Introduction: Kidney transplantation is the treatment of choice for patients with renal failure. It is crucial to select which patients may benefit from renal transplantation and which are at high risk for post-transplant complications. Sarcopenia is associated with poor outcome in various conditions, including in chronic kidney disease patients. The gold standard for measuring sarcopenia is computed tomography (CT) imaging to estimate muscle mass and quality since it is objective, reproducible, and reflects the overall health condition. The data regarding those measurements among kidney transplant recipients are limited, therefore we aimed to describe it in patients before kidney transplantation, assess the parameters associated with sarcopenia, and evaluate the clinical significance of those markers on outcomes following transplantation. Methods: We retrospectively analyzed 183 kidney transplant recipients who had a CT scan 90 days prior to transplant. Sarcopenia was assessed by measuring the cross-sectional area (CSA) and mean muscle density of the psoas muscle at the third and fourth lumbar vertebrae levels and paravertebral muscles at the 12th thoracic vertebra level. Results: There was a strong linear correlation between muscle size measured as CSA of the psoas muscle at the L3 and L4 vertebral body level and the CSA of the paravertebral muscles at the D12 vertebra level, and a moderate correlation to muscle density at those levels. Age was independently associated with risk of sarcopenia, defined as psoas CSA in the lowest tertile, with every year of age increasing the risk by 5%. CSA at the L3 level had a significant independent association with post kidney transplantation mortality, with an adjusted hazard ratio of 0.86 per cm2. There was a significantly longer hospitalization period postoperation in kidney recipients in the lower tertile of psoas CSA and density. Conclusions: Sarcopenia as measured by psoas CSA is associated with poor short- and long-term outcomes following kidney transplantation and should be included as part of the assessment of kidney transplantation candidates.

Introduction: Coronavirus disease is associated with increased morbidity and mortality in maintenance hemodialysis (MHD) patients. Recent breakthrough infection in vaccinated people has led some authorities to recommend a booster dose for patients fully vaccinated 5–8 months ago. We aimed to assess the humoral response of MHD patients following a booster dose with the BNT162b2 vaccine. Methods: The study included 102 MHD patients vaccinated with 2 doses of the BNT162b2 (Pfizer-BioNTech) vaccine. A third dose (booster) was recommended to all MHD patients in our center and was given to those who opted to receive it, resulting in a booster group and a control group that did not receive the booster. Previous exposure was excluded by testing for the presence of the anti-nucleocapsid antibody (SARS-CoV-2) or positive PCR. We assessed the humoral response before and after the booster dose. Results: Of 66 patients in the booster group, 65 patients (98.5%) developed a positive antibody response, from 472.7 ± 749.5 to 16,336.8 ± 15,397.3, as compared to a sustained decrease in the control group (695.7 ± 642.7 to 383.6 ± 298.6), p < 0.0001. No significant adverse effects were reported. Prior antibody titers were positively correlated to IgG levels following the booster dose. There was a significant association between malnutrition-inflammation markers and the humoral response. Conclusions: Almost all MHD patients developed a substantial humoral response following the booster dose, which was significantly higher than levels reported for MHD patients following administration of 2 doses alone. Further studies and observations are needed to determine the exact timing and dosing schedule.

The optimal SARS-CoV-2 vaccination schedule in dialysis patients and the potential need for a fourth vaccine dose are debatable. We prospectively assessed the humoral responses to three and four doses of BNT162b2 among dialysis patients. The study included 106 dialysis patients; 60 (56.6%) and 46 (43.4%) received 3 and 4 vaccine doses, respectively. Anti-spike (anti-S) antibody titers significantly increased after the third vaccine dose, followed by a decline, yet still remained higher than all previous measurements. The fourth vaccine dose led to another profound rise in anti-S titers. The absolute increase following the fourth dose correlated with response to the third dose. Infection risk however was similar between patients vaccinated with three or four doses.

Introduction Breakthrough COVID-19 may occur in vaccinated people, and may result from declining vaccine effectiveness or highly transmittable SARS-CoV-2 variants, such as the B.167.2 (delta) variant. We investigated risk factors and outcomes for infection with the delta variant among vaccinated hemodialysis patients. Methods Patients on maintenance hemodialysis who received two doses of the BNT162b2 (Pfizer-BioNTech) vaccine were analysed according to having developed COVID-19 (study group) or not (control group), in a retrospective, observational, comparative study. We compared risk-factors for developing breakthrough COVID-19 and assessed clinical outcomes, including 30-day mortality rates. Results Twenty-four cases of breakthrough SARS-CoV-2 infection were compared to 91 controls without infection. Breakthrough infection was associated with chronic immunosuppressive treatment, hematological malignancies, and low antibody levels against SARS-CoV-2 spike protein. All COVID-19 cases occurred at least 5 months after vaccination, and most were caused by the B.1.617.2 variant (at least 23/24 cases). COVID-19 was categorized as severe or critical disease in 11/24 patients (46%), and 54% required hospitalization and COVID-19-directed treatment. The source of infection was nosocomial in 6/24 cases (25%), and healthcare-related in 3/24 (12.5%). Mortality rate was 21%. Overall mortality was significantly higher in patients who developed COVID-19 than in controls (odds ratio for all-cause mortality 7.6, 95% CI 1.4–41, p = 0.002). Conclusions Breakthrough COVID-19 with the B.1.617.2 variant can occur in vaccinated hemodialysis patients and is associated with immunosuppression and weaker humoral response to vaccination. Infections may be nosocomial and result in significant morbidity and mortality. Graphical abstract

Background: Patients with end-stage renal disease (ESRD) undergoing chronic hemodialysis are at high mortality and cardiovascular risk. This study was aimed to assess whether the CHA₂DS₂-VASc score may be used for risk stratification of this population. Methods: Included were patients undergoing chronic hemodialysis at Meir Medical Center. The CHA₂DS₂-VASc score was calculated for each patient at the initiation of hemodialysis. Patients were classified into 3 groups according to the CHA₂DS₂-VASc score: 0–3 (low), 4–5 (intermediate), and ≥6 (high). The primary endpoint was the composite of all-cause mortality, myocardial infarction, and stroke during the first year of hemodialysis. Results: Of the 457 patients with ESRD, 181 (40%) had low, 193 (42%) intermediate, and 83 (18%) high CHA₂DS₂-VASc scores. During the first year of hemodialysis, 109 (23.8%) patients died, 17 (3.7%) had a stroke, and 28 (6.1%) had a myocardial infarction. Compared to patients in the low CHA₂DS₂-VASc score group, those in the intermediate and high score groups had higher risk for the composite endpoint (OR: 2.6, 95% CI: 1.6–4.2, p < 0.01 and OR: 4.2, 95% CI: 2.3–7.5, p < 0.01, respectively). Each 1-point increase in CHA₂DS₂-VASc score was associated with a 38% increased risk for the composite endpoint, a 19% increased risk for 1-year myocardial infarction, and a 29% increased risk for 1-year stroke. Conclusions: Patients with ESRD are at an extremely high mortality and cardiovascular risk within the first year of hemodialysis. The CHA₂DS₂-VASc score was strongly associated with adverse outcomes and may be used for risk stratification of these patients.