Diagnostic Utility of Exome Sequencing for Kidney Disease.

BACKGROUND: Exome sequencing is emerging as a first-line diagnostic method in some clinical disciplines, but its usefulness has yet to be examined for most constitutional disorders in adults, including chronic kidney disease, which affects more than 1 in 10 persons globally. METHODS: We conducted exome sequencing and diagnostic analysis in two cohorts totaling 3315 patients with chronic kidney disease. We assessed the diagnostic yield and, among the patients for whom detailed clinical data were available, the clinical implications of diagnostic and other medically relevant findings. RESULTS: In all, 3037 patients (91.6%) were over 21 years of age, and 1179 (35.6%) were of self-identified non-European ancestry. We detected diagnostic variants in 307 of the 3315 patients (9.3%), encompassing 66 different monogenic disorders. Of the disorders detected, 39 (59%) were found in only a single patient. Diagnostic variants were detected across all clinically defined categories, including congenital or cystic renal disease (127 of 531 patients [23.9%]) and nephropathy of unknown origin (48 of 281 patients [17.1%]). Of the 2187 patients assessed, 34 (1.6%) had genetic findings for medically actionable disorders that, although unrelated to their nephropathy, would also lead to subspecialty referral and inform renal management. CONCLUSIONS: Exome sequencing in a combined cohort of more than 3000 patients with chronic kidney disease yielded a genetic diagnosis in just under 10% of cases. (Funded by the National Institutes of Health and others.).

Targeted-release budesonide versus placebo in patients with IgA nephropathy (NEFIGAN): a double-blind, randomised, placebo-controlled phase 2b trial.

BACKGROUND: IgA nephropathy is thought to be associated with mucosal immune system dysfunction, which manifests as renal IgA deposition that leads to impairment and end-stage renal disease in 20-40% of patients within 10-20 years. In this trial (NEFIGAN) we aimed to assess safety and efficacy of a novel targeted-release formulation of budesonide (TRF-budesonide), designed to deliver the drug to the distal ileum in patients with IgA nephropathy. METHODS: We did a randomised, double-blind, placebo-controlled phase 2b trial, comprised of 6-month run-in, 9-month treatment, and 3-month follow-up phases at 62 nephrology clinics across ten European countries. We recruited patients aged at least 18 years with biopsy-confirmed primary IgA nephropathy and persistent proteinuria despite optimised renin-angiotensin system (RAS) blockade. We randomly allocated patients with a computer algorithm, with a fixed block size of three, in a 1:1:1 ratio to 16 mg/day TRF-budesonide, 8 mg/day TRF-budesonide, or placebo, stratified by baseline urine protein creatinine ratio (UPCR). Patients self-administered masked capsules, once daily, 1 h before breakfast during the treatment phase. All patients continued optimised RAS blockade treatment throughout the trial. Our primary outcome was mean change from baseline in UPCR for the 9-month treatment phase, which was assessed in the full analysis set, defined as all randomised patients who took at least one dose of trial medication and had at least one post-dose efficacy measurement. Safety was assessed in all patients who received the intervention. This trial is registered with ClinicalTrials.gov, number NCT01738035. FINDINGS: Between Dec 11, 2012, and June 25, 2015, 150 randomised patients were treated (safety set) and 149 patients were eligible for the full analysis set. Overall, at 9 months TRF-budesonide (16 mg/day plus 8 mg/day) was associated with a 24·4% (SEM 7·7%) decrease from baseline in mean UPCR (change in UPCR vs placebo 0·74; 95% CI 0·59-0·94; p=0·0066). At 9 months, mean UPCR had decreased by 27·3% in 48 patients who received 16 mg/day (0·71; 0·53-0·94; p=0·0092) and 21·5% in the 51 patients who received 8 mg/day (0·76; 0·58-1·01; p=0·0290); 50 patients who received placebo had an increase in mean UPCR of 2·7%. The effect was sustained throughout followup. Incidence of adverse events was similar in all groups (43 [88%] of 49 in the TRF-budesonide 16 mg/day group, 48 [94%] of 51 in the TRF-budesonide 8 mg/day, and 42 [84%] of 50 controls). Two of 13 serious adverse events were possibly associated with TRF-budesonide-deep vein thrombosis (16 mg/day) and unexplained deterioration in renal function in follow-up (patients were tapered from 16 mg/day to 8 mg/day over 2 weeks and follow-up was assessed 4 weeks later). INTERPRETATION: TRF-budesonide 16 mg/day, added to optimised RAS blockade, reduced proteinuria in patients with IgA nephropathy. This effect is indicative of a reduced risk of future progression to end-stage renal disease. TRF-budesonide could become the first specific treatment for IgA nephropathy targeting intestinal mucosal immunity upstream of disease manifestation. FUNDING: Pharmalink AB.

Prevention of cardiovascular disease in adult recipients of kidney transplants.

Although advances in immunosuppression, tissue typing, surgery, and medical management have made transplantation a routine and preferred treatment for patients with irreversible renal failure, successful transplant recipients have a greatly increased risk of premature mortality because of cardiovascular disease and malignancy compared with the general population. Conventional cardiovascular risk factors such as hyperlipidaemia, hypertension, and diabetes are common in transplant recipients, partly because of the effects of immunosuppressive drugs, and are associated with adverse outcomes. However, the natural history of cardiovascular disease in such recipients differs from that in the general population, and only statin therapy has been studied in a large-scale interventional trial. Thus, the management of this disease and the balance between management of conventional risk factors and modification of immunosuppression is complex.

Rosuvastatin in diabetic hemodialysis patients.

A randomized, placebo-controlled trial in diabetic patients receiving hemodialysis showed no effect of atorvastatin on a composite cardiovascular endpoint, but analysis of the component cardiac endpoints suggested that atorvastatin may significantly reduce risk. Because the AURORA (A Study to Evaluate the Use of Rosuvastatin in Subjects on Regular Hemodialysis: An Assessment of Survival and Cardiovascular Events) trial included patients with and without diabetes, we conducted a post hoc analysis to determine whether rosuvastatin might reduce the risk of cardiac events in diabetic patients receiving hemodialysis. Among the 731 participants with diabetes, traditional risk factors such as LDL-C, smoking, and BP did not associate with cardiac events (cardiac death and nonfatal myocardial infarction). At baseline, only age and high-sensitivity C-reactive protein were independent risk factors for cardiac events. Assignment to rosuvastatin associated with a nonsignificant 16.2% reduction in risk for the AURORA trial's composite primary endpoint of cardiac death, nonfatal MI, or fatal or nonfatal stroke (HR 0.84; 95% CI 0.65 to 1.07). There was no difference in overall stroke, but the rosuvastatin group had more hemorrhagic strokes than the placebo group (12 versus two strokes, respectively; HR, 5.21; 95% CI 1.17 to 23.27). Rosuvastatin treatment significantly reduced the rates of cardiac events by 32% among patients with diabetes (HR 0.68; 95% CI 0.51 to 0.90). In conclusion, among hemodialysis patients with diabetes mellitus, rosuvastatin might reduce the risk of fatal and nonfatal cardiac events.

Cardiovascular disease in renal transplant recipients.

Renal transplant recipients have a markedly increased risk of premature cardiovascular disease (CVD) compared with the general population, although considerably lower than that of patients receiving maintenance haemodialysis. CVD in transplant recipients is poorly characterised and differs from the nonrenal population, with a much higher proportion of fatal to nonfatal cardiac events. In addition to traditional ischaemic heart disease risk factors such as age, gender, diabetes and smoking, there are additional factors to consider in this population such as the importance of hypertension, left ventricular hypertrophy and uraemic cardiomyopathy. There are factors specific to transplantation such immunosuppressive therapies and graft dysfunction which contribute to this altered risk profile. However, understanding and treatment is limited by the absence of large randomised intervention trials addressing risk factor modification, with the exception of the ALERT study. The approach to managing these patients should begin early and be multifactorial in nature.