Clinical significance of serum urea-to-creatinine ratio in patients undergoing peritoneal dialysis.

INTRODUCTION: We aimed to determine the correlation between the serum urea-to-creatinine ratio and residual kidney function (RKF) in patients undergoing peritoneal dialysis (PD), as well as its predictive value for PD-related outcomes. METHODS: This study included a cross-sectional study to assess the correlation between serum urea-to-creatinine ratio and RKF in 50 patients on PD and a retrospective cohort study to assess the association between serum urea-to-creatinine ratio and PD-related outcomes in 122 patients who initiated PD. RESULTS: Serum urea-to-creatinine ratios had significant positive correlations with renal Kt/V and creatinine clearance values (r = 0.60, p < 0.001 and r = 0.61, p < 0.001, respectively). Additionally, serum urea-to-creatinine ratio was significantly associated with a lower risk of transfer to hemodialysis or PD/hemodialysis hybrid therapy (hazard ratio: 0.84, 95% confidence interval: 0.75-0.95). CONCLUSION: The serum urea-to-creatinine ratio can be an indicator of RKF and a prognostic factor in patients undergoing PD.

The body mass index change is associated with death or hemodialysis transfer in Japanese patients initiating peritoneal dialysis.

A decreased body mass index (BMI) over time is associated with a poor prognosis for patients on hemodialysis. We aimed to examine whether this association also applies to patients with peritoneal dialysis (PD). BMI change was defined as the percentage change in the BMI between the time of PD catheter insertion and six months after its insertion. The association between the BMI change and all-cause mortality or PD discontinuation from six months after PD catheter insertion until October 2021 was investigated. This retrospective cohort study included 122 patients (aged 61.1 ± 12.1 years; 90 males) who underwent PD catheter insertion between January 2008 and March 2020. The median follow-up period was 43.1 (21.2-78.8) months. The median six-month percentage change in the BMI was -2.14 (-5.56-1.84)%, and patients were categorized into tertiles based on their BMI changes. The fully-adjusted Cox regression analysis revealed a significantly higher rate of PD discontinuation or all-cause mortality (hazard ratio (HR): 2.48; 95%; confidence interval (CI): 1.41-4.37) in patients with the lowest tertile (T1, BMI change: < -4.13%) compared to patients with the middle tertile (T2, BMI change: -4.13%-0.67%). The risk was not significantly higher in patients with the highest tertile (T3, BMI change: >0.67%) than those in the T2 group (HR: 1.18; 95% CI: 0.66-2.11). A decreased BMI over time is independently associated with HD transfer or all-cause mortality among patients initiating PD, which highlights the importance of the 6-month BMI change as a novel prognostic marker.

Effect of Tolvaptan in Patients with Chronic Kidney Disease Stage G5, and Impact of Concomitant Use of Thiazide Diuretics: A Retrospective Cohort Study.

BACKGROUND: The diuretic effect of tolvaptan, a vasopressin V2 receptor antagonist, in patients with severe renal dysfunction remains poorly characterized. Thiazide diuretics reduce urinary volume (UV) in patients with nephrogenic diabetes insipidus, which lacks V2 receptor function. OBJECTIVE: This retrospective study investigated the acute urinary effects of tolvaptan in patients with stage G5 chronic kidney disease and congestive heart failure (CHF), and the impact of thiazide diuretics on the urinary effects of tolvaptan. METHODS: UVs 24 h before and after tolvaptan administration and 30-day dialysis initiation rate were compared between patients with and without thiazide diuretic administration. RESULTS: Thiazide diuretics were used in 26 of the 106 recruited patients (age 73.4 ± 13.0 years; estimated glomerular filtration rate 8.07 ± 3.13 mL/min/1.73 m2). The pre- and post-tolvaptan 24-h UVs were significantly higher in patients not administered thiazide diuretics (1043.4 ± 645.6 vs. 1422.2 ± 774.0 mL/day; p < 0.001) than in those administered thiazide diuretics (1177.3 ± 686.5 vs. 1173.1 ± 629.1 mL/day; p = 0.93). In a multivariate regression model, thiazide diuretic use was significantly associated with decreased 24-h UV (ß coefficient - 486.7, 95% confidence interval [CI] - 674.5 to - 298.8); increased urine osmolality (ß coefficient 37.7, 95% CI 17.1-58.4); increased body weight (ß coefficient 0.62, 95% CI 0.31-0.92); and increased 30-day dialysis initiation rate (odds ratio 3.40, 95% CI 1.18-9.82) after tolvaptan administration. CONCLUSIONS: Tolvaptan exhibited significant diuretic effects in patients with CHF, including those with severe renal dysfunction, which were diminished with concomitant thiazide diuretic use.

High body mass index is a risk factor for transition to hemodialysis or hybrid therapy and peritoneal dialysis-related infection in Japanese patients undergoing peritoneal dialysis.

PURPOSE: Obesity may negatively impact the clinical outcomes of patients undergoing peritoneal dialysis (PD). However, the impact of obesity on PD-related outcomes remains unclear. We herein examined the association of high body mass index (BMI) with complete hemodialysis (HD) transfer, transition to HD and PD/HD hybrid therapy, peritonitis, catheter exit-site and tunnel infection (ESI/TI), and heart failure-related hospitalization. METHODS: This retrospective cohort study included 120 patients who underwent PD-catheter insertion between January 2008 and June 2018. BMI ≥ 25 kg/m2 at the time of PD-catheter insertion was defined as high BMI, and its association with outcomes was analyzed using the log-rank test and Cox proportional hazards models. RESULTS: The follow-up duration was 46.2 (23.3-75.3) months. The time until transfer to HD and hybrid therapy was significantly shorter in the high BMI group than that in the low BMI group, whereas the time until HD transfer was not significantly different between the two groups (P < 0.001 and 0.18, respectively). Peritonitis-free and ESI/TI-free survivals were significantly shorter in the high BMI group than those in the low BMI group (P = 0.006 and 0.03, respectively). After adjusting for age, sex, diabetes mellitus, and estimated glomerular filtration rate, high BMI remained a significant risk factor for transferring to HD and hybrid therapy, peritonitis, and ESI/TI (hazard ratio [HR] 2.60, P < 0.001; HR 2.08, P = 0.01; HR 2.64, P = 0.02, respectively). CONCLUSION: BMI ≥ 25 kg/m2 is a risk factor for transition to HD and hybrid therapy, peritonitis, and ESI/TI, but not for complete HD transfer in Japanese patients with PD.

Health-Related Quality of Life Sleep Score Predicts Transfer to Hemodialysis among Patients on Peritoneal Dialysis.

Despite the superiority of peritoneal dialysis (PD) over hemodialysis (HD) regarding health-related quality of life (HRQOL), the specific HRQOL domain(s) that predict unplanned HD transfer remains uncertain. In this cohort study, we assessed the HRQOL of 50 outpatients undergoing PD using the Japanese version 1.3 Kidney Disease Quality of Life-Short Form from March 2017 to March 2018 and prospectively analyzed the association of each HRQOL component with HD transfer until June 2021. During the follow-up (41.5 (13.0-50.1) months), 21 patients were transferred to HD. In a multivariate Cox proportional hazards model adjusted for age, sex, PD vintage, urine output, Charlson comorbidity index, and incremental shuttle walking test, a higher sleep score was significantly associated with lower HD transfer rates (HR 0.70 per 10, p = 0.01). An adjusted subdistribution hazard model where elected transition to HD, death, and transplantation were considered competing events of unintended HD transfer that showed sleep score as an exclusive predictor of HD transfer (HR 0.70 per 10, p = 0.002). Our results suggest that sleep score among the HRQOL subscales is instrumental in predicting HD transfer in patients undergoing PD.

Development of Alveolar Hemorrhage After Pfizer-BioNTech COVID-19 mRNA Vaccination in a Patient With Renal-Limited Anti-neutrophil Cytoplasmic Antibody-Associated Vasculitis: A Case Report.

Since the coronavirus disease 2019 (COVID-19) pandemic continues and a new variant of the virus has emerged, the COVID-19 vaccination campaign has progressed. Rare but severe adverse outcomes of COVID-19 vaccination such as anaphylaxis and myocarditis have begun to be noticed. Of note, several cases of new-onset antineutrophil cytoplasmic antibody-associated vasculitis (AAV) after COVID-19 mRNA vaccination have been reported. However, relapse of AAV in remission has not been recognized enough as an adverse outcome of COVID-19 vaccination. We report, to our knowledge, a first case of renal-limited AAV in remission using every 6-month rituximab administration that relapsed with pulmonary hemorrhage, but not glomerulonephritis, following the first dose of the Pfizer-BioNTech COVID-19 vaccine. The patient received the COVID-19 vaccine more than 6 months after the last dose of rituximab according to the recommendations. However, his CD19+ B cell counts were found to be increased after admission, indicating that our case might have been prone to relapse after COVID-19 vaccination. Although our case cannot establish causality between AAV relapse and COVID-19 mRNA vaccination, a high level of clinical vigilance for relapse of AAV especially in patients undergoing rituximab maintenance therapy following COVID-19 vaccination should be maintained. Furthermore, elapsed time between rituximab administration and COVID-19 mRNA vaccination should be carefully adjusted based on AAV disease-activity.