Mandatory Mask-Wearing and Hand Hygiene Associated With Decreased Infectious Diseases Among Patients Undergoing Regular Hemodialysis: A Historical-Control Study.

Background: Infections are the second leading cause of death among patients undergoing hemodialysis. However, preventive measures against infectious diseases are limited and have not been made mandatory for patients. Objective: To investigate the incidence of infectious diseases before and during the coronavirus disease (COVID-19) pandemic. Design: A historical comparative study of a prospective cohort. Setting(s): February 1, 2015 to January 31, 2020 was defined as the period before the mitigative confrontation of the COVID-19 pandemic in China. The period from February 1 to June 29, 2020 was defined as the period of mitigative confrontation of the COVID-19 pandemic in China. Participants: A cohort of patients undergoing hemodialysis whose infectious disease episodes were documented prospectively in the hemodialysis unit of the Third Affiliated Hospital of Guangzhou Medical University since February 1, 2015. Methods: Mandatory mask-wearing and reinforced hand-hygiene education were implemented to prevent COVID-19 from January 23, 2020 in China. The incidence of infectious episodes, including catheter-related infection, digestive tract infection, upper respiratory tract infection (UTRI), pneumonia, and infection at other sites, were documented and compared in the periods before and during the pandemic. Results: The historical control group consisted of 157 patients, with 79 patients in the COVID-19 prevention group. The mask-wearing rate of patients increased from 1.5 to 100%. Hand sanitizer consumption increased significantly during the COVID-19 pandemic. The compliance rates of hand hygiene increased from 66, 75.5, to 55% in physicians, nurses, and other employees before the pandemic to 90.5, 92.5, and 76.5%, respectively. The incidences of UTRI and pneumonia decreased during the pandemic (p < 0.001). Notably, catheter-related and digestive tract infections also decreased during the pandemic (p = 0.003 and 0.034, respectively). A matched-pair study was conducted to further analyze the 79 individual changes in the incidences of infectious disease before and during the pandemic. As a result, the incidences of UTRI, pneumonia, catheter-related infections, digestive tract infections, and infections at other sites all decreased during the pandemic. Conclusions: The present study indicated an association between mandatory mask-wearing and reinforced hand hygiene education and decreased respiratory, catheter-related, and digestive tract infection episodes in the hemodialysis unit.

Expansion of Monocytic Myeloid-Derived Suppressor Cells in Patients Under Hemodialysis Might Lead to Cardiovascular and Cerebrovascular Events.

Background: The specific mechanism of cardiovascular and cerebrovascular vasculopathy in the context of end-stage renal disease has not been elucidated. In the present study, we investigated the clinical impact of myeloid-derived suppressor cells (MDSCs) on hemodialysis patients and their mechanism of action. Methods: MDSCs were tested among 104 patients undergoing hemodialysis and their association with overall survival (OS) and cardiovascular and cerebrovascular events was determined. Results: Hemodialysis patients presented a significantly higher level of monocytic MDSCs (M-MDSCs) compared to healthy controls. M-MDSC were tested 3 months after first testing among 103 hemodialysis patients, with one patient not retested due to early death. The repeated results of M-MDSC levels were consistent with the initial results. Patients with persistent high level of M-MDSCs presented decreased OS, as well as increased stroke and acute heart failure events. As illustrated by multivariate Cox regression, M-MDSC was an independent predictor for OS and stroke events of hemodialysis patients. T cell proliferations were significantly abrogated by hemodialysis-related M-MDSCs in a dose-dependent manner. Besides, M-MDSCs presented higher levels of CXCR4 and VLA-4 compared to monocytes, which indicated their enhanced capability to be recruited to atherosclerotic lesions. The expression of arginase I and activity of arginase was also significantly raised in hemodialysis-related M-MDSCs. Human coronary arterial endothelial cells (HCAECs) presented increased capability to migration by coculture with M-MDSCs, compared with monocyte group. Arginase inhibitor and L-arginine abrogated the immune suppressive function and induction of HCAECs migration of hemodialysis related M-MDSC. Plasma IFN-γ, TNF-α and IL-6 were elevated in hemodialysis patients compared with healthy control. M-MDSC level was positively related to IL-6 level among hemodialysis patients. The plasma of hemodialysis patients induced M-MDSCs significantly compared with plasma from health donors. Besides, IL-6 neutralizing antibody significantly abrogated the induction. Neutralizing antibody of IFN-γ and TNF-α partially decreased the generation of arginase of the induced M-MDSC. Conclusions: M-MDSCs were elevated in ESRD patients under hemodialysis, and they exhibited a strong association with the risk of cardiovascular and cerebrovascular diseases. Hemodialysis related M-MDSC presented enhanced recruitment to atherosclerotic lesions, promoted the migration of endothelial cells through exhaustion of local L-arginine.