, and IL-17A.Results: A total of 313 patients had BSIs-Kpn, including 145 with CRKP, 43 with extended-spectrum β-lactamases (ESBL) producing Kpn (ESBL-Kpn) and 125 with non-CRKP or non-ESBL-Kpn (susceptible Kpn, S-Kpn). Absolute number of leukomonocyte (CD45+) in CRKP, ESBL-Kpn and S-Kpn were 280.0 (138.0– 523.0) cells/μL, 354.5 (150.3– 737.3) cells/μL, and 637.0 (245.0– 996.5) cells/μL, respectively. Compared with S-Kpn group, the absolute numbers of leukomonocyte (including T lymphocytes, B lymphocytes and natural killer cells) in patients with CRKP were significantly lower than that in patients with S-Kpn (P