Volume 103 ·  Issue 08 ·  2023

Compared with traditional low-molecular-weight heparin anticoagulation or non-anticoagulant hemodialysis, regional citrate anticoagulation (RCA) has emerged as a promising anticoagulant method considering its satisfactory efficacy, reduced incidence of bleeding, extended life of the dialyzer and increased removal of the toxin. RCA has received more and more attention in recent years which contributes as a first-line anticoagulant regimen for continuous renal replacement therapy, and it gradually gains wide clinical application in maintenance hemodialysis (MHD). In addition, RCA has been reported to be successfully used in plasma exchange and hemoperfusion. This article elaborates on mechanism of RCA and the problems in clinical application, in order to further expand the application of RCA and improve the effect of blood purification in the future.

SARS-CoV-2 has been mutating ever since COVID-19 became a global pandemic in 2020, resulting in changes in its viral characteristics. Dealing with infections due to the Omicron variant, it is important for healthcare facilities to dynamically carry out accurate and scientific prevention and control strategies. The current consensus aimed to target the most concerned aspects, including the detection, transmission, prevention and disinfection of the Omicron variant. Through reviewing the latest evidence-based literature, rounds of discussions, and multiple revisions, the panel of experts formed 22 evidence-based recommendations. This consensus provides scientific and practical guidance for the medical institutions, as well as providing reference for other professional organizations and personnel.

To explore the effect of hemoperfusion (HP) combined with hemodialysis (HD) (HD+HP) on protein energy wasting (PEW) and long-term prognosis in patients on maintenance HD (MHD).

A prospective multicenter cohort study was conducted. Adult MHD patients who completed PEW assessment and underwent regular dialysis between July 2015 and July 2021 at 23 hemodialysis centers in Guizhou Province were selected. Demographic characteristics, physical indicators, laboratory indicators, 3-day diet diary and HP treatment data of the subjects were collected. The patients were divided into different groups according to the presence or absence of HP, the frequency of HP treatment and the type of cartridge, and then relevant indicators were compared. Multivariate logistic regression model and Cox proportional regression model were used to analyze the influence of HP treatment on PEW risk in MHD patients. Meanwhile, Kaplan-Meier method was used to plot the survival curve.

A total of 4 623 MHD patients (2 789 males and 1 834 females) aged (53.7±15.9) years were included in the study, with a median dialysis age of 64.3 (44.3, 92.3) months. There were 3 429 (74.2%) MHD patients treated with HD+HP, and 1 194 patients (25.8%) were not treated with HP. According to the 2008 diagnostic criteria of the International Society for Renal Nutrition and Metabolism (ISRNM), the incidence of PEW was 26.0% (1 204/4 623). Multivariate logistic regression analysis showed that female (OR=2.48, 95%CI: 1.55-3.95, P<0.001), diabetes (OR=1.75, 95%CI: 1.08-2.83, P=0.024) and high-sensitivity C-reactive protein (hs-CRP) (OR=1.02, 95%CI: 1.01-1.03, P=0.003) were risk factors for PEW, while treatment with HD+HP (OR=0.51, 95%CI: 0.31-0.87, P=0.012) and elevated triglyceride levels (OR=0.62, 95%CI: 0.48-0.80, P<0.001) were protective factors. Cox hazard ratio regression showed that among different HP treatment frequencies and cartridge types, 2 times/month (HR=0.40, 95%CI: 0.17-0.95, P=0.037), 3 times/month (HR=0.44, 95%CI: 0.23-0.85, P=0.014), 4 times/month (HR=0.54, 95%CI: 0.34-0.85, P=0.008), HA130 (HR=0.57, 95%CI: 0.36-0.89, P=0.014) and HA230 (HR=0.30, 95%CI: 0.15-0.63, P=0.001) had protective effects on the occurrence of PEW in MHD patients. The all-cause mortality rate was 11.3% (521/4 623) at 33 (24, 48) months of follow-up. Kaplan-Meier analysis showed that patients undergoing 4 times/month HP treatment (χ²=36.78, P<0.001) and using HA230 (χ²=9.46, P=0.002) had the highest survival rate.

Treatment with HD+HP is a protective factor for PEW in patients with MHD, and 4 times/month HP treatment or HA230 significantly reduces the risk of PEW and all-cause mortality in patients with MHD.

To explore the correlation between fluid load index and cardiovascular events in hemodialysis patients based on repeated body composition analyses.

A prospective cohort study was conducted to collect the clinical data of patients undergoing maintenance hemodialysis (MHD) in the Department of Nephrology, Hangzhou Hospital of Traditional Chinese Medicine from July to September 2020. The pre-dialysis fluid overload (FO) index-overhydration (OH) was measured by bioelectrical impedance method, and the follow-up monitoring was conducted every 6 months. According to the baseline OH value, patients were divided into non-FO group (OH≤2.5 L) and FO group (OH>2.5 L). Moreover, according to the repeated measurements, the patients were divided into continuous non-FO group, continuous FO group and intermittent FO group. All patients were followed up until October 1, 2022, and the outcomes were recorded. The end point of follow-up was cardiovascular events. The cumulative incidence of cardiovascular events was calculated by the Kaplan-Meier method, and the risk factors of cardiovascular events were analyzed by Cox proportional hazards regression model.

A total of 289 patients were included, including 88 patients (30.4%) with FO and 201 patients (69.6%) with non-FO. There were 168 males (58.1%) and 121 (41.9%) females, with an average age of (58±13) years and an average follow-up time of (22.0±6.5) months. Kaplan-Meier analysis showed that the incidence of cardiovascular events in the baseline FO group was higher than that in the non-FO group (log-rank χ²=14.44, P<0.001). The incidence of cardiovascular events in both the continuous FO group and the intermittent FO group was higher than that in the continuous non-FO group (log-rank χ²=41.47, P<0.001; log-rank χ²=18.36, P<0.001). After adjustment for gender, age, comorbidities, and biochemical indicators, the incidence of cardiovascular events in the baseline FO group was 1.850 times of the non-FO group (95%CI: 1.046-3.271, P=0.034). The incidence of cardiovascular events in the continuous FO group was 4.679 times of the continuous non-FO group (95%CI: 2.189-10.002, P<0.001). The incidence of cardiovascular events in the intermittent FO group was 3.410 times of the continuous non-FO group (95%CI: 1.696-6.857, P=0.001).

OH value measured by bioelectrical impedance can be used as an important reference index for clinical monitoring of cardiovascular events in MHD patients. Continuous chronic and intermittent exposures to FO are risk factors for cardiovascular events in hemodialysis patients.

To explore the correlation between polycyclic aromatic hydrocarbons (PAHs) component phenanthrene and clinical indicators in patients on continuous ambulatory peritoneal dialysis (CAPD).

A total of 22 patients who underwent peritoneal dialysis catheterization and regular dialysis in the First Affiliated Hospital of Zhengzhou University from June to August 2018 were selected. Meanwhile, 18 healthy adults who underwent physical examination were also selected as the control group. Fasting blood samples were taken to detect the concentration of PAHs components for comparison, and the correlation between PAHs components and clinical indicators was further analyzed.

There were 22 cases in CAPD group (13 males and 9 females), and aged (45±13) years, while there were 18 cases in control group (6 males and 12 females), and aged (41±13) years. The concentration of blood phenanthrene (PHE) was the highest in CAPD group [0.449 (0.254, 0.581) mg/L], and it was only lower than acenaphthene in the control group [0.081 (0.050, 0.444) mg/L], with a statistically significant difference between the two groups (P=0.008). The analysis of PHE and clinical indicators showed that the concentration of PHE in CAPD patients was negatively correlated with weekly urea clearance index (Kt/V), weekly creatinine clearance (Ccr) and leukocyte level, but positively correlated with triglyceride level (r=-0.743, -0.749, -0.655 and 0.610, respectively, all P<0.05). Simple linear regression analysis demonstrated that for every 0.1 mg/L increase in PHE concentration, weekly Kt/V, weekly Ccr and white blood cell count decreased by 0.226, 3.050 L/1.73 m² and 0.512×10⁹/L, respectively, but triglyceride level increased by 0.152 mmol/L (all P<0.05). Multiple linear regression analysis revealed that the blood PHE concentration of CAPD patients was negatively correlated with weekly Kt/V and Ccr levels (t=-2.402 and -2.368, respectively, both P<0.05). All CAPD patients were followed up for 3 years, during which 8 patients (36.4%) withdrew from peritoneal dialysis due to technical failure, and the baseline PHE concentration was higher than that of patients who did not quit peritoneal dialysis [0.572 (0.416, 0.662) vs 0.268 (0.120, 0.475) mg/L, P=0.003]. Eight patients (36.4%) had cardiovascular events, and the baseline blood PHE concentration was higher than that of patients without cardiovascular events [0.542 (0.389, 0.741) vs 0.373 (0.157, 0.545) mg/L, P=0.045].

PHE correlates with clinical indicators of CAPD patients, including Kt/v, Ccr, leukocyte and triglyceride.

To investigate the knowledge, use and barriers when prescribing GLP-1RA and SGLT2i among cardiologists, endocrinologists and general practitioners, and explore the influencing factors that hinder the use of these medications.

A questionnaire was conducted among physicians in the above departments in Peking University Third Hospital and health service institutions at all levels in its medical consortium. A total of 342 physicians were involved. Among them, 40.6% (139) were cardiologists, 28.9% (99) were endocrinologists and 30.4% (104) were general practitioners; 66.7% (270) came from Beijing while 33.3% (72) from other provinces. The survey included clinicians′ knowledge and current use of GLP-1RA and SGLT2i, and the possible reasons that influenced the prescription of these medications. Medical therapies of physicians were investigated by simulating different clinical scenarios. The difference of measures among physicians in different departments was compared.

A total of 342 physicians were involved, with the average age of 40 (35, 46) years old and the average working time of 13 (7, 20) years. Among them, 40.6% (139) were male. 77.5% (265) physicians had comprehensive knowledge of SGLT2i and prescribed it, which was higher than that for GLP-1RA (70.5%, 241) (P<0.001). 21.1% (72) physicians prescribed SGLT2i more than 20 times per month, which was higher than that for GLP-1RA (8.2%, 28) (P<0.001). Endocrinologists had more knowledge and prescribed more GLP-1RA and SGLT2i compared with other physicians (both P values<0.001). 38.1% (53) cardiologists, 22.2% (22) endocrinologists, and 30.8% (32) general practitioners believed patients needed an endocrinologist to evaluate and adjust GLP-1RA, which was the primary barrier for the use of medications (P=0.042). 27.4% (38) cardiologists, 14.1% (14) endocrinologists, and 30.8% (32) general practitioners believed patients needed an endocrinologist to evaluate and adjust SGLT2i, which was the primary barrier for the use of medications (P=0.018). 21.6% (30) cardiologists, 45.5% (45) endocrinologists, and 31.7% (33) general practitioners believed side effects of SGLT2i was the primary barrier for the use of medications (P<0.001). For patients with unqualified glycemic control and cardiovascular complications, 65.4% (75) cardiologists, 69.7% (69) endocrinologists, and 43.3% (45) general practitioners chose the above medications (P<0.001). For patients with qualified glycemic control, combined with cardiovascular complications and diabetic organ damage, 35.3% (49) cardiologists, 52.5% (52) endocrinologists, and 25.0% (26) general practitioners chose the above medications (P<0.001).

Physicians had more knowledge and prescription of SGLT2i than that of GLP-1RA. Endocrinologists had more knowledge and prescription of the above medications than other physicians. The side effect of medications was potential primary barrier for the use of the novel hypoglycemic agent with cardiovascular benefits. In clinical practice, most of physicians considered that high-risk patients with cardiovascular comorbidities need to be referred to cardiologist or endocrinologist to adjust clinical therapies.

To investigate the associations of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene polymorphism and plasma soluble TRAIL level (sTRAIL) with Crohn′s disease (CD) and to retrospectively analyze the effects of TRAIL gene variants and plasma sTRAIL levels on clinical response to infliximab (IFX).

From January 2012 to January 2021, 312 CD patients [205 males, 107 females, average age (33.9±9.8) years] and 514 age-and gender-matched healthy controls [304 males, 210 females, average age (34.9±9.4) years] were recruited from the Department of Gastroenterology, the Second Affiliated Hospital of Wenzhou Medical University. Among them, 72 patients with active CD who were ineffective or intolerant to traditional drug therapy regularly received IFX (5 mg/kg) treatment. According to the changes in the Harvey-Bradshaw index (HBI) and the Simplified Endoscopic Score for Crohn′s Disease (SES-CD) in the 14^th week, these patients were classified into response group (a decrease in HBI≥3 or a decrease in SES-CD≥50%) and non-response group. TRAIL (rs1131568) gene polymorphism was analyzed by matrix-assisted laser desorption/ionization time of flight mass spectrometry technique. The plasma sTRAIL level was examined by enzyme-linked immunosorbent assay (ELISA). Based on the Montreal CD classification criteria, all CD patients were divided into different subgroups. Finally, a comprehensive analysis was performed to investigate the relationship between TRAIL (rs1131568) gene polymorphism, the plasma sTRAIL level and the risk of CD, the clinicopathological characteristics of CD patients, and the clinical response to IFX.

The recessive model analysis showed that the homozygous variant genotype (CC) was more prevalent in patients with moderately to severely active CD than in those with mildly active CD (45.34% vs 29.23%, P=0.005). Both variant allele (C) and homozygous variant genotype (CC) in patients with stricturing and penetrating CD were more frequent than those in patients with non-stricturing and non-penetrating CD (65.48% vs 57.53%, P=0.046; 49.21% vs 31.18%, P=0.001). The dominant model analysis showed that variant allele (C) and variant genotype (TC+CC) was higher in CD patients with perianal lesions than in those without perianal lesions (66.83% vs 58.17%, P=0.037; 92.31% vs 78.37%, P=0.002). The average plasma sTRAIL level was higher in CD patients than in healthy controls [(243.04±42.74) ng/L vs (194.16±31.14) ng/L, P<0.001]. Compared with the patients with mildly active CD, the plasma sTRAIL level was increased in those with moderately to severely active CD [263.47(242.09, 281.91) ng/L vs 231.13(211.11, 247.11) ng/L, P<0.001]. The same conclusion was also drawn for the patients with stricturing and penetrating CD in contrast to those with non-stricturing and non-penetrating CD [266.18 (246.68, 289.91) ng/L vs 227.19 (204.57, 249.59) ng/L, P<0.001]. The plasma sTRAIL level was also higher in patients with perianal disease than in those without perianal disease [(261.40±41.51) ng/L vs (233.86±40.41) ng/L, P<0.001]. Multiple linear regression analysis further showed that disease activity (β=22.640, P<0.001) and homozygous variant genotype (CC) (β=16.814, P<0.001) may be positively related to the plasma sTRAIL level in CD patients independently. At the 14^th week of IFX treatment, the plasma sTRAIL level in the response group was lower than that in the non-response group [205.98(190.72, 214.56) ng/L vs (238.33±29.38) ng/L, P<0.001]. Compared with week 0, the plasma sTRAIL level was decreased in the response group in the 14^th week [(205.98 (190.72, 214.56) ng/L vs (239.89±42.43) ng/L, P<0.001]. Non-conditional logistic regression analysis showed that variant allele (C) and variant genotype (TC+CC) were less frequent in the response group than in the non-response group (53.33% vs 70.83%, P=0.037; 70.00% vs 91.67%, P=0.036).

The increased plasma sTRAIL level may be a risk factor for CD. TRAIL (rs1131568) gene variation and the increase of plasma sTRAIL level may be associated with the increased disease activity of CD and may be the risk factors for stenosis, penetration, and perianal lesions in CD patients. In addition, TRAIL (rs1131568) gene variation or the increase of plasma sTRAIL level may be related to no response to IFX treatment in CD patients.

A total of 20 patients (8 males and 12 females) aged (64.8±13.9) years who underwent regular hemodialysis and had bone loss or osteoporosis in Peking University People′s Hospital from July to December 2021 were recruited. Sixty milligrams of denosumab were given subcutaneously. The average serum calcium decreased by 0.31 mmol/L and 40% (8/20) of the patients had hypocalcemia one month after treatment. The markers of bone turnover began to decrease 3 days after treatment, and continued to decrease until 5 months after denosumab medication. Multivariate logistic regression analysis failed to detect any independent risk factor for hypocalcemia (R²=0.516, P=0.021). Therefore, denosumab can significantly inhibit bone turnover in hemodialysis patients, however, patients with denosumab medication are more prone to hypocalcemia.

A total of 36 patients with suspected peritoneal dialysis (PD) catheter dysfunction in the First Hospital of China Medical University from June 2020 to August 2022 were included, and five patients with normal PD catheter were also included as the control group. There were 22 males and 19 females, and aged (45±21) years. The volume of rapid-phase drainage in the control and dysfunction groups was (2 086±65) and (1 181±637) ml, and the total drainage time was (15.2±1.3) and (38.3±14.9) min, respectively. The volume of rapid-phase drainage in the dysfunction group was reduced and the total drainage time was longer than that in the control group (both P<0.05). Compared with group with PD catheter migration, the duration of new bag instillation was prolonged, the drainage volume in the rapid-phase was reduced, the total drainage duration was prolonged, and the ultrafiltration volume was decreased in the group with PD catheter obstruction (all P<0.05). The rapid exchange test can provide an early preliminary diagnosis of PD catheter dysfunction and identify the type of catheter dysfunction.

This article reports a patient with cystic-solid space occupying in the hepatic hilar area. Imaging examination showed irregular mass shadow in the hepatic hilar region, and multilocular cystic changes were seen inside. The cystic wall and septum were mild and delayed on enhanced scan, and the cystic part was not clearly enhanced. Enlarged lymph nodes were seen retroperitoneally, which was considered a malignant tumor. However, the clinical manifestations and laboratory examinations were unclear. Further laboratory examination and puncture biopsy confirmed that he was rare liver tuberculosis, and he recovered after regular anti-tuberculosis treatment. The current clinical diagnosis and treatment is reported as follows.

The clinical manifestations, biochemical tests, imaging data and the clinical manifestations of the parents of a 29-year-old patient were reported to analyze the pathogenic genes and clinical characteristics of fibroblast growth factor receptor 1 (FGFR1) gene inactivation mutation leading to Kalman syndrome (KS) in patients with KS, so as to increase the understanding of the pathogenesis of this disease. Peripheral venous blood of patients and their parents was extracted, genomic DNA was extracted, and mRNA of blood of patients and fathers was extracted at the same time, and then reverse transcription into cDNA was performed for second generation sequencing. The reasons why the patient differs from the father's phenotype were analyzed. The results showed that (1) according to the clinical manifestations of the patients and the laboratory examination results of the decrease of gonadotropin and testosterone levels, the diagnosis of KS was confirmed, and the parents of the patients were normal; (2) There is a splice site mutation in the patient's FGFR1 (c.359-1G>A). The mutation comes from the father, but the father's gonadal axis functions normally, and the mutation is the first reported; (3) The patient's FGFR1 transcript is missing exon 4, while the patient's father's FGFR1 transcript is normal; (4) Gonadotropin-releasing hormone (GnRHa) pulse therapy is effective, and sperm is produced after medication. In conclusion, FGFR1 gene splice site mutation leads to KS, which is rarely reported in the literature. The diagnosis and treatment process is reported as follows.

Protein energy expenditure is prevalent in maintenance hemodialysis patients and is strongly associated with poor clinical prognosis. The direct induction of bone mineral metabolism disorder in chronic kidney disease and the abnormal neurohumoral function of hypothalamic energy center promote the enhancement of protein catabolism and skeletal muscle consumption, and accelerate the occurrence and development of protein energy consumption. Therefore, regular nutritional system evaluation by anthropometric and component analysis, biochemical index monitoring and other methods, optimizing nutritional intake and renal replacement therapy programs, increasing protein synthesis hormones, reducing inflammatory factor levels, improving appetite, and moderate exercise and rehabilitation treatment are comprehensive management strategies for protein energy consumption.

The concept of blood purification began in the hemodialysis of uremic patients, and has developed beyond the scope of hemodialysis until now. It includes not only various hemodialysis and peritoneal dialysis technologies for renal replacement therapy for the purpose of removing small molecule toxins, but also special blood purification treatment methods for removing medium and macromolecular substances. In particular, the latter has developed rapidly in recent years and has achieved good results in the treatment of multidisciplinary diseases. This article reviews the application of special blood purification treatment methods in various clinical fields such as rare diseases, critical diseases and tumor diseases.

Sepsis-related acute kidney injury (SA-AKI) is the leading cause of acute kidney injury in intensive care units (ICU), accounting for more than 50%, and is associated with prolonged hospital stay, progression to chronic kidney disease, and high mortality, of which 15% ~20% require renal replacement therapy (RRT). In recent years, extracorporeal blood purification has made some progress as the main treatment for SA-AKI in ICU. In addition to the traditional continuous RRT (CRRT) method, blood purification technology has also developed adsorption membranes specific for endotoxin and cytokines, blood perfusion columns, etc., mainly including various in vitro blood purification modes such as high retention filter, hemoperfusion/blood adsorption, high adsorption hemofiltration and continuous plasma filtration adsorption, aiming to improve the prognosis of patients by reducing the levels of endotoxin and cytokines in the blood circulation of SA-AKI patients. This article focuses on the above-mentioned blood purification mode for the treatment of SA-AKI, which provides reference for clinical treatment decision-making.

Bronchiectasis (bronchiectasis for short) is a chronic respiratory disease with cough, expectoration, and/or hemoptysis as the main clinical manifestations. Its radiological manifestation is abnormal permanent dilatation of the bronchus with or without thickening of the bronchial wall. Treatment goals include: reducing symptoms, improving quality of life, protecting lung function, and reducing overall morbidity and mortality. This article briefly summarizes some new developments in the field of bronchial expansion from the end of 2021 to November 2022, mainly including pathophysiology, diagnosis, treatment, comorbidities, etc., and looks forward to providing ideas for future research directions of bronchial expansion.

Organoids and assembloids, as micro-organs with three-dimensional structures, can highly simulate the morphological structure and physiological function of the source tissues, and cultivate tissue structures with stable phenotypes. They are good models for clinical disease research. The research on organoids and assembled assemblies is progressing rapidly and has broad application prospects. It is of great significance in the research of physiology, organ transplantation, biological signaling, drug development, high-throughput screening and individualized tumor treatment. This paper briefly reviews the research progress of organoid and assembly-like models in colorectal malignant tumors, discusses the generation and development process of organoid and assembly-like models, summarizes the existing organoid and assembly-like culture technologies and their application scenarios, especially the progress in the research and drug screening of colorectal malignant tumors. These research results show that organoids and assembly-like models, as a novel and reliable clinical model in the study of colorectal malignant tumors, have outstanding advantages in high-throughput drug screening, and can be combined with liquid biopsy, gene editing, tumor immunotherapy and other technologies in many research fields.

Hemodialysis centers typically provide maintenance hemodialysis to all patients using standard dialysate temperatures (e.g., 36.5 °C), whereas it is unknown whether the use of cryogenic dialysate (e.g., 36.0 °C or lower) reduces the risk of cardiovascular-related death or hospitalization. The study was a pragmatic, two-arm, parallel, registered, open-label, cluster-randomized superiority trial (MyTEMP) conducted at a hemodialysis centre in Ontario, Canada. The study included 84 hemodialysis centers that could provide specific interventions, each providing maintenance hemodialysis treatment to at least 15 patients per week. Eighty-four centers were divided into two groups using covariate-constrained randomization, one group (42 centers) using personalized cooler dialysate (the nurse set the dialysate temperature 0.5 to 0.9 °C below each patient's pre-dialysis measured body temperature, and the recommended minimum dialysate temperature is 35.5 °C), and the other group (42 centers) using standard temperature dialysate (both 36.5 °C). During the 4-year trial, the primary endpoint event was cardiovascular-related death or hospital admission due to myocardial infarction, ischemic stroke, or congestive heart failure, recorded in the provincial database by medical coders who were not aware of the trial or center assignment. Approximately 4.3 million outpatient maintenance hemodialysis treatments were provided to 15 413 patients during the 4-year trial. The mean dialysate temperature was 35.8 ℃ in the cryogenic dialysate group and 36.4 ℃ in the standard temperature group. Primary endpoint events occurred in 1 711 (21.4%) of 8 000 patients in the hypothermia dialysis group and 1 658 (22.4%) of 7 413 patients in the standard temperature group (HR=1.00，96%CI：0.89~1.11，P=0.93）。 Mean systolic blood pressure decreased by 26.6 mmHg in the cryogenic dialysate group and 27.1 mmHg in the standard temperature group (mean difference-0.5 mmHg, 99%CI：-1.4~0.4，P=0.14）。 It was concluded that the personalized cryogenic dialysate provided at the hemodialysis center did not significantly reduce the risk of major cardiovascular events compared to the standard temperature dialysate. The study raises questions about the growing popularity of cryogenic dialysate, and the risks and benefits of cryogenic dialysate in specific patient populations should be further clarified in future trials.

During the novel coronavirus pneumonia (COVID-19) pandemic, maintenance hemodialysis (MHD) patients were limited to receive hemodialysis treatment across regions due to their high comorbidities, making them a highly vulnerable group. Therefore, it is necessary to understand the risk factors for developing COVID-19 in patients with MHD and their prognosis. Dialysis Clinic, Inc. (DCI) is a non-profit dialysis provider in the United States with approximately 260 dialysis centers in 29 states with 15,000 MHD patients. The study retrospectively analyzed the demographic profile, dialysis characteristics, residential environment, comorbidity situation, frailty (using a wheelchair or requiring assistance), and substance use of patients receiving hemodialysis treatment at DCI from February to June 2020. The results showed that 438 (5.5%) of the 7,948 MHD patients included in the study were infected with SARS-CoV-2. Among them, men, blacks, central dialysis (compared to home dialysis), treatment in urban clinics, living in agglomerated environments and more comorbidities are associated with infection with SARS-CoV-2. Patients living in clustered settings had a 17-fold risk of developing COVID-19 than those living in non-clustered settings (OR=17.10，95%CI：13.51~21.54）。 Of the 438 MHD patients who developed COVID-19, 109 (24.9%) died. Older age, heart disease and frailty were associated with mortality. It is concluded that COVID-19 is at a higher risk of occurrence in patients undergoing MHD, especially those living in aggregated settings, and that MHD patients have a high mortality rate after developing COVID-19.