The Bone-Vascular Axis in Chronic Kidney Disease: From Pathophysiology to Treatment.

PURPOSE OF REVIEW: This review aims to describe the pathogenic factors involved in bone-vessel anomalies in CKD which are the object of numerous experimental and clinical research. RECENT FINDINGS: Knowledge on the pathophysiological mechanisms involved in the regulation of vascular calcification and mineral-bone disorders is evolving. Specific bone turnover anomalies influence the vascular health while recent studies demonstrate that factors released by the calcified vessels also contribute to bone deterioration in CKD. Current therapies used to control mineral dysregulations will impact both the vessels and bone metabolism. Available anti-osteoporotic treatments used in non-CKD population may negatively or positively affect vascular health in the context of CKD. It is essential to study the bone effects of the new therapeutic options that are currently under investigation to reduce vascular calcification. Our paper highlights the complexity of the bone-vascular axis and discusses how current therapies may affect both organs in CKD.

Determinants of urgent start dialysis in a chronic kidney disease cohort followed by nephrologists.

BACKGROUND: The French Renal Epidemiology and Information Network (REIN) registry collect dialysis initiation context for each patient starting dialysis with a flawed definition of urgent start dialysis (USD). The main objective of this study was to identify factors associated with USD in patients regularly followed-up by a nephrologist using a classification of USD considering the preparation to renal replacement therapy. METHODS: This retrospective cohort study included adult patients who started dialysis between 2012 and 2018 in the Franche-Comté region of France after a minimum of two nephrology consultations. We classified dialysis initiation context as follows: USD for patients with no dialysis access (DA) created or planned, unplanned non urgent start dialysis (UNUSD) for patients starting with a recent or non-functional DA and planned start dialysis (PSD) for those starting with a functional and mature DA. RESULTS: Four hundred and sixty-five patients met inclusion criteria. According to REIN registry, 94 (20.3%) patients were urgent starters (US) whereas with our classification 80 (17.2%) and 73 (15.7%) where respectively US and unplanned non urgent starters (UNUS). The factors independently associated with USD in our classification were: stroke (odds ratio(OR) = 2.76, 95% confidence interval (95%CI)=[1.41-5.43]), cardiac failure (OR = 1.78, 95%CI=[1.07-2.96]) and the number of nephrology consultations prior dialysis onset (OR = 0.73, 95%CI=[0.64-0.83]). Thirty-one patients died during the first year after dialysis start. According to our classification, we observed significantly different survival probabilities: 95.7%, 89.5% and 83.4% respectively for planned starters, UNUS and US (p = 0.001). CONCLUSION: The two factors independently associated with USD were cardiac failure and stroke.

Kidney transplantation improves the clinical outcomes of Acute Intermittent Porphyria.

BACKGROUND: Acute Intermittent Porphyria (AIP) is a rare inherited autosomal dominant disorder of heme biosynthesis. Porphyria-associated kidney disease occurs in more than 50% of the patients with AIP, and end stage renal disease (ESRD) can be a devastating complication for AIP patients. The outcomes of AIP patients after kidney transplantation are poorly known. METHODS: We examined the outcomes of 11 individuals with AIP, identified as kidney transplant recipients in the French Porphyria Center Registry. RESULTS: AIP had been diagnosed on average 19 years before the diagnosis of ESRD except for one patient in whom the diagnosis of AIP had been made 5 years after the initiation of dialysis. Median follow-up after transplantation was 9 years. A patient died 2 months after transplantation from a cardiac arrest and a patient who received a donation after cardiac death experienced a primary non-function. No rejection episode and no noticeable adverse event occurred after transplantation. Serum creatinine was on average 117 µmol/l, and proteinuria <0.5 g/l in all patients at last follow up. All usually prescribed drugs after transplantation are authorized except for trimethoprim/sulfamethoxazole. Critically, acute porphyria attacks almost disappeared after kidney transplantation, and skin lesions resolved in all patients. CONCLUSION: Kidney transplantation is the treatment of choice for AIP patients with ESRD and dramatically reduces the disease activity.

Uraemia-induced immune senescence and clinical outcomes in chronic kidney disease patients.

BACKGROUND: Patients with chronic kidney disease (CKD) are more prone to develop premature age-related diseases. Data on immune senescence are scarce in CKD populations, except in end-stage renal disease and dialysis. We designed a longitudinal prospective study to evaluate immune senescence at different CKD stages and its influence on CKD patient outcomes. METHODS: Clinical and biological data collections were performed on 222 patients at different CKD stages [1-2 (n = 85), 4 (n = 53) and 5 (n = 84)]. Immune senescence biomarkers were measured by cytometry on T cells (CD28, CD57, CD45RA, CD31, γH2A.X) or by quantitative polymerase chain reaction [relative telomere length (RTL)] on peripheral blood mononuclear cells and analysed according to CKD stages and outcomes. RESULTS: CKD was associated with an increase in immune senescence and inflammation biomarkers, as follows: low thymic output (197 ± 25 versus 88 ± 13 versus 73 ± 21 CD4+CD45RA+CD31+ T cells/mm3), an increased proportion of terminally differentiated T cells (CD8+CD28-CD57+) (24 ± 18 versus 32 ± 17 versus 35 ± 19%) restricted to cytomegalovirus-positive patients, telomere shortening (1.11 ± 0.36 versus 0.78 ± 0.24 versus 0.97 ± 0.21 telomere:single copy ratio) and an increase in C-reactive protein levels [median 2.9 (range 1.8-4.9) versus 5.1 (27-9.6) versus 6.2 (3.4-10.5) mg/L]. In multivariate analysis, shorter RTL was associated with death {hazard ratio [HR] 4.12 [95% confidence interval (CI) 1.44-11.75]}. Low thymic output was associated with infections [HR 1.79 (95% CI (1.34-9.58)] and terminally differentiated CD8+ T-cell expansion with a risk of cardiovascular events [CEs; HR 4.86 (95% CI 1.72-13.72)]. CONCLUSION: CKD was associated with premature immune ageing. Each of these alterations increased the risk of specific age-related diseases, such as RTL and death, thymic function and infections and terminally differentiated CD8+ T-cell expansion and CEs.

Peritoneal dialysis after kidney transplant failure: a nationwide matched cohort study from the French Language Peritoneal Dialysis Registry (RDPLF).

BACKGROUND: Failed kidney transplant is becoming a frequent cause of dialysis initiation. Although studies have shown no difference between peritoneal dialysis (PD) and haemodialysis (HD) in terms of patients and technique survival, PD remains quite rarely used in this condition. Studies in larger multicentre matched cohorts are missing. METHODS: We conducted a retrospective study about 328 patients registered in the French Language Peritoneal Dialysis Registry (RDPLF) who started PD after kidney transplant failure (Tx group) between January 2002 and December 2012 who were compared with 656 matched never-transplanted patients having started PD during the same period (control group). Patients and PD technique survival as well as peritonitis episodes were analysed. RESULTS: Over the study period, patients' survival was similar between the two groups (P = 0.34). The mean time on PD was significantly shorter for patients in the Tx group [17 months (range 14-20)] compared with the control group [21 months (range 19-23)] (P = 0.003). The main cause of transfer to HD was for both group adequacy and/or ultrafiltration failure. Peritonitis rates were similar in the two groups: 43.6% (n = 143) versus 40.1% (n = 263) in the Tx and control group, respectively (P = 0.3). In multivariate Cox analysis, kidney transplant failure (P < 0.0001), younger age (P = 0.02) and male gender (P = 0.01) were associated with a higher risk of transfer to HD. Using multivariate competing risk analysis, kidney transplant failure was again observed as a predictive factor (P < 0.0001), but not age and gender. The only other significant predictive factor observed was peritonitis episodes experienced during PD treatment (P = 0.002). CONCLUSIONS: Comparing the Tx and control groups, we report similar patient survival and peritonitis rates but a higher PD technique failure in the Tx group.

A Program for Weaning Children from Enteral Feeding in a General Pediatric Unit: How, for Whom, and with What Results?

OBJECTIVE: To describe a series of children who were hospitalized for a tube-weaning program in the general pediatric ward of a pediatric tertiary university hospital: describe our method, to determine the success rate of our inpatient pediatric tube weaning program, and search for relevant factors linked to its success or failure. METHOD: We analyzed the medical files of consecutive children who were hospitalized for gastric-tube weaning over an 8-year period. We analyzed outcomes in terms of feeding and growth with at least 2 years of data. Success (weaning within 3 months) and failure were compared by characteristics of children. RESULTS: We included 37 children (29 females) with mean (SD) age 31.4 (21) months. Most had a severe medical history (30% prematurity; 50% intrauterine growth restriction, 50% neurological and genetic anomalies). The weaning program was successful for half of the children. Factors linked to success of the program were female sex (p = 0.0188), normal neurodevelopment (p = 0.0016), nasogastric tube (p = 0.0098), and with <24 months on EF before the stay (p = 0.0309). DISCUSSION: Comparing the efficiency of various methods and results among teams was difficult, which indicates the need to establish consensus about the outcome criteria. We confirm the need for these types of stays and programs.