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Kidney allotransplantation remains the preferred treatment for end-stage kidney disease, yet donor shortages limit its availability. Xenotransplantation using genetically modified porcine kidneys offers a promising alternative. Here, we report key physiological observations from the first-in-human porcine kidney xenograft over a 51 day postoperative follow-up period. The transplanted kidney maintained essential functions, including waste excretion, electrolyte regulation, and production of concentrated urine, while supporting blood pressure and sodium reabsorption despite reduced activation of the renin-angiotensin-aldosterone system. Sodium retention required diuretic therapy, and mild hypocalcemia and hyperphosphatemia occurred in the setting of pre-existing hypoparathyroidism. Markedly increased urinary uric acid excretion led to hypouricemia without evidence of urate nephropathy. This case demonstrates the ability of a porcine kidney to sustain vital metabolic functions in a living human, while highlighting areas for further research. These findings provide a foundation for optimizing post-transplant care and advancing xenotransplantation as a solution to the critical organ shortage. Kidney shortages limit treatment options for patients with end-stage kidney disease, prompting exploration of xenotransplantation. Here, the authors show that a genetically modified pig kidney sustained essential functions in a living human for 51 days, informing future clinical strategies.

The kidney tubules constitute two-thirds of the cells of the kidney and account for the majority of the organ’s metabolic energy expenditure. Acute tubular injury (ATI) is observed across various types of kidney diseases and may significantly contribute to progression to kidney failure. Non-invasive biomarkers of ATI may allow for early detection and drug development. Using the SomaScan proteomics platform on 434 patients with biopsy-confirmed kidney disease, we here identify plasma biomarkers associated with ATI severity. We employ regional transcriptomics and proteomics, single-cell RNA sequencing, and pathway analysis to explore biomarker protein and gene expression and enriched biological pathways. Additionally, we examine ATI biomarker associations with acute kidney injury (AKI) in the Kidney Precision Medicine Project (KPMP) ( n  = 44), the Atherosclerosis Risk in Communities (ARIC) study ( n  = 4610), and the COVID-19 Host Response and Clinical Outcomes (CHROME) study ( n  = 268). Our findings indicate 156 plasma proteins significantly linked to ATI with osteopontin, macrophage mannose receptor 1, and tenascin C showing the strongest associations. Pathway analysis highlight immune regulation and organelle stress responses in ATI pathogenesis. Acute tubular injury (ATI) significantly contributes to many kidney diseases. Here, the authors identify several immune response and cellular stress plasma proteins linked to ATI severity and acute kidney injury, which may aid in non-invasive ATI assessment.

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease with high morbidity and mortality. The cellular source of the fibrotic process is currently under debate with one suggested mechanism being epithelial-to-mesenchymal transition (EMT) in the alveolar region. In this study, we show that airway epithelium overlying fibroblastic foci in IPF contains a layer of p63-positive basal cells while lacking ciliated and goblet cells. This basal epithelium shows increased expression of CK14, Vimentin and N-cadherin while retaining E-cadherin. The underlying fibroblastic foci shows both E- and N-cadherin-positive cells. To determine if p63-positive basal cells were able to undergo EMT in culture, we treated VA10, a p63-positive basal cell line, with the serum replacement UltroserG. A sub-population of treated cells acquired a mesenchymal phenotype, including an E- to N-cadherin switch. After isolation, these cells portrayed a phenotype presenting major hallmarks of EMT (loss of epithelial markers, gain of mesenchymal markers, increased migration and anchorage-independent growth). This phenotypic switch was prevented in p63 knockdown (KD) cells. In conclusion, we show that airway epithelium overlying fibroblastic foci in IPF lacks its characteristic functional identity, shows increased reactivity of basal cells and acquisition of a partial EMT phenotype. This study suggests that some p63-positive basal cells are prone to phenotypic changes and could act as EMT progenitors in IPF.

The antithrombotic effect of vitamin K antagonists (VKA) depends on controlled lowering of the activity of factors (F) II and X whereas reductions in FVII and FIX play little role. PT-INR based monitoring, however, is highly influenced by FVII, which has the shortest half-life of vitamin K-dependent coagulation factors. Hence, variability in the anticoagulant effect of VKA may be partly secondary to an inherent flaw of the traditional monitoring test itself. The Fiix prothrombin time (Fiix-PT) is a novel test that is only sensitive to reductions in FII and FX and is intended to stabilize the VKA effect. Two clinical studies have now demonstrated that when warfarin is monitored with the Fiix-PT based normalized ratio (Fiix-NR) instead of PT-INR, anticoagulation is stabilized and less testing and fewer dose adjustments are needed. Furthermore, the relative risk of thromboembolism was reduced by 50–56% in these studies without an increase in major bleeding.

Urine sediment microscopy is commonly performed during the evaluation of kidney disease. Interobserver reliability of nephrologists' urine sediment examination has not been well studied. Assess interobserver reliability of the urine sediment examination. In this diagnostic test study, urine samples were prospectively collected from a convenience sample of adult patients from an academic hospital in the United States undergoing kidney biopsy from July 11, 2018, to March 20, 2019. Digital images and videos of urine sediment findings were captured using a bright-field microscope. These images and videos along with urine dipstick results were incorporated in online surveys and sent to expert nephrologists at 15 US teaching hospitals. They were asked to identify individual sediment findings and the most likely underlying disease process. Urine dipstick results and urine sediment images from patients undergoing native kidney biopsy. Interobserver reliability of urine sediment microscopy findings estimated by overall percent agreement and Fleiss κ coefficients. Secondary outcomes included concordance of diagnoses suspected by nephrologists with corresponding kidney biopsy results. In total, 10 surveys from 10 patients containing 76 study questions on individual features were sent to 21 nephrologists, 14 (67%) of whom completed them all. Their combined 1064 responses were analyzed. Overall percent agreement for casts was an estimated 59% (95% CI, 50%-69%), κ = 0.52 (95% CI, 0.42-0.62). For other sediment findings, overall percent agreement was an estimated 69% (95% CI, 61%-77%), κ = 0.65 (95% CI, 0.56-0.73). The κ estimates ranged from 0.13 (95% CI, 0.10-0.17) for mixed cellular casts to 0.90 (95% CI, 0.87-0.94) for squamous epithelial cells. In this study, substantial variability occurred in the interpretation of urine sediment findings, even among expert nephrologists. Educational or technological innovations may help improve the urine sediment as a diagnostic tool.

Background Protein biomarkers may provide insight into kidney disease pathology but their use for the identification of phenotypically distinct kidney diseases has not been evaluated. Methods We used unsupervised hierarchical clustering on 225 plasma biomarkers in 541 individuals enrolled into the Boston Kidney Biopsy Cohort, a prospective cohort study of individuals undergoing kidney biopsy with adjudicated histopathology. Using principal component analysis, we studied biomarker levels by cluster and examined differences in clinicopathologic diagnoses and histopathologic lesions across clusters. Cox proportional hazards models tested associations of clusters with kidney failure and death. Results We identified three biomarker-derived clusters. The mean estimated glomerular filtration rate was 72.9 ± 28.7, 72.9 ± 33.4 and 39.9 ± 30.4 mL/min/1.73 m2 in Clusters 1, 2 and 3, respectively. The top-contributing biomarker in Cluster 1 was AXIN, a negative regulator of the Wnt signaling pathway. The top-contributing biomarker in Clusters 2 and 3 was Placental Growth Factor, a member of the vascular endothelial growth factor family. Compared with Cluster 1, individuals in Cluster 3 were more likely to have tubulointerstitial disease (P < .001) and diabetic kidney disease (P < .001) and had more severe mesangial expansion [odds ratio (OR) 2.44, 95% confidence interval (CI) 1.29, 4.64] and inflammation in the fibrosed interstitium (OR 2.49 95% CI 1.02, 6.10). After multivariable adjustment, Cluster 3 was associated with higher risks of kidney failure (hazard ratio 3.29, 95% CI 1.37, 7.90) compared with Cluster 1. Conclusion Plasma biomarkers may identify clusters of individuals with kidney disease that associate with different clinicopathologic diagnoses, histopathologic lesions and adverse outcomes, and may uncover biomarker candidates and relevant pathways for further study. Lay Summary In this study, we used a computational algorithm to explore whether different subgroups of patients with chronic kidney disease can be identified based on measurements of 225 blood proteins. We found that three subgroups, or clusters, existed. These clusters associated with different types of underlying kidney diseases, different findings as seen on kidney biopsies and differing risk of progression of the disease. Our study uncovered important plasma proteins for future study and points towards the involvement of different biological pathways that may play an important role in kidney disease. These could potentially be targeted for future drug development. Graphical Abstract Graphical Abstract

Fiber-bridging stresses in carbon-fiber reinforced cements are determined by combining moiré and numerical methods. Two kinds of carbon-fibers are employed, PAN-based fibers of high stiffness and strength, and pitch-based fibers that are more compliant and lower in strength. A least-squares mapping collocation scheme that involves equilibrium, stress compatibility and complex variable methods is used to compute stresses from the moiré-measured displacements. The effectiveness and robustness of the computational scheme are verified by analytical and FEM analyses. The fiber reinforcement significantly enhances the strength and toughness of the composites. PAN-fiber reinforcement is found to be significantly more efficient than that of the pitch-fibers, in terms of both strength and toughness. Micrographs of the fracture surfaces, macro-mechanical response and equilibrium considerations substantiate current numerical/experimental results.

Long-read sequencing (LRS) promises to improve the characterization of structural variants (SVs). We generated LRS data from 3,622 Icelanders and identified a median of 22,636 SVs per individual (a median of 13,353 insertions and 9,474 deletions). We discovered a set of 133,886 reliably genotyped SV alleles and imputed them into 166,281 individuals to explore their effects on diseases and other traits. We discovered an association of a rare deletion in PCSK9 with lower low-density lipoprotein (LDL) cholesterol levels, compared to the population average. We also discovered an association of a multiallelic SV in ACAN with height; we found 11 alleles that differed in the number of a 57-bp-motif repeat and observed a linear relationship between the number of repeats carried and height. These results show that SVs can be accurately characterized at the population scale using LRS data in a genome-wide non-targeted approach and demonstrate how SVs impact phenotypes. Analysis of long-read sequencing data from 3,622 Icelanders identifies a set of high-confidence structural variants and provides insights into their effect on human traits and diseases.

This large comparative study of the Icelandic population showed that the humoral response did not decline within 4 months after infection, that 44% of persons who had been infected had not been diagnosed with qPCR, and that the infection fatality risk was 0.3%.

This cohort study estimates the proportion of persons who became reinfected with SARS-CoV-2 during the Omicron wave in Iceland.