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.)

BackgroundAKI is common among hospitalized patients with coronavirus disease 2019 (COVID-19) and is an independent risk factor for mortality. Although there are numerous potential mechanisms underlying COVID-19–associated AKI, our current knowledge of kidney pathologic findings in COVID-19 is limited.MethodsWe examined the postmortem kidneys from 42 patients who died of COVID-19. We reviewed light microscopy findings in all autopsies and performed immunofluorescence, electron microscopy, and in situ hybridization studies for SARS-CoV-2 on a subset of samples.ResultsThe cohort had a median age of 71.5 years (range, 38–97 years); 69% were men, 57% were Hispanic, and 73% had a history of hypertension. Among patients with available data, AKI developed in 31 of 33 patients (94%), including 6 with AKI stage 1, 9 with stage 2, and 16 with stage 3. The predominant finding correlating with AKI was acute tubular injury. However, the degree of acute tubular injury was often less severe than predicted for the degree of AKI, suggesting a role for hemodynamic factors, such as aggressive fluid management. Background changes of hypertensive arterionephrosclerosis and diabetic glomerulosclerosis were frequent but typically mild. We identified focal kidney fibrin thrombi in 6 of 42 (14%) autopsies. A single Black patient had collapsing FSGS. Immunofluorescence and electron microscopy were largely unrevealing, and in situ hybridization for SARS-CoV-2 showed no definitive positivity.ConclusionsAmong a cohort of 42 patients dying with COVID-19, autopsy histologic evaluation revealed acute tubular injury, which was typically mild relative to the degree of creatinine elevation. These findings suggest potential for reversibility upon resolution of SARS-CoV-2 infection.

Background National guidelines disagree on who should be screened for undiagnosed diabetes. No existing diabetes risk score is highly generalizable or widely followed. Objectives To develop a new diabetes screening score and compare it to other available screening instruments (Centers for Disease Control and Prevention, American Diabetes Association (ADA) and U.S. Preventive Services Task Force guidelines; two ADA risk questionnaires; and Rotterdam model) Design Cross-sectional data. Setting National Health and Nutrition Examination Survey (NHANES) 1999–2004 for model development, and NHANES 2005–2006 plus a combined cohort of two community studies, Atherosclerosis Risk in Communities (ARIC) and Cardiovascular Health Study (CHS), for validation. Participants U.S. adults ≥20 years old. Measurements A risk scoring algorithm for undiagnosed diabetes, defined as fasting plasma glucose ≥7.0 mmol/L(126 mg/dL) without known diabetes, was developed in the development dataset. Logistic regression was used to determine participant characteristics that were independently associated with undiagnosed diabetes. The new algorithm and other methods were evaluated by standard diagnostic and feasibility measures. Results Age, sex, family history of diabetes, history of hypertension, obesity, and physical activity were associated with undiagnosed diabetes. In NHANES (in ARIC/CHS), the cutpoint of ≥5 selected 30(40)% of persons for diabetes screening and yielded sensitivity of 79(72)%, specificity of 67(62)%, positive predictive value of 10(10)% and likelihood ratio-positive of 2.39(1.89). In contrast, the comparison scores yielded sensitivity of 44–100%, specificity of 10–73%, positive predictive value of 5–8%, and likelihood ratio-positive of 1.11–1.98. Limitations Data during pregnancy were not available. Conclusions This new diabetes screening score, simple and easily implemented, seems to demonstrate improvements upon the existing methods. Future studies are needed to evaluate it in diverse populations in real world settings. Primary Funding Source Clinical and Translational Science Center at Cornell Medical College.

Interruption of the renin-angiotensin-aldosterone system has become a leading therapeutic strategy in the treatment of chronic heart and kidney disease. Angiotensin-converting-enzyme inhibitors and angiotensin-receptor blockers do not, however, uniformly suppress the renin-angiotensin-aldosterone system. Plasma aldosterone levels are elevated in a subset of patients despite therapy. This phenomenon, known as 'aldosterone escape' or 'aldosterone breakthrough', has only been directly examined in small numbers of patients. The key questions of how often breakthrough occurs and whether breakthrough leads to worse outcomes have yet to be definitively answered. In this Review, we summarize the reported data on the incidence and clinical implications of aldosterone breakthrough, and highlight areas of uncertainty that have yet to be adequately addressed in the literature. Although the available evidence is not strong enough to support widespread screening for aldosterone breakthrough, our findings should prompt physicians to consider the phenomenon in select patients as well as guide future research efforts.

SummaryBackground and objectives Renal biopsies performed in diabetic patients are increasing in number and complexity. This study sought to determine the usefulness of renal biopsy in patients with diabetes and the predictability of diagnosing diabetic nephropathy (DN) versus nondiabetic renal disease (NDRD) from clinical and laboratory data.Design, setting, participants, & measurements To assess modern trends, a retrospective study was performed of clinical-pathologic findings in all patients with diabetes who had a biopsy in 2011. Among 2642 native kidney biopsies, 620 (23.5%) were from patients with diabetes.Results The cohort included 371 men (60.7%) aged a median (interquartile range) 62 years (52-69) with 10-year (5-15) duration of diabetes mellitus (DM). Median serum creatinine was 2.5 mg/dl (1.6-4.4), and 52% of patients had stage 4-5 CKD. On biopsy, 37% of patients had DN alone, 36% had NDRD alone, and 27% had DN plus NDRD. In NDRD alone, FSGS (22%), hypertensive nephrosclerosis (18%), acute tubular necrosis (ATN) (17%), IgA nephropathy (11%), membranous GN (8%), and pauci-immune GN (7%) comprised 80% of diagnoses, compared with ATN (43%), hypertensive nephrosclerosis (19%), FSGS (13%), and IgA nephropathy (7%) for DN plus NDRD. In multivariate analyses, longer duration of DM was associated with a greater likelihood of DN and a lower likelihood of NDRD: each added year of DM reduced the odds of NDRD by 5% (odds ratio, 0.95; 95% confidence interval, 0.91 to 0.98; P=0.004). DM duration $12 years was the best predictor (58% sensitivity, 73% specificity) of DN alone.Conclusions Approximately one-quarter of all renal biopsies are performed in patients with DM. Judicious use of renal biopsy has uncovered NDRD alone or superimposed on DN in the majority of such biopsies. ATN is emerging as an important category of NDRD, which has not been reported previously.