Background Chronic kidney disease (CKD) and immunosuppression, such as in renal transplantation (RT), stand as one of the established potential risk factors for severe coronavirus disease 2019 (COVID-19). Case morbidity and mortality rates for any type of infection have always been much higher in CKD, haemodialysis (HD) and RT patients than in the general population. A large study comparing COVID-19 outcome in moderate to advanced CKD (Stages 3–5), HD and RT patients with a control group of patients is still lacking. Methods We conducted a multicentre, retrospective, observational study, involving hospitalized adult patients with COVID-19 from 47 centres in Turkey. Patients with CKD Stages 3–5, chronic HD and RT were compared with patients who had COVID-19 but no kidney disease. Demographics, comorbidities, medications, laboratory tests, COVID-19 treatments and outcome [in-hospital mortality and combined in-hospital outcome mortality or admission to the intensive care unit (ICU)] were compared. Results A total of 1210 patients were included [median age, 61 (quartile 1–quartile 3 48–71) years, female 551 (45.5%)] composed of four groups: control (n = 450), HD (n = 390), RT (n = 81) and CKD (n = 289). The ICU admission rate was 266/1210 (22.0%). A total of 172/1210 (14.2%) patients died. The ICU admission and in-hospital mortality rates in the CKD group [114/289 (39.4%); 95% confidence interval (CI) 33.9–45.2; and 82/289 (28.4%); 95% CI 23.9–34.5)] were significantly higher than the other groups: HD = 99/390 (25.4%; 95% CI 21.3–29.9; P < 0.001) and 63/390 (16.2%; 95% CI 13.0–20.4; P < 0.001); RT = 17/81 (21.0%; 95% CI 13.2–30.8; P = 0.002) and 9/81 (11.1%; 95% CI 5.7–19.5; P = 0.001); and control = 36/450 (8.0%; 95% CI 5.8–10.8; P < 0.001) and 18/450 (4%; 95% CI 2.5–6.2; P < 0.001). Adjusted mortality and adjusted combined outcomes in CKD group and HD groups were significantly higher than the control group [hazard ratio (HR) (95% CI) CKD: 2.88 (1.52–5.44); P = 0.001; 2.44 (1.35–4.40); P = 0.003; HD: 2.32 (1.21–4.46); P = 0.011; 2.25 (1.23–4.12); P = 0.008), respectively], but these were not significantly different in the RT from in the control group [HR (95% CI) 1.89 (0.76–4.72); P = 0.169; 1.87 (0.81–4.28); P = 0.138, respectively]. Conclusions Hospitalized COVID-19 patients with CKDs, including Stages 3–5 CKD, HD and RT, have significantly higher mortality than patients without kidney disease. Stages 3–5 CKD patients have an in-hospital mortality rate as much as HD patients, which may be in part because of similar age and comorbidity burden. We were unable to assess if RT patients were or were not at increased risk for in-hospital mortality because of the relatively small sample size of the RT patients in this study.

Introduction: Removal of uremic toxins is a main objective of hemodialysis; however, whether high-flux and medium cutoff (MCO) membranes differ as regards removal of middle and large uremic toxins is not clear. Objective: To compare medium cutoff and high-flux dialyzers as regards their intra-and interdialysis effect on circulating levels of middle and large uremic toxins and serum albumin. Methods: Fiftytwo patients were randomized to have hemodialysis with either 3 months of high-flux dialyzer followed by 3 months of MCO or vice versa. Blood samples were taken before and after dialysis at the first and last sessions of each dialyzer for analyses of middle and large uremic toxins including inflammatory mediators and vascular endothelial growth factor (VEGF), and serum albumin. Results: Reduction rates were higher, and postdialysis levels of β-2 microglobulin, free kap-pa and lambda light chains, and myoglobulin were lower at the first and last sessions with MCO dialyzers compared to high-flux dialyzers (p < 0.05 for all). Last session predialysis levels of β-2 microglobulin, free kappa light chain, and free lambda light chain were lower than first session predialysis levels in MCO dialyzers as compared to high-flux dialyzers (p < 0.05 for all). Last session levels of interleukin-6, interleukin-10, interleukin-17, and interferon-gamma did not differ between dialyzers (p > 0.05 for all). VEGF level was lower in the MCO group compared to the high-flux group (p = 0.043). Last session level of serum albumin with MCO dialyzers was lower than that with high-flux dialyzers (3.62 [3.45-3.88] vs. 3.78 [3.58-4.02] g/L) (p = 0.04) and 6.7% lower (p < 0.001) than at the first session of MCO dialyzers. Conclusion: The decline in circulating levels of several middle and large uremic toxins including VEGF following hemodialysis was more pronounced when using MCO membranes as compared to high-flux membranes while their effect on inflammatory molecules was similar.

Coronavirus disease 19 (COVID-19) became a nightmare for the world since December 2019. Although the disease affects people at any age; elderly patients and those with comorbidities were more affected. Everyday nephrologists see patients with hypertension, chronic kidney disease, maintenance dialysis treatment or kidney transplant who are also high-risk groups for the COVID-19. Beyond that, COVID-19 or severe acute respiratory syndrome (SARS) due to infection may directly affect kidney functions. This broad spectrum of COVID-19 influence on kidney patients and kidney functions obviously necessitate an up to date management policy for nephrological care. This review overviews and purifies recently published literature in a question to answer format for the practicing nephrologists that will often encounter COVID-19 and kidney related cases during the pandemic times.

Attaining and maintaining optimal “dry weight” is one of the principal goals during maintenance hemodialysis (MHD). Recent studies have shown a close relationship between Na+ load and serum vascular endothelial growth factor-C (VEGF-C) levels; thus, we aimed to investigate the role of VEGF-C as a candidate biomarker of hypervolemia. Physical examination, basic laboratory tests, N-terminal pro b-type natriuretic peptide (NT-ProBNP), echocardiography, and bioimpedance spectroscopy data of 3 groups of study subjects (euvolemic MHD patients, healthy controls, and hypervolemic chronic kidney disease [CKD] patients) were analyzed. Research data for MHD patients were obtained both before the first and after the last hemodialysis (HD) sessions of the week. Data of 10 subjects from each study groups were included in the analysis. Serum VEGF-C levels were significantly higher in hypervolemic CKD versus in MHD patients both before the first and after the last HD sessions (P = .004 and P = .000, respectively). Healthy controls had serum VEGF-C levels similar to and higher than MHD patients before the first and after the last HD sessions of the week (P = .327 and P = .021, respectively). VEGF-C levels were correlated with bioimpedance spectroscopy results (r2 0.659, P = .000) and edema (r2 0.494, P =0.006), but not with ejection fraction (EF) (r2 −0.251, P = .134), blood pressures (systolic r2 0.037, P = 0.824, diastolic r2 −0.067, P = .691), and NT-ProBNP (r2 −0.047, P = .773). These findings suggest that serum VEGF-C levels could be a potential new biomarker of hypervolemia. The lack of correlation between VEGF-C and EF may hold a promise to eliminate this common confounder. Further studies are needed to define the clinical utility of VEGF-C in volume management.

Sarcopenia or muscle wasting is a progressive and generalized skeletal muscle disorder involving the accelerated loss of muscle mass and function, often associated with muscle weakness (dynapenia) and frailty. Whereas primary sarcopenia is related to ageing, secondary sarcopenia happens independent of age in the context of chronic disease states such as chronic kidney disease (CKD). Sarcopenia has become a major focus of research and public policy debate due to its impact on patient's health‐related quality of life, health‐care expenditure, morbidity, and mortality. The development of sarcopenia in patients with CKD is multifactorial and it may occur independently of weight loss or cachexia including under obese sarcopenia. Hormonal imbalances can facilitate the development of sarcopenia in the general population and is a common finding in CKD. Hormones that may influence the development of sarcopenia are testosterone, growth hormone, insulin, thyroid hormones, and vitamin D. Although the relationship between free testosterone level that is low in uraemic patients and sarcopenia in CKD is not well‐defined, functional improvement may be seen. Unlike testosterone, it is known that vitamin D is associated with muscle strength, muscle size, and physical performance in patients with CKD. Outcomes after vitamin D replacement therapy are still controversial. The half‐life of growth hormone (GH) is prolonged in patients with CKD. Besides, IGF‐1 levels are normal in patients with Stage 4 CKD—a minimal reduction is seen in the end‐stage renal disease. Unresponsiveness or resistance of IGF‐1 and changes in the GH/IGF‐1 axis are the main causes of sarcopenia in CKD. Low serum T3 level is frequent in CKD, but the net effect on sarcopenia is not well‐studied. CKD patients develop insulin resistance (IR) from the earliest period even before GFR decline begins. IR reduces glucose utilization as an energy source by hepatic gluconeogenesis, decreasing muscle glucose uptake, impairing intracellular glucose metabolism. This cascade results in muscle protein breakdown. IR and sarcopenia might also be a new pathway for targeting. Ghrelin, oestrogen, cortisol, and dehydroepiandrosterone may be other players in the setting of sarcopenia. In this review, we mainly examine the effects of hormonal changes on the occurrence of sarcopenia in patients with CKD via the available data.