Description of a New Simple and Cost-Effective Molecular Testing That Could Simplify MUC1 Variant Detection.

Introduction: Patients with autosomal dominant tubulointerstitial kidney disease (ADTKD) usually present with nonspecific progressive chronic kidney disease (CKD) with mild to negative proteinuria and a family history. ADTKD-MUC1 leads to the formation of a frameshift protein that accumulates in the cytoplasm, leading to tubulointerstitial damage. ADTKD-MUC1 prevalence remains unclear because MUC1 variants are not routinely detected by standard next-generation sequencing (NGS) techniques. Methods: We developed a bioinformatic counting script that can detect specific genetic sequences and count the number of occurrences. We used DNA samples from 27 patients for validation, 11 of them were patients from the Lille University Hospital in France and 16 were from the Wake Forest Hospital, NC. All patients from Lille were tested with an NGS gene panel with our script and all patients from Wake Forest Hospital were tested with the snapshot reference technique. Between January 2018 and February 2023, we collected data on all patients diagnosed with MUC1 variants with this script. Results: A total of 27 samples were tested anonymously by the BROAD Institute reference technique for confirmation and we were able to get a 100% concordance for MUC1 diagnosis. Clinico-biologic characteristics in our cohort were similar to those previously described in ADTKD-MUC1. Conclusion: We describe a new simple and cost-effective method for molecular testing of ADTKD-MUC1. Genetic analyses in our cohort suggest that MUC1 might be the first cause of ADTKD. Increasing the availability of MUC1 diagnosis tools will contribute to a better understanding of the disease and to the development of specific treatments.

Extracorporeal Photopheresis Reduces Fibrotic and Inflammatory Transcriptomic Biological Marker of Chronic Antibody-mediated Kidney Rejection.

Background: The benefit of extracorporeal photopheresis on the course of kidney transplant rejection is unknown. The aim of our study was to investigate the variations in transcriptomics on graft biopsies when extracorporeal photopheresis was used to treat chronic humoral rejection after kidney transplantation. Methods: We retrospectively analyzed the mRNA expression of 770 genes of interest in graft biopsies performed before and after treatment. Eight patients received an average of 23 extracorporeal photopheresis sessions over 4 mo between the 2 biopsies. Results: Transcriptomic analysis of the graft biopsies identified a significant (adjusted P < 0.05) increase in CAV1 mRNA in all patients and a significant decrease in CD19, IL21, PAX5, and SFTPA2 mRNAs in 7 of 8 patients. Conclusions: In patients treated with extracorporeal photopheresis for chronic humoral rejection after renal transplantation, omic analysis of repeated biopsies shows a reduction in fibrotic and inflammatory transcriptomic biologicals markers.

Proteinuria reduction with SGLT2 inhibitors in a patient treated with tyrosine kinase inhibitor lenvatinib.

We describe the case of a 66-year-old woman treated with tyrosine kinase inhibitor Lenvatinib for thyroid carcinoma who had persistent proteinuria above 2 g/24 h despite maximal dose of angiotensin-converting enzyme inhibitor. We initiated a treatment with SGLT2 inhibitor Dapagliflozin. Three months after Dapagliflozin initiation, her proteinuria decreased to 1 g/24 h, and after 6 months of follow-up was 0.6 g/24 h. To our knowledge, this is the first case of successful proteinuria reduction with SGLT2i in a patient treated with Lenvatinib. Specific renal effects of SGLT2i seem promising and their effects on tyrosine kinase inhibitor renal adverse effects need to be validated in clinical trials involving cancer patients.

Impaired renal function before kidney procurement has a deleterious impact on allograft survival in very old deceased kidney donors.

As the use of elderly kidney donors for transplantation is increasing with time, there is a need to understand which factors impact on their prognosis. No data exist on the impact of an impaired renal function (IRF) in such population. 116 kidney recipients from deceased kidney donors over 70 years were included from 2005 to 2015 in a single-center retrospective study. IRF before organ procurement was defined as a serum creatinine above 1.0 mg/dl or a transient episode of oligo-anuria. Mean ages for donors and recipients were respectively 74.8 ± 3.5 and 66.7 ± 8.0. Graft survival censored for death at 5 years was of 77%. Using a multivariate analysis by Cox model, the only predictor of graft loss present in the donor was IRF before organ procurement (HR 4.2 CI95[1.8-9.7]). IRF was also associated with significant lower estimated glomerular filtration rates up to 1 year post-transplantation. By contrast, KDPI score (median of 98 [96-100]), was not associated with the risk of graft failure. Then, IRF before kidney procurement may define a risk subgroup among very-old deceased kidney donors, in whom pre-implantatory biopsies, dual kidney transplantation or calcineurin inhibitor-free immunosuppressive regimen could help to improve outcomes.

Urgent-start dialysis in patients referred early to a nephrologist-the CKD-REIN prospective cohort study.

BACKGROUND: The lack of a well-designed prospective study of the determinants of urgent dialysis start led us to investigate its individual- and provider-related factors in patients seeing nephrologists. METHODS: The Chronic Kidney Disease Renal Epidemiology and Information Network (CKD-REIN) is a prospective cohort study that included 3033 patients with CKD [mean age 67 years, 65% men, mean estimated glomerular filtration rate (eGFR) 32 mL/min/1.73 m2] from 40 nationally representative nephrology clinics from 2013 to 2016 who were followed annually through 2020. Urgent-start dialysis was defined as that 'initiated imminently or <48 hours after presentation to correct life-threatening manifestations' according to the Kidney Disease: Improving Global Outcomes 2018 definition. RESULTS: Over a 4-year (interquartile range 3.0-4.8) median follow-up, 541 patients initiated dialysis with a known start status and 86 (16%) were identified with urgent starts. The 5-year risks for the competing events of urgent and non-urgent dialysis start, pre-emptive transplantation and death were 4, 17, 3 and 15%, respectively. Fluid overload, electrolytic disorders, acute kidney injury and post-surgery kidney function worsening were the reasons most frequently reported for urgent-start dialysis. Adjusted odds ratios for urgent start were significantly higher in patients living alone {2.14 [95% confidence interval (CI) 1.08-4.25] or with low health literacy [2.22 (95% CI 1.28-3.84)], heart failure [2.60 (95% CI 1.47-4.57)] or hyperpolypharmacy [taking >10 drugs; 2.14 (95% CI 1.17-3.90)], but not with age or lower eGFR at initiation. They were lower in patients with planned dialysis modality [0.46 (95% CI 0.19-1.10)] and more nephrologist visits in the 12 months before dialysis [0.81 (95% CI 0.70-0.94)] for each visit. CONCLUSIONS: This study highlights several patient- and provider-level factors that are important to address to reduce the burden of urgent-start dialysis.

Donor-to-recipient transmission and reactivation in a kidney transplant recipient of an inherited chromosomally integrated HHV-6A: Evidence and outcomes.

Human herpesvirus (HHV)-6A can be inherited and chromosomally integrated (iciHHV-6A), and donor-to-recipient transmission has been reported in solid organ transplant. However, when HHV-6A reactivation happens after transplant, the source of HHV-6A is often not evident and its pathogenicity remains unclear. Here, we present an exhaustive case of donor-to-recipient transmission and reactivation of iciHHV-6A through kidney transplant. The absence of HHV-6A genome from the nails of the recipient excluded a recipient-related iciHHV-6A. Viral loads > 7 log10 copies/106 cells in donor blood samples and similarities of U38, U39, U69, and U100 viral genes between donor, recipient, and previously published iciHHV-6A strains are proof of donor-related transmission. Detection of noncoding HHV-6 snc-RNA14 using fluorescence in situ hybridization analysis and immunofluorescence staining of HHV-6A gp82/gp105 late proteins on kidney biopsies showed evidence of reactivation in the transplanted kidney. Because HHV-6A reactivation can be life threatening in immunocompromised patients, we provide several tools to help during the complete screening and diagnosis.