The Phenotypic Spectrum of COL4A3 Heterozygotes

Introduction

The penetrance and phenotypic spectrum of autosomal dominant Alport Syndrome (ADAS), affecting 1 in 106, remains understudied.

Methods

Using data from 174,418 participants in the Geisinger MyCode/DiscovEHR study, an unselected health system-based cohort with whole exome sequencing, we identified 403 participants who were heterozygous for likely pathogenic COL4A3 variants. Phenotypic data was evaluated using International Classification of Diseases (ICD) codes, laboratory data, and chart review. To evaluate the phenotypic spectrum of genetically-determined ADAS, we matched COL4A3 heterozygotes 1:5 to nonheterozygotes using propensity scores by demographics, hypertension, diabetes, and nephrolithiasis.

Results

COL4A3 heterozygotes were at significantly increased risks of hematuria, decreased estimated glomerular filtration rate (eGFR), albuminuria, and kidney failure (P < 0.05 for all comparisons) but not bilateral sensorineural hearing loss (P = 0.9). Phenotypic severity was more severe for collagenous domain glycine missense variants than protein truncating variants (PTVs). For example, patients with Gly695Arg (n = 161) had markedly increased risk of dipstick hematuria (odds ratio [OR] 9.50; 95% confidence interval [CI]: 6.32, 14.28) and kidney failure (OR 7.02; 95% CI: 3.48, 14.16) whereas those with PTVs (n = 119) had moderately increased risks of dipstick hematuria (OR 1.64; 95% CI: 1.03, 2.59) and kidney failure (OR 3.44; 95% CI: 1.28, 9.22). Less than a third of patients had albuminuria screening completed, and fewer than 1 of 3 were taking inhibitors of the renin-angiotensin-aldosterone system.

Conclusion

This study demonstrates a wide spectrum of phenotypic severity in ADAS due to COL4A3 with phenotypic variability by genotype. Future studies are needed to evaluate the impact of earlier diagnosis, appropriate evaluation, and treatment of ADAS.

The Phenotypic Spectrum of COL4A3 Heterozygotes

Most data on Alport Syndrome (AS) due to COL4A3 are limited to families with autosomal recessive AS or severe manifestations such as focal segmental glomerulosclerosis (FSGS). Using data from 174,418 participants in the Geisinger MyCode/DiscovEHR study, an unselected health system-based cohort with whole exome sequencing, we identified 403 participants (0.2%) who were heterozygous for likely pathogenic COL4A3 variants. Phenotypic data was evaluated using International Classification of Diseases (ICD) codes, laboratory data, and chart review. To evaluate the phenotypic spectrum of genetically-determined autosomal dominant AS, we matched COL4A3 heterozygotes 1:5 to non-heterozygotes using propensity scores by demographics, hypertension, diabetes, and nephrolithiasis. COL4A3 heterozygotes were at significantly increased risks of hematuria, decreased estimated glomerular filtration rate (eGFR), albuminuria, and end-stage kidney disease (ESKD) (p<0.05 for all comparisons) but not bilateral sensorineural hearing loss (p=0.9). Phenotypic severity tended to be more severe among patients with glycine missense variants located within the collagenous domain. For example, patients with Gly695Arg (n=161) had markedly increased risk of dipstick hematuria (OR 9.47, 95% CI: 6.30, 14.22) and ESKD diagnosis (OR 7.01, 95% CI: 3.48, 14.12) whereas those with PTVs (n=119) had moderately increased risks of dipstick hematuria (OR 1.63, 95% CI: 1.03, 2.58) and ESKD diagnosis (OR 3.43, 95% CI: 1.28, 9.19). Less than a third of patients had albuminuria screening completed, and fewer than 1/3 were taking inhibitors of the renin-angiotensin-aldosterone system (RAASi). Future studies are needed to evaluate the impact of earlier diagnosis, appropriate evaluation, and treatment of ADAS.

Integrated Digital Health System Tools to Support Decision Making and Treatment Preparation in CKD: The PREPARE NOW Study

Rationale & Objective

Digital health system tools to support shared decision making and preparation for kidney replacement treatments for patients with chronic kidney disease (CKD) are needed.

Study Design

Descriptive study of the implementation of digital infrastructure to support a patient-centered health system intervention.

Setting & Participants

4 CKD clinics within a large integrated health system.

Exposure

We developed an integrated suite of digital engagement tools to support patients’ shared decision making and preparation for kidney failure treatments. Tools included an automated CKD patient registry and risk prediction algorithm within the electronic health record (EHR) to identify and prioritize patients in need of nurse case management to facilitate shared decision making and preparation for kidney replacement treatments, an electronic patient-facing values clarification tool, a tracking application to document patients’ preparation for treatments, and an EHR work flow to broadcast patients’ treatment preferences to all health care providers.

Outcomes

Uptake and acceptability.

Analytic Approach

Mixed methods.

Results

From July 1, 2017, through June 30, 2018, the CKD registry identified 1,032 patients in 4 nephrology clinics, of whom 243 (24%) were identified as high risk for progressing to kidney failure within 2 years. Kidney Transitions Specialists enrolled 117 (48%) high-risk patients by the end of year 1. The values tool was completed by 30/33 (91%) patients who attended kidney modality education. Nurse case managers used the tracking application for 100% of patients to document 287 planning steps for kidney replacement therapy. Most (87%) high-risk patients had their preferred kidney replacement modality documented and displayed in the EHR. Nurse case managers reported that the tools facilitated their identification of patients needing support and their navigation activities.

Limitations

Single institution, short duration.

Conclusions

Digital health system tools facilitated rapid identification of patients needing shared and informed decision making and their preparation for kidney replacement treatments.

Funding

This work was supported through a Patient-Centered Outcomes Research Institute (PCORI) Project Program Award (IHS-1409-20967).

Trial registration

ClinicalTrials.gov NCT02722382.

Putting patients at the center of kidney care transitions: PREPARE NOW, a cluster randomized controlled trial

Care for patients transitioning from chronic kidney disease to kidney failure often falls short of meeting patients' needs. The PREPARE NOW study is a cluster randomized controlled trial studying the effectiveness of a pragmatic health system intervention, 'Patient Centered Kidney Transition Care,' a multi-component health system intervention designed to improve patients' preparation for kidney failure treatment. Patient-Centered Kidney Transition Care provides a suite of new electronic health information tools (including a disease registry and risk prediction tools) to help providers recognize patients in need of Kidney Transitions Care and focus their attention on patients' values and treatment preferences. Patient-Centered Kidney Transition Care also adds a 'Kidney Transitions Specialist' to the nephrology health care team to facilitate patients' self-management empowerment, shared-decision making, psychosocial support, care navigation, and health care team communication. The PREPARE NOW study is conducted among eight [8] outpatient nephrology clinics at Geisinger, a large integrated health system in rural Pennsylvania. Four randomly selected nephrology clinics employ the Patient Centered Kidney Transitions Care intervention while four clinics employ usual nephrology care. To assess intervention effectiveness, patient reported, biomedical, and health system outcomes are collected annually over a period of 36 months via telephone questionnaires and electronic health records. The PREPARE NOW Study may provide needed evidence on the effectiveness of patient-centered health system interventions to improve nephrology patients' experiences, capabilities, and clinical outcomes, and it will guide the implementation of similar interventions elsewhere.

TRIAL REGISTRATION

NCT02722382.

Bisphosphonates and mortality in women with CKD and the presence or absence of cardiovascular disease

BACKGROUND AND OBJECTIVES

A modest protective association between bisphosphonate prescription and mortality among women with CKD but without clinically manifest cardiovascular disease has been shown. Whether a prior cardiovascular event (myocardial infarction, stroke, or heart failure) modifies this association is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A cohort of adult women with stages 3 and 4 CKD receiving primary care in a rural integrated health care system during the period 2004-2011 without history of advanced malignancy or organ transplantation (n=6756, median age=74 years, median follow-up=4.3 years) was retrospectively assembled. The primary analysis compared those patients prescribed bisphosphonates (both prevalent and incident use during follow-up) with those patients not prescribed. Additional approaches were taken to account for survival and indication biases. The primary outcome was time to death by Cox multivariable regression.

RESULTS

In the primary analysis, compared with women not prescribed a bisphosphonate, the hazard ratio (95% confidence interval) for death among women prescribed a bisphosphonate was 0.90 (0.78 to 1.04) if there was no history of cardiovascular event but 1.22 (1.04 to 1.42) if there was history of cardiovascular event (P for interaction=0.004). In the additional approaches, associations between bisphosphonate prescription and mortality among those patients with a prior cardiovascular history varied: hazard ratios (95% confidence intervals) were 1.25 (1.01 to 1.57), 1.48 (1.16 to 1.88), and 0.94 (0.66 to 1.34). Interaction by prior cardiovascular event history varied across these three approaches (P=0.07, P=0.22, and P=0.05).

CONCLUSION

In this study of women with CKD, the association between bisphosphonate treatment and mortality risk was inconclusive across a series of analyses designed to account for various types of selection and indication bias.

Variability in estimated glomerular filtration rate is an independent risk factor for death among patients with stage 3 chronic kidney disease

Associations between variability of glomerular filtration rate (GFR), death, and cardiovascular events have not been reported among patients with chronic kidney disease (CKD). In order to evaluate this, we retrospectively analyzed the risk of death and de novo heart failure as a function of variability in estimated GFR among a cohort of 3361 patients with stage 3 CKD. At baseline, patients with greater variability were younger, more likely to have diabetes, hypertension, and other comorbid conditions, and were more likely to have proteinuria and higher estimated GFR. In multivariate-adjusted Cox proportional hazard models over a median follow-up of 3.9 years, the risk of death associated with the highest relative to the lowest quartile of variability was 1.40 (95% confidence interval 1.05-1.87); there was no association with new-onset heart failure. The mortality association was independent of serum albumin, proteinuria, baseline estimated GFR, and the slope of the estimated GFR. Thus, variability in estimated GFR predicts death among patients with stage 3 CKD independent of previously reported risk factors. The prognostic utility of complementing existing risk stratification metrics with dynamic changes in GFR among patients with CKD warrants investigation.

Bisphosphonate therapy, death, and cardiovascular events among female patients with CKD: a retrospective cohort study

BACKGROUND

Accelerated vascular calcification contributes to cardiovascular disease burden in patients with chronic kidney disease (CKD). We hypothesized that bisphosphonate therapy would reduce the risk of mortality and cardiovascular events in this population.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Adult women with stage 3 or 4 CKD receiving primary care in a large rural integrated health care system in 2004-2010.

EXPOSURE

Time-dependent exposure status based on outpatient prescription for any medication within the bisphosphonate class, obtained from electronic health records.

OUTCOMES

Time to death and first cardiovascular event (composite of myocardial infarction, heart failure, or stroke).

RESULTS

Data from 9,604 eligible female patients with CKD were analyzed; 3,234 were treated with bisphosphonate therapy. During a median follow-up of 3.9 (25th-75th percentile, 2.3-5.4) years, there were 286 versus 881 deaths and 206 versus 571 cardiovascular events (treated vs not-treated groups, respectively). In a multivariate Cox proportional hazard model, the adjusted HR for death (treated vs not treated) was 0.78 (95% CI, 0.67-0.91; P = 0.003). In Cox modeling adjusted for similar baseline covariates, treatment with bisphosphonates was not associated with a lower risk of the composite cardiovascular outcome (adjusted HR, 1.14; 95% CI, 0.94-1.39; P = 0.2).

LIMITATIONS

Residual confounding by unidentified factors, exclusion of male patients, and lack of information about longitudinal drug adherence.

CONCLUSIONS

For female patients with CKD, treatment with bisphosphonates is associated with a lower risk of death, but not cardiovascular events. Confirmatory studies and investigations of potential causal mechanisms are warranted.

Fat-free weight prediction in morbidly obese females

Purpose

Precise estimation of creatinine clearance in obese individuals relies on the appropriate assessment of lean body weight (LBW). Anthropometric methods of predicting LBW have not been validated in morbidly obese populations.

Patients and methods

Using an existing dataset of anthropometric data for a female cohort with morbid obesity who had undergone measured FFW with dual energy absorptiometry, we evaluated the performance of five previously reported estimating equations for the prediction of LBW. Linear regression was used to derive a new LBW prediction formula and was then compared with the other formulae.

Results

Seventy females (mean [standard deviation] age, weight, and body mass index 43.0 [11.0] years, 128.1 [13.8] kg, and 48.3 [4.8] kg/m², respectively) were identified. LBW as estimated by the method of Garrow and Webster correlated well (r = 0.87) with measured mass while demonstrating the highest accuracy, best precision, and smallest bias (93%, 2.1 kg, and 2.9 kg, respectively; P < 0.0001 for all comparisons). The derived formula further improved bias, precision, and accuracy.

Conclusion

Among females with morbid obesity, most previously reported estimating equations for LBW predicted FFW poorly. These findings have important clinical implications for the assessment of kidney function and for safe and effective drug dosing.

GFR decline and mortality risk among patients with chronic kidney disease

BACKGROUND AND OBJECTIVES

Estimates of the effect of estimated GFR (eGFR) decline on mortality have focused on populations with normal kidney function, or have included limited information on factors previously shown to influence the risk of death among patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We retrospectively assessed the effect of rate of eGFR decline on survival of patients with CKD receiving primary care through a large integrated health care system in central Pennsylvania between January 1, 2004, and December 31, 2009.

RESULTS

A total of 15,465 patients were followed for a median of 3.4 years. Median rates of eGFR change by those in the lower, middle, and upper tertiles of eGFR slope were -4.8, -0.6, and 3.5 ml/min per 1.73 m(2)/yr, respectively. In Cox proportional hazard modeling for time to death, adjusted for baseline proteinuria, changes in nutritional parameters, and episodes of acute kidney injury during follow-up (among other covariates), the hazard ratio for those in the lower (declining) and upper (increasing) eGFR tertiles (relative to the middle, or stable, tertile) was 1.84 and 1.42, respectively. Longitudinal changes in nutritional status as well as episodes of acute kidney injury attenuated the risk only modestly. These findings were consistent across subgroups.

CONCLUSIONS

eGFR change over time adds prognostic information to traditional mortality risk predictors among patients with CKD. The utility of incorporating eGFR trends into patient-risk assessment should be further investigated.

Remitting seronegative symmetrical synovitis with pitting edema syndrome in a rural tertiary care practice: a retrospective analysis

OBJECTIVE

To review the clinical and laboratory features of remitting seronegative symmetrical synovitis with pitting edema (RS3PE) in a rural tertiary care rheumatology practice, describe treatments and outcomes, and compare our results to previous reports in the literature.

PATIENTS AND METHODS

We performed a retrospective chart review of all patients diagnosed as having RS3PE who were seen in the Department of Rheumatology at Geisinger Medical Center, Danville, PA, from January 1, 1992, to December 31, 2005.

RESULTS

We identified 12 men and 2 women, all of whom were white. Mean +/- SD age was 74.0 +/- 6.6 years; mean +/- SD erythrocyte sedimentation rate was 35.9 +/- 21.1 mm/h at presentation. Onset of illness was sudden in 9 patients and insidious in 5. All patients were initially treated with prednisone (15-20 mg/d). Although the response in all was excellent, 9 patients received disease-modifying antirheumatic drugs, either because of ongoing disease activity or in an effort to decrease the use of corticosteroids. Hydroxychloroquine was used alone in 7 patients. At the mean +/- SD time of last follow-up (31.4 +/- 23.1 months), 5 patients continued to receive therapy. Complications of treatment included worsening of preexisting hypertension in 3 patients, gastritis in 2, and exacerbation of preexisting diabetes mellitus in 1. Carpal tunnel syndrome occurred in 6 patients. Duration of therapy ranged from 5 to 120 months (mean, 29 months). Three patients developed malignancies, ie, non-Hodgkin lymphoma, transitional cell carcinoma of the bladder, and prostate carcinoma.

CONCLUSION

Our population of patients with RS3PE is similar to those documented in previous reports: elderly, predominantly male, and responsive to corticosteroids. However, our series is clinically differentiated by a greater use of adjunctive disease-modifying antirheumatic drugs (primarily hydroxychloroquine). Confirming previous reports, we also observed a possible association between RS3PE and malignancy.

Outpatient erythropoietin administered through a protocol-driven, pharmacist-managed program may produce significant patient and economic benefits

To assess the effect of a disease management program in anemia of chronic kidney disease (CKD), the authors reviewedthe records of all adults treated with epoetin alfa (EPO) at their institution between September 2003 and April 2006 and compared them with a group treated through a pharmacist-managed program with patients managed by PCPs in terms of time to target hemoglobin (Hb) (11-12.9 mg/dL), percent of Hb values maintained in target range, average weekly dose of EPO, and percent of iron-saturation (T-sat) values within target range (20%-50%) over a period of six months to one year. Although pharmacist-managed patients received lower weekly EPO doses than those managed by PCPs (6,698 vs. 12,000 units, respectively; P = .0001), they achieved goal Hb faster (47.5 vs. 62.5 days, P = .11) and maintained a higher percentage of Hb and T-sat values in target range (69.8% vs. 43.9%, P = .0001, and 64.8% (vs. 40.4%, respectively; P = .043). A pharmacist-managed program may present significant clinicaland economic benefits in anemia of CKD.