The kind of fluidized-bed BLADs based on microencapsulated primary porcine hepatocytes have risk of PERVs transmission. Further extensive pre-clinical study focused on biosafety is warranted.

Akizawa et al. 1 report roxadustat's noninferiority to darbepoetin alfa in treating hemodialysis-dependent CKD anemia in their phase 3 study. However, in this trial, we could not find the exact data of the primary disease of CKD or the proportion that polycystic kidney disease (PKD) 1-4 accounts for. PKD is the fourth leading cause of ESKD in adults worldwide; however, in a phase 2 trial of roxadustat in CKD-associated anemia in Japanese patients, the ratio of polycystic kidney disease was 6.3% (five in 80). 2 Roxadustat and other hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitors induce hypoxia-like conditions within the cell by stabilizing HIFs and regulating the downstream pathway. Meanwhile, the HIF pathway has been identified as an important novel mechanism of cyst progression through chloride secretion, apoptosis, cell proliferation, cell metabolism, and inflammation in PKD. 3 Further, application of a prolyl-hydroxylase inhibitor resulted in severe aggravation of the mild phenotype. 4 Although HIF prolyl hydroxylase inhibitors offer several important advantages, we caution that the long-term use of roxadustat might induce the growth and enlargement of renal cysts in patients with PKD, which can lead to adverse events such as bleeding and infection. Given the data of these trials and hypothesis, the total kidney volume of patients with PKD should be monitored carefully, and these patients deserve longterm follow-up.

Future research should focus on investigating early markers of CNI nephrotoxicity and strategies for improved immunosuppressant therapy, and developing alternative treatments. CNI-mediated nephrotoxicity should always be taken seriously in clinic.

Background: The coronavirus disease 2019 (COVID-19) pandemic continues to spread around the world. Vaccinations have been administered globally and have been proven to be safe and effective. However, vasculitis has been reported as an adverse event occurring after COVID-19 vaccination. Methods: In this review, we analyzed the literature to identify original articles that reported on patients who developed vasculitis following COVID-19 vaccination and summarized their clinical manifestations. PubMed and Web of Knowledge were searched to identify relevant studies. Results: A total of 27 patients who developed vasculitis following COVID-19 vaccination were identified from 21 studies. The involved organs included the skin and kidney. The main clinical features of patients whose skin was affected were papules, maculopapular rashes, and plaques. Most of the patients exhibited small vessel vasculitis and single-organ vasculitis; these were resolved within one month. Patients whose kidneys were affected exhibited vasculitis, including anti-neutrophil cytoplasmic antibody glomerulonephritis and IgA nephritis. Most patients were treated with corticosteroid, rituximab, and cyclophosphamide, and one patient needed hemodialysis. The renal function of most patients was improved or recovered, but one patient needed maintenance dialysis. Conclusion: Vasculitis was rarely reported after COVID-19 vaccine administration. It often manifested as cutaneous small-vessel vasculitis or glomerulonephritis. Notably, when a patient demonstrates hematuria, proteinuria, and acute kidney injury after COVID-19 vaccination, there is a possibility that the patient could have developed vasculitis. Skin-related problems were quickly resolved, while kidney-related problems may progress to chronic kidney disease.

<b><i>Background:</i></b> Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disorder, accounting for approximately 5% of all ESRD cases worldwide. As a vasopressin receptor 2 antagonist, tolvaptan is the FDA-approved therapeutic agent for ADPKD, which is only made available to a limited number of adult patients; however, its efficacy in pediatric patients has not been reported widely. <b><i>Summary:</i></b> Tolvaptan was shown to delay ADPKD progression in the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Its Outcomes (TEMPO) 3:4 study, Replicating Evidence of Preserved Renal Function: an Investigation of Tolvaptan Safety and Efficacy in ADPKD (REPRISE) trial, and other clinical studies. In addition to its effects on aquaretic adverse events and alanine aminotransferase elevation, the effect of tolvaptan on ADPKD is clear, sustained, and cumulative. While ADPKD is a progressive disease, the early intervention has been shown to be important and beneficial in hypotheses as well as in trials. The use of tolvaptan in pediatric ADPKD involves the following challenges: patient assessment, quality of life assessment, cost-effectiveness, safety, and tolerability. The ongoing, phase 3b, 2-part study (ClinicalTrials.gov identifier: NCT02964273) on the evaluation of tolvaptan in pediatric ADPKD (patients aged 12–17 years) may help obtain some insights. <b><i>Key Messages:</i></b> This review focuses on the rationality of tolvaptan use in pediatric patients with ADPKD, the associated challenges, and the suggested therapeutic approaches.