Genotype-first analysis in an unselected health system-based population reveals variable phenotypic severity of COL4A5 variants.

Introduction: Our knowledge of X-linked Alport Syndrome [AS] comes mostly from selected cohorts with more severe disease. Methods: We examined the phenotypic spectrum of X-linked AS in males and females with a genotype-based approach using data from the Geisinger MyCode DiscovEHR study, an unselected health system-based cohort with exome sequencing and electronic health record data. Patients with COL4A5 variants reported as pathogenic (P) or likely pathogenic (LP) in ClinVar, or protein-truncating variants (PTVs), were each matched with up to 5 controls without COL4A3/4/5 variants by sociodemographics, diabetes diagnosis, and year of first outpatient encounter. AS-related phenotypes included dipstick hematuria, bilateral sensorineural hearing loss (BSHL), proteinuria, decreased eGFR, and ESKD. Results: Out of 170,856 patients, there were 30 hemizygous males (mean age 52.4 [SD 19.8] years) and 56 heterozygous females (mean age 58.5 [SD 19.4]) with a COL4A5 P/LP variant, including 48 with the hypomorphic variant p.Gly624Asp. Overall, penetrance (having any AS phenotypic feature) was highest for non-p.Gly624Asp P/LP variants (males: 89%, females: 86%), intermediate for p.Gly624Asp (males: 77%, females: 69%), compared to controls (males: 32%; females: 50%). The proportion with ESKD was highest for males with P/LP variants (41%), intermediate for males with p.Gly624Asp (15%) and females with P/LP variants (10%), compared to controls (males: 3%, females 2%). Only 33% of males and 11% of females had a known diagnosis of Alport syndrome or thin basement membrane disease. Only 47% of individuals with COL4A5 had completed albuminuria screening, and a minority were taking renin-angiotensin aldosterone system (RAAS) inhibitors. Conclusion: In an unselected cohort, we show increased risks of AS-related phenotypes in men and women compared to matched controls, while showing a wider spectrum of severity than has been described previously and variability by genotype. Future studies are needed to determine whether early genetic diagnosis can improve outcomes in Alport Syndrome.

Preferences for and Experiences of Shared and Informed Decision Making Among Patients Choosing Kidney Replacement Therapies in Nephrology Care.

RATIONALE & OBJECTIVE: Chronic kidney disease (CKD) can progress rapidly, and patients are often unprepared to make kidney failure treatment decisions. We aimed to better understand patients' preferences for and experiences of shared and informed decision making (SDM) regarding kidney replacement therapy before kidney failure. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: Adults receiving nephrology care at CKD clinics in rural Pennsylvania. PREDICTORS: Estimated glomerular filtration rate, 2-year risk for kidney failure, duration and frequency of nephrology care, and preference for SDM. OUTCOMES: Occurrence and extent of kidney replacement therapy discussions and participants' satisfaction with those discussions. ANALYTIC APPROACH: Multivariable logistic regression to quantify associations between participants' characteristics and whether they had discussions. RESULTS: The 447 study participants had a median age of 72 (IQR, 64-80) years and mean estimated glomerular filtration rate of 33 (SD, 12) mL/min/1.73 m2. Most (96%) were White, high school educated (67%), and retired (65%). Most (72%) participants preferred a shared approach to kidney treatment decision making, and only 35% discussed dialysis or transplantation with their kidney teams. Participants who had discussions (n = 158) were often completely satisfied (63%) but infrequently discussed potential treatment-related impacts on their lives. In multivariable analyses, those with a high risk for kidney failure within 2 years (OR, 3.24 [95% CI, 1.72-6.11]; P < 0.01), longer-term nephrology care (OR, 1.12 [95% CI, 1.05-1.20] per 1 additional year; P < 0.01), and more nephrology visits in the prior 2 years (OR, 1.34 [95% CI, 1.20-1.51] per 1 additional visit; P < 0.01) had higher odds of having discussed dialysis or transplantation. LIMITATIONS: Single health system study. CONCLUSIONS: Most patients preferred sharing CKD treatment decisions with their providers, but treatment discussions were infrequent and often did not address key treatment impacts. Longitudinal nephrology care and frequent visits may help ensure that patients have optimal SDM experiences.

Advanced CKD Care and Decision Making: Which Health Care Professionals Do Patients Rely on for CKD Treatment and Advice?

RATIONALE & OBJECTIVE: Chronic kidney disease (CKD) care is often fragmented across multiple health care providers. It is unclear whether patients rely mostly on their nephrologists or non-nephrologist providers for medical care, including CKD treatment and advice. STUDY DESIGN: Cross-sectional study. SETTING & PARTICIPANTS: Adults receiving nephrology care at CKD clinics in Pennsylvania. PREDICTORS: Frequency, duration, and patient-centeredness (range, 1 [least] to 4 [most]) of participants' nephrology care. OUTCOME: Participants' reliance on nephrologists, primary care providers, or other specialists for medical care, including CKD treatment and advice. ANALYTICAL APPROACH: Multivariable logistic regression to quantify associations between participants' reliance on their nephrologists (vs other providers) and their demographics, comorbid conditions, kidney function, and nephrology care. RESULTS: Among 1,412 patients in clinics targeted for the study, 676 (48%) participated. Among these, 453 (67%) were eligible for this analysis. Mean age was 71 (SD, 12) years, 59% were women, 97% were white, and 65% were retired. Participants were in nephrology care for a median of 3.8 (IQR, 2.0-6.6) years and completed a median of 4 (IQR, 3-5) nephrology appointments in the past 2 years. Half (56%) the participants relied primarily on their nephrologists, while 23% relied on primary care providers, 18% relied on all providers equally, and 3% relied on other specialists. Participants' adjusted odds of relying on their nephrologists were higher for those in nephrology care for longer (OR, 1.08 [95% CI, 1.02-1.15]; P = 0.02), those who completed more nephrology visits in the previous 2 years (OR, 1.16 [95% CI, 1.05-1.29]; P = 0.005), and those who perceived their last interaction with their nephrologists as more patient-centered (OR, 2.63 [95% CI, 1.70-4.09]; P < 0.001). LIMITATIONS: Single health system study. CONCLUSIONS: Many nephrology patients relied on non-nephrologist providers for medical care. Longitudinal patient-centered nephrology care may encourage more patients to follow nephrologists' recommendations.

Risk Factors and Outcomes of Rapid Correction of Severe Hyponatremia.

BACKGROUND AND OBJECTIVES: Rapid correction of severe hyponatremia can result in serious neurologic complications, including osmotic demyelination. Few data exist on incidence and risk factors of rapid correction or osmotic demyelination. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In a retrospective cohort of 1490 patients admitted with serum sodium <120 mEq/L to seven hospitals in the Geisinger Health System from 2001 to 2017, we examined the incidence and risk factors of rapid correction and osmotic demyelination. Rapid correction was defined as serum sodium increase of >8 mEq/L at 24 hours. Osmotic demyelination was determined by manual chart review of all available brain magnetic resonance imaging reports. RESULTS: Mean age was 66 years old (SD=15), 55% were women, and 67% had prior hyponatremia (last outpatient sodium <135 mEq/L). Median change in serum sodium at 24 hours was 6.8 mEq/L (interquartile range, 3.4-10.2), and 606 patients (41%) had rapid correction at 24 hours. Younger age, being a woman, schizophrenia, lower Charlson comorbidity index, lower presentation serum sodium, and urine sodium <30 mEq/L were associated with greater risk of rapid correction. Prior hyponatremia, outpatient aldosterone antagonist use, and treatment at an academic center were associated with lower risk of rapid correction. A total of 295 (20%) patients underwent brain magnetic resonance imaging on or after admission, with nine (0.6%) patients showing radiologic evidence of osmotic demyelination. Eight (0.5%) patients had incident osmotic demyelination, of whom five (63%) had beer potomania, five (63%) had hypokalemia, and seven (88%) had sodium increase >8 mEq/L over a 24-hour period before magnetic resonance imaging. Five patients with osmotic demyelination had apparent neurologic recovery. CONCLUSIONS: Among patients presenting with severe hyponatremia, rapid correction occurred in 41%; nearly all patients with incident osmotic demyelination had a documented episode of rapid correction. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2018_06_05_CJASNPodcast_18_7_G.mp3.

Sequential episodes of ethylene glycol poisoning in the same person.

Ethylene glycol is a common alcohol found in many household products such as household hard surface cleaner, paints, varnish, auto glass cleaner and antifreeze. While extremely toxic and often fatal on ingestion, few cases with early presentation by the patient have resulted in death; thus, rapid diagnosis is paramount to effectively treating ethylene glycol poisoning. In this study, we compare two sequential cases of ethylene glycol poisoning in a single individual, which resulted in strikingly different outcomes.

Hypernatremia in a patient treated with sodium polystyrene sulfonate.

Severe hyperkalemia requires urgent medical attention and correction in order to prevent arrhythmic complications. Sodium polystyrene sulfonate (SPS) is a cation exchange resin commonly used in the management of hyperkalemia. A recent review raised concerns regarding its effectiveness and potential adverse effects. Hypernatremia in adults in the setting of sodium polystyrene sulfonate therapy has not been described in the literature. We report the case of a woman who developed hypernatremia in the setting of excessive SPS administration and hope to increase awareness among clinicians regarding this potential side effect of SPS therapy.