Sclerostin, a Wnt antagonist produced by osteocytes, regulates osteoblast activity and is a well-established key player in bone turnover. Recent data indicate that the Wnt pathway may also be involved in vascular calcification. The present study tests the hypothesis that serum sclerostin levels are associated with vascular calcification in patients with chronic kidney disease (CKD) not yet receiving dialysis. We performed a cross-sectional analysis in 154 patients with CKD. Aortic calcification (AC) was assessed by lumbar X-ray and scored with a maximum score of 24. In addition to traditional and nontraditional cardiovascular (CV) risk factors, serum sclerostin levels were assessed (ELISA). Regression analysis was performed to identify determinants of serum sclerostin and AC. AC was present in 59% of patients. Older age (P < .0001), male sex (P = .006), lower estimated glomerular rate (eGFR) (P = .0008), lower bone-specific alkaline phosphatase (P = .03), and the absence of AC (P = .006) were identified as independent determinants of higher serum sclerostin levels. In univariate logistic regression, higher age, diabetes, CV history, higher body mass index, higher serum C-reactive protein and sclerostin levels and lower estimated glomerular rate were all associated with the presence of AC. In multivariate analysis, lower, not higher, sclerostin levels (P = .04, odds ratio [OR] per ng/mL of 0.24), higher age (P < .0001, OR per year of 1.17) and CV history (P = .02, OR for a positive CV history of 3.83) were identified as independent determinants of AC. In this cohort of patients with CKD, we found that patients with aortic calcifications (ACs) had higher sclerostin levels. However, in multivariate analysis, the association became inverse. Additional clinical and experimental studies are urgently required to clarify whether or not sclerostin protects against progression of vascular calcification.

The recent Chandos House meeting of the Alport Variant Collaborative extended the indications for screening for pathogenic variants in theCOL4A5, COL4A3andCOL4A4genes beyond the classical Alport phenotype (haematuria, renal failure; family history of haematuria or renal failure) to include persistent proteinuria, steroid-resistant nephrotic syndrome, focal and segmental glomerulosclerosis (FSGS), familial IgA glomerulonephritis and end-stage kidney failure without an obvious cause. The meeting refined the ACMG criteria for variant assessment for the Alport genes (COL4A3–5). It identified ‘mutational hotspots’ (PM1) in the collagen IV α5, α3 and α4 chains including position 1 Glycine residues in the Gly-X-Y repeats in the intermediate collagenous domains; and Cysteine residues in the carboxy non-collagenous domain (PP3). It considered that ‘well-established’ functional assays (PS3, BS3) were still mainly research tools but sequencing and minigene assays were commonly used to confirm splicing variants. It was not possible to define the Minor Allele Frequency (MAF) threshold above which variants were considered Benign (BA1, BS1), because of the different modes of inheritances of Alport syndrome, and the occurrence of hypomorphic variants (often Glycine adjacent to a non-collagenous interruption) and local founder effects. HeterozygousCOL4A3andCOL4A4variants were common ‘incidental’ findings also present in normal reference databases. The recognition and interpretation of hypomorphic variants in theCOL4A3–COL4A5genes remains a challenge.

PURPOSE: Hematopoietic stem-cell transplantation–associated thrombotic microangiopathy (HSCT-TMA) is a serious complication with significant mortality and no approved therapy. HSCT-TMA results from endothelial injury, which activates the lectin pathway of complement. Narsoplimab (OMS721), an inhibitor of mannan-binding lectin-associated serine protease-2 (MASP-2), was evaluated for safety and efficacy in adults with HSCT-TMA. METHODS: In this single-arm open-label pivotal trial ( NCT02222545 ), patients received intravenous narsoplimab once weekly for 4-8 weeks. The primary end point (response rate) required clinical improvement in two categories: (1) laboratory TMA markers (both platelet count and lactate dehydrogenase) and (2) organ function or freedom from transfusion. Patients receiving at least one dose (full analysis set [FAS]; N = 28) were analyzed. RESULTS: The response rate was 61% in the FAS population. Similar responses were observed across all patient subgroups defined by baseline features, HSCT characteristics, and HSCT complications. Improvement in organ function occurred in 74% of patients in the FAS population. One-hundred-day survival after HSCT-TMA diagnosis was 68% and 94% in FAS population and responders, respectively, whereas median overall survival was 274 days in the FAS population. Narsoplimab was well tolerated, and adverse events were typical of this population, with no apparent safety signal of concern. CONCLUSION: In this study, narsoplimab treatment was safe, significantly improved laboratory TMA markers, and resulted in clinical response and favorable overall survival.

Serum p-cresyl sulfate (PCS) associates with cardiovascular disease in patients with chronic kidney disease. PCS concentrations are determined by intestinal uptake of p-cresol, human metabolism to PCS and renal clearance. Whether intestinal uptake of p-cresol itself is directly associated with cardiovascular disease in patients with renal dysfunction has not been studied to date. We performed a prospective study in patients with chronic kidney disease stage 1 – 5 (NCT00441623). Intestinal uptake of p-cresol, under steady state conditions, was estimated from 24 h urinary excretion of PCS. Primary endpoint was time to first cardiovascular event, i.e., cardiac death, myocardial infarction/ischemia, ventricular arrhythmia, cardiovascular surgery, ischemic stroke or symptomatic peripheral arterial disease. Statistical analysis was done using Kaplan-Meier estimates and Cox proportional hazard analyses. In a cohort of 200 patients, median 24 h urinary excretion of PCS amounted to 457.47 μmol (IQR 252.68 – 697.17). After a median follow-up of 52 months, 25 patients reached the primary endpoint (tertile 1/2/3: 5/6/14 events, log rank P 0.037). Higher urinary excretion of PCS was directly associated with cardiovascular events (univariate hazard ratio per 100 μmol increase: 1.112, P 0.002). In multivariate analysis, urinary excretion of PCS remained a predictor of cardiovascular events, independent of eGFR (hazard ratio 1.120, P 0.002). In patients with chronic kidney disease, intestinal uptake of p-cresol associates with cardiovascular disease independent of renal function. The intestinal generation and absorption of p-cresol may be therapeutic targets to reduce cardiovascular disease risk in patients with renal dysfunction.

Patient activation is associated with better outcomes and lower costs. Although the concept is widely investigated, little attention was given to patient activation and its predictors in patients undergoing hemodialysis. Hence, we aimed to investigate the level of patient activation and aimed to determine patient- and treatment-related predictors of activation in patients undergoing hemodialysis. This cross-sectional observational study recruited patients undergoing hemodialysis in three Flemish hospitals. Participants were questioned about patient characteristics (i.e., age, sex, education, employment, children, social support, leisure-time, living condition, and care at home), treatment- and health-related characteristics (i.e., hospital, time since first dialysis, transplantation, self-reported health (EQ-VAS) and depressive symptoms (PHQ-2)), and patient activation (PAM-13). Univariate and multiple linear regression analyses with dummy variables were conducted to investigate the associations between the independent variables and patient activation. The average patient activation-score was 51. Of 192 patients, 44% patients did not believe they had an important role regarding their health. Multiple linear regression showed that older patients, who reported being in bad health, treated in a particular hospital, without leisure-time activities, and living in a residential care home, had lower patient activation. These variables explained 31% of the variance in patient activation. Based on literature, we found that activation of patients on hemodialysis is low, compared to that of other chronic patient groups. It could be useful to implement patient activation monitoring, since the level of activation is low in patients undergoing hemodialysis. Older patients, who reported being in bad health, treated in a particular hospital, without leisure-time activities, living in a residential care home, are at higher risk for lower activation.

Background: The identification of complement defects as major drivers of primary atypical hemolytic uremic syndrome (HUS) has transformed the landscape of thrombotic microangiopathies (TMAs), leading to the development of targeted therapies and better patient outcomes. By contrast, little is known about the presentation, genetics, and outcomes of TMA associated with specific diseases or conditions, also referred to as secondary TMA. Methods: In this study, we assessed the relative incidence, clinical and genetic spectra, and long-term outcomes of secondary TMA versus other TMAs in consecutive patients hospitalized with a first episode of TMA from 2009 to 2019 at two European reference centers. Results: During the study period, 336 patients were hospitalized with a first episode of TMA. Etiologies included atypical HUS in 49 patients (15%), thrombotic thrombocytopenic purpura (TTP) in 29 (9%), shigatoxin-associated HUS in 70 (21%), and secondary TMA in 188 (56%). The main causes of secondary TMA were hematopoietic stem-cell transplantation (n=56, 30%), solid-organ transplantation (n=44, 23%), and malignant hypertension (n=25, 13%). Rare variants in complement genes were identified in 32 of 49 patients (65%) with atypical HUS and eight of 64 patients (13%) with secondary TMA; pathogenic or likely pathogenic variants were found in 24 of 49 (49%) and two of 64 (3%) of them, respectively (P < 0.001). After a median follow-up of 1157 days, death or kidney failure occurred in 14 (29%), eight (28%), five (7%), and 121 (64%) patients with atypical HUS, TTP, shigatoxin-associated HUS, and secondary TMA, respectively. Unadjusted and adjusted Cox regressions showed that patients with secondary TMA had the highest risk of death or kidney failure (unadjusted hazard ratio [HR], 3.35; 95% confidence interval [CI], 1.85 to 6.07; P < 0.001; adjusted HR, 4.11; 95% CI, 2.00 to 8.46; P < 0.001; considering atypical HUS as reference). Conclusions: Secondary TMAs represent the main cause of TMA and are independently associated with a high risk of death and progression to kidney failure.