Predictive factors of progression of chronic renal insufficiency: a multivariate analysis

Epidemiology of pediatric chronic kidney disease/kidney failure: learning from registries and cohort studies

Although the concept of chronic kidney disease (CKD) in children is similar to that in adults, pediatric CKD has some peculiarities, and there is less evidence and many factors that are not clearly understood. The past decade has witnessed several additional registry and cohort studies of pediatric CKD and kidney failure. The most common underlying disease in pediatric CKD and kidney failure is congenital anomalies of the kidney and urinary tract (CAKUT), which is one of the major characteristics of CKD in children. The incidence/prevalence of CKD in children varies worldwide. Hypertension and proteinuria are independent risk factors for CKD progression; other factors that may affect CKD progression are primary disease, age, sex, racial/genetic factors, urological problems, low birth weight, and social background. Many studies based on registry data revealed that the risk factors for mortality among children with kidney failure who are receiving kidney replacement therapy are younger age, female sex, non-White race, non-CAKUT etiologies, anemia, hypoalbuminemia, and high estimated glomerular filtration rate at dialysis initiation. The evidence has contributed to clinical practice. The results of these registry-based studies are expected to lead to new improvements in pediatric CKD care.

Multidisciplinary Chronic Kidney Disease Clinic Practices: A Scoping Review

BACKGROUND

Multidisciplinary chronic kidney disease (CKD) clinics improve patient outcomes but their optimal design is unclear.

OBJECTIVE

To perform a scoping review to identify and describe current practices (structure, function) associated with multidisciplinary CKD clinics.

DESIGN

Scoping review.

SETTING

Databases included Medline, EMBASE, Cochrane, and CINAHL.

PATIENTS

Patients followed in multidisciplinary CKD clinics globally.

MEASUREMENTS

Multidisciplinary CKD clinic composition, entry criteria, follow-up, and outcomes.

METHODS

We systematically searched the literature to identify randomized controlled trials, non-randomized interventional studies, or observational studies of multidisciplinary CKD clinics defined by an outpatient setting where two or more allied health members (with or without a nephrologist) provided longitudinal care to 50 or more adult or pediatric patients with CKD. Included studies were from 2002 to present. Searches were completed on August 10, 2018. Title, abstracts, and full texts were screened independently by two reviewers with disagreements resolved by a third. We abstracted data from included studies to summarize multidisciplinary CKD clinic team composition, entry criteria, follow-up, and processes.

RESULTS

40 studies (8 randomized controlled trials and 32 non-randomized interventional studies or observational studies) involving 23 230 individuals receiving multidisciplinary CKD care in 12 countries were included. Thirty-eight focused on adults (27 with CKD, 10 incident dialysis patients, one conservative therapy) while two studies focused on adolescents or children with CKD. The multidisciplinary team included a mean of 4.6 (SD 1.5) members consisting of a nephrologist, nurse, dietician, social worker, and pharmacist in 97.4%, 86.8%, 84.2%, 57.9%, and 42.1% of studies respectively. Entry criteria to multidisciplinary CKD clinics ranged from glomerular filtration rates of 20 to 70 mL/min/1.73m2 or CKD stages 1 to 5 without any proteinuria or risk equation-based criteria. Frequency of follow-up was variable by severity of kidney disease. Team member roles and standardized operating procedures were infrequently reported.

LIMITATIONS

Unstandardized definition of multidisciplinary CKD care, studies limited to CKD defined by glomerular filtration rate, and lack of representation from countries other than Canada, Taiwan, the United States, and the United Kingdom.

CONCLUSIONS

There is heterogeneity in multidisciplinary CKD team composition, entry criteria, follow-up, and processes with inadequate reporting of this complex intervention. Additional research is needed to determine the best model for multidisciplinary CKD clinics.

TRIAL REGISTRATION

Not applicable.

Anthropometric and biochemical profile of children and adolescents with chronic kidney disease in a predialysis pediatric interdisciplinary program

This is longitudinal retrospective observational cohort study that evaluated anthropometric and biochemical variables of children and adolescents admitted to a Predialysis Interdisciplinary Management Program (PDIMP) responsible for the follow-up of children and adolescents at stages 2 to 4 of chronic kidney disease (CKD) at a tertiary center. One hundred thirty-eight patients with CKD on predialysis treatment with median age at admission of 9 years and the median follow-up time of 5 years were evaluated. Seventy-four (53%) had CKD stage 3 at admission and 70 (51%) reached CKD stage 5 at the end of the follow-up. There was no significant difference between the mean initial and final hemoglobin and serum albumin. However, the final serum bicarbonate presented a significant improvement. Analyses stratified according to clinical variables of interest showed a significant improvement in body mass index (BMI) Z score, especially in the subgroup of children admitted under two years of age. In relation to stature-for-age Z score, data show a significant improvement in stature SD at the end of the study. In conclusion, the present study showed improvement of nutritional status of CKD patients and that the deterioration of renal function was not correlated with BMI-for-age Z score.

A predictive model of progression of CKD to ESRD in a predialysis pediatric interdisciplinary program

BACKGROUND AND OBJECTIVES

The incidence of ESRD in children has increased over the last two decades. Nevertheless, there are still limited data on risk factors related to the emergence of ESRD among patients with CKD. The aim of this study was to develop a model of prediction of ESRD in children and adolescents with CKD (stages 2-4) enrolled in a predialysis interdisciplinary management program.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this retrospective cohort study, 147 patients with CKD admitted from 1990 to 2008 were systematically followed up at a tertiary pediatric nephrology unit for a median of about 4.5 years. The primary outcome was the progression to CKD stage 5. A predictive model was developed using Cox proportional hazards model and evaluated by c statistics.

RESULTS

The median renal survival was estimated at 98.7 months (95% confidence interval [95% CI], 68.7 to 129.6 months). The probability of reaching CKD stage 5 was estimated as 52% in 10 years. The most accurate model included eGFR, proteinuria at admission, and primary renal disease. Risk score ranged from 0 to 13 points (median, 4 points). The accuracy of the score applied to the sample was high, with c statistics of 0.865 (95% CI, 0.80 to 0.93) and 0.837 (95% CI, 0.76 to 0.91) at follow-up of 2 and 5 years, respectively. By survival analysis, it was estimated that at 10 years after admission, the probability of renal survival was about 63% for patients in the low-risk group and 43% for the medium-risk group; all patients assigned to the high-risk group had CKD stage 5 (P<0.001).

CONCLUSION

The predictive model of progression of CKD might contribute to early identification of a subgroup of patients at high risk for accelerated renal failure.

Early risk factors for neonatal mortality in CAKUT: analysis of 524 affected newborns

BACKGROUND

Congenital abnormalities of the kidney and urinary tract (CAKUT) are significant causes of morbidity. The aim of the study was to determine predictive factors of mortality in newborns with CAKUT.

METHODS

All 29,653 consecutive newborns hospitalized in a tertiary neonatal unit between 1996 and 2006 were evaluated. The main outcome was neonatal mortality. The variables analyzed as risk factors were maternal age, first pregnancy, low birth weight (LBW), prematurity, oligohydramnios, and CAKUT associated with other malformations (Associated CAKUT).

RESULTS

CAKUT was detected in 524 newborns, with an overall prevalence of 17.7 per 1,000 live births. A total of 325 (62%) cases were classified as urinary tract dilatation, 79 (15.1%) as renal cystic disease, and 120 (22.9%) as other subgroups. In the urinary tract dilatation subgroup, independent risk factors for early mortality were Associated CAKUT [odds ratio (OR) 20.7], prematurity (OR 4.5) LBW (OR 3.8), oligohydramnios (OR 3.0), and renal involvement (OR 3.0). In the renal cystic disease subgroup, two variables remained associated with neonatal mortality: LBW (OR 12.3) and Associated CAKUT (OR 21.4).

CONCLUSION

The presence of extrarenal anomalies was a strong predictor of poor outcome in a larger series of infants with CAKUT.

Clinical course of 822 children with prenatally detected nephrouropathies

BACKGROUND AND OBJECTIVES

With the advent of fetal screening ultrasonography, the detection of congenital anomalies of the kidney and urinary tract (CAKUT) in utero has permitted early management of these conditions. This study aims to describe the clinical course of a large cohort of patients with prenatally detected nephrouropathies.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In this retrospective cohort study, 822 patients were prenatally diagnosed with CAKUT and systematically followed up at a tertiary Renal Unit for a median time of 43 months. Variables included in the analysis were sex, laterality, fetal ultrasonography (isolated versus associated hydronephrosis), and presence/absence of nephrouropathies. The events of interest were urinary tract infection, surgical interventions, hypertension, CKD, and death. Survival analyses were performed to evaluate time until occurrence of the events of interest.

RESULTS

Urinary tract infection occurred in 245 (29.8%) children, with higher risk in females (hazard ratio=1.30, 95% confidence interval=1.02-1.70, P=0.05); 22 patients (2.7%) had hypertension, and 49 (6%) patients developed CKD. The risk of CKD was greater in patients with associated hydronephrosis (hazard ratio=5.20, 95% confidence interval=2.90-9.30, P<0.001). Twelve patients (1.5%) died during follow-up. Death was significantly associated with being born during the first period of the study (hazard ratio=6.00, 95% confidence interval=1.60-22.50, P<0.001), associated hydronephrosis (hazard ratio=9.30, 95% confidence interval=2.90-29.30, P<0.001), and CKD (hazard ratio=170.00, 95% confidence interval=41.00-228.00, P<0.001).

CONCLUSIONS

In our series, the clinical course of prenatally detected CAKUT was heterogeneous, and those infants with associated hydronephrosis at baseline were identified as a high-risk subgroup.

Behavioral disorders and low quality of life in children and adolescents with chronic kidney disease

Recent years has seen an increasing interest in the quality of life (QOL) of children with chronic kidney disease (CKD). The objective of this cross-sectional study was to investigate the prevalence of behavioral disorders and to assess the health-related QOL (HRQOL) in 136 patients with CKD. To estimate the prevalence of behavior disorders and analyze HRQOL, we used the Strengths and Difficulties Questionnaire (SDQ) and Pediatric Inventory of Quality of Life (PedsQL) Core Scales as assessment tools for both the patients and caregivers. When compared to healthy controls, the CKD group had significantly lower scores in almost all PedsQL domains. After adjustment, only absence of religion/other religions remained significantly associated with a lower global HRQOL score [odds ratio (OR) 6.2, P=0.009]. Among the parents, two factors remained significantly associated with a lower global HRQOL score: patients' age >10 years (OR 5.4, P=0.033) and absence of religion/other religions (OR 3.2, P=0.038). The CKD group demonstrated a higher proportion of behavioral and emotional disorders in all SDQ domains. There was a negative correlation between the presence of behavior and emotional disorders and HRQOL score (r= -0.552, P<0.001). Our findings suggest the importance of evaluating behavioral and social repercussions of CKD in order to improve the life quality of this pediatric population.

Risk factors for progression of chronic kidney disease

PURPOSE OF REVIEW

The present review provides an overview of the identified risk factors for chronic kidney disease (CKD) progression emphasizing the pediatric population.

RECENT FINDINGS

Over the past 10 years, there have been significant changes to our understanding and study of preterminal kidney failure. Recent refinements in the measurement of glomerular filtration rate and glomerular filtration rate estimating equations are important tools for identification and association of risk factors for CKD progression in children. In pediatric CKD, lower level of kidney function at presentation, higher levels of proteinuria, and hypertension are known markers for a more rapid decline in glomerular filtration rate. Anemia and other reported risk factors from the pregenomic era require further study and validation. Genome-wide association studies have identified genetic loci that have provided novel genetic risk factors for CKD progression.

SUMMARY

With cohort studies of children with CKD becoming mature, they have started to yield important refinements to the assessment of CKD progression. Although many of the traditional risk factors for renal progression will certainly be assessed, such cohorts will be important for evaluating novel risk factors identified by genome-wide studies.

What do we know about chronic renal failure in young adults? II. Adult outcome of pediatric renal disease

Congenital abnormalities of the kidney and urinary tract (CAKUT) account for more than half of all renal failure in children. For young adults with CAKUT two questions are paramount: what is the prognosis and what is the best management to improve outcome? The paediatric literature shows that prognostic factors are glomerular filtration rate (GFR) and the presence of proteinuria. We reviewed data from 101 young adult patients with either primary vesico-ureteric reflux and renal dysplasia or obstructive uropathy. Patients had an estimated GFR (eGFR) of <or=60 ml/min per 1.73 m(2) body surface area and had had at least 5 years of follow up (median 162 months). There was a strong correlation between the amount of proteinuria at the start and overall rate of decline. Angiotensin-converting enzyme inhibitors (ACEIs) slowed declining renal function at all levels of function, but this only had a significant effect on renal outcome when eGFR was >35 ml/min. The ACEI benefit increased with time. Rate of decline was slower than reported for other diseases and was only -2.4 ml/min per year for those reaching the start of dialysis. Outcome is predictable by the level of residual renal function (GFR). Nevertheless, function remains stable while proteinuria is minimal. Short-term studies overestimate rates of deterioration.

Clinical outcome of children with chronic kidney disease in a pre-dialysis interdisciplinary program

The purpose of this retrospective cohort study was to describe the outcome of 107 patients with chronic kidney disease (CKD) admitted to a pre-dialysis interdisciplinary management program from 1990 to 2006. The events of interest were progression to CKD stage 5 (renal survival), patient survival, hypertension, and somatic growth. Survival was studied by the Kaplan-Meier method. Patients were classified into four groups according to their primary renal disease: congenital nephro-uropathies; glomerular diseases; cystic disease, and miscellaneous. Median follow-up time was 94 months [Interquartile (IQ) range 38-145]. The probability of reaching CKD stage 5 was estimated to be 36% by 5 years after admission. As a whole, the mean estimated glomerular filtration rate (GFR) decrease per year was 5.8 ml/min per 1.73 m(2) body surface area [standard deviation (SD) 12.4]. The glomerular diseases group showed a median rate of GFR deterioration of 10 ml/min per 1.73 m(2) per year (IQ range -24 to -5.7), whereas the median rate of GFR deterioration for the groups with cystic diseases, congenital nephro-uropathies, and miscellanea were 2.5 ml/min (IQ range -10 to +0.34), 2.2 ml/min (IQ range -5.0 to -0.52), and 0.36 ml/min (IQ range -2.5 to +2.6), respectively (P < 0.001). The results of this study support the view that children and adolescents with glomerular diseases present a faster deterioration of renal function. Therefore, patients with glomerular diseases need to be referred early to a pediatric nephrology center so that suboptimal pre-dialysis care might possibly be avoided.

Systemic hypertension and proteinuria in childhood chronic renal parenchymal disease: role of antihypertensive drug management

A variety of chronic kidney diseases tend to progress towards end-stage kidney disease. Progression is largely due to factors unrelated to the initial disease, including systemic hypertension and proteinuria. Drugs that block the renin-angiotensin II-aldosterone system, either ACE inhibitors or angiotensin II receptor antagonists, reduce both BP and proteinuria and appear superior to a more conventional antihypertensive treatment regimen in preventing progression to end-stage kidney disease. The most recent recommendations state that the BP goal in children with chronic kidney disease is the corresponding 90th centile for body height, age, and gender. Since satisfactory BP control is often not achieved, the mnemonic acronym DELTAREPROSI was generated to recall the following tips for the practical management of hypertension and proteinuria in childhood chronic renal parenchymal disease: DEfinition of hypertension and Low blood pressure TArget in REnal disease (90th centile calculated by means of simple formulas), potential of drugs inhibiting the REnin-angiotensin II-aldosterone system in hypertension and PROteinuria, advantages of SImplified treatment regimens and escalating the doses every SIx weeks.

Genetic polymorphisms of the RAS-cytokine pathway and chronic kidney disease

Chronic kidney disease (CKD) in children is irreversible. It is associated with renal failure progression and atherosclerotic cardiovascular (CV) abnormalities. Nearly 60% of children with CKD are affected since birth with congenital or inherited kidney disorders. Preliminary evidence primarily from adult CKD studies indicates common genetic risk factors for CKD and atherosclerotic CV disease. Although multiple physiologic pathways share common genes for CKD and CV disease, substantial evidence supports our attention to the renin angiotensin system (RAS) and the interlinked inflammatory cascade because they modulate the progressions of renal and CV disease. Gene polymorphisms in the RAS-cytokine pathway, through altered gene expression of inflammatory cytokines, are potential factors that modulate the rate of CKD progression and CV abnormalities in patients with CKD. For studying such hypotheses, the cooperative efforts among scientific groups and the availability of robust and affordable technologies to genotype thousands of single nucleotide polymorphisms (SNPs) across the genome make genome-wide association studies an attractive paradigm for studying polygenic diseases such as CKD. Although attractive, such studies should be interpreted carefully, with a fundamental understanding of their potential weaknesses. Nevertheless, whole-genome association studies for diabetic nephropathy and future studies pertaining to other types of CKD will offer further insight for the development of targeted interventions to treat CKD and associated atherosclerotic CV abnormalities in the pediatric CKD population.

Progression of chronic renal failure in children with dysplastic kidneys

The aim of this study is to describe progression of chronic renal failure (CRF) in children with renal malformations and to study factors influencing this progression. We reviewed retrospectively 176 children with CRF secondary to renal dysplasia, reflux nephropathy or renal obstruction with at least 5 years of follow-up. Serum creatinine was recorded at least every third month, and an estimated glomerular filtration rate (eGFR) was calculated. Number of febrile urinary tract infections (UTI), blood pressure, albuminuria (UaUc), and number of functioning kidneys was also recorded. We found that the development of renal function could be separated into three time periods: (1) During the first years of life, 82% of the children showed early improvement of their kidney function, which lasted until a median age of 3.2 years (median improvement 6.3 ml/year). (2) From the age of 3.2 years until 11.4 years, 52.5% of the studied children showed a stable kidney function, whereas in 47.5%, kidney function immediately started to deteriorate. (3) Around puberty, 42.9% started deterioration in kidney function, whereas 57.1% even after puberty showed a stable function. Patients with UaUc >200 mg/mmol deteriorated faster (-6.5 ml/min per 1.73 m(2) per year compared with -1.5 ml/min per 1.73 m(2) per year) in those with UaUc <50 mg/mmol. Children with more than two febrile UTIs, hypertension or an eGFR at onset of less than 40 ml/min per 1.73 m(2) deteriorated faster than the others. Most children experienced early improvement of kidney function. The further prognosis, early or late deterioration of kidney function or stable function during the whole follow-up, was related to albuminuria, number of febrile UTIs, eGFR at onset of deterioration, hypertension and puberty.

Anomalies of the kidney and urinary tract are common in de Lange syndrome

Sixty-one patients affected by de Lange syndrome underwent a careful renal and urological evaluation including family and personal history, physical examination, urinalysis, renal tract ultrasonography, and serum creatinine. A voiding cystourethrography was performed in patients with urinary tract infections, in patients with renal ectopy, and in patients with small kidneys. Structural anomalies of the kidney and urinary tract were detected either by ultrasound or voiding cystourethrography in 25 patients (41%): absent or poor corticomedullary differentiation (N = 8; 13%), pelvic dilation (N = 6; 10%), vesicoureteral reflux (N = 5; 8%), small kidney (N = 3; 5%), isolated renal cyst (N = 3; 5%), and renal ectopia (N = 2; 3%). Renal function was normal in 52 patients (85%) but reduced in 9 patients (15%) with renal tract abnormalities. Overt proteinuria was disclosed in three patients with impaired renal function.

Risk factors for renal failure in children with non-glomerular nephropathies

The aim of the present study was to analyze the progression of chronic renal failure (CRF), the effects of modification of risk factors for disease progression, and to formulate a theoretical model of CRF progression in an unselected group of children with CRF. The study was a cross-sectional, retrospective analysis of 92 patients aged 9.2+/-5.8 years with CRF and low-level proteinuria [glomerular filtration rate (GFR) 43+/-18 ml/min per 1.73 m(2), proteinuria 0.57 g/day, range 0-3.9 g/day]. Inclusion criteria were an established diagnosis of CRF and completion of any surgical treatment. The etiology of CRF in the majority of patients was congenital uropathy. Sixty-nine patients observed for longer than 3 years were divided into two groups according to progression of CRF or improvement of GFR. Forty-three patients were on renoprotective therapy. Over a 3-year period GFR decreased in 39 children and improved in 30 children. There were no differences between the groups in the etiology of CRF. Patients with progression of CRF were older ( P<0.08), grew faster ( P<0.004), had higher blood pressure ( P<0.01), and were more often proteinuric ( P<0.03). Arterial hypertension in patients with progression of CRF was resistant to therapy and these patients needed more intensive treatment. Renoprotective therapy led to improvement of kidney function in 50% of patients, and resistance to renoprotective therapy was correlated with increased body mass and height. Patients who received renoprotective drugs showed stabilized kidney function ( P<0.007) and decreased proteinuria ( P<0.05) and blood pressure ( P<0.02), despite higher basal values. In patients on renoprotective therapy in whom CRF progressed despite treatment, proteinuria was persistent in contrast to patients with improvement ( P<0.02). The best model of CRF progression in the path diagram included systolic blood pressure and anthropometric parameters. In conclusion, in unselected patients with CRF of non-glomerular origin and nil-to-moderate proteinuria the main risk factors for CRF progression are rapid somatic growth, age, and blood pressure. Arterial hypertension and proteinuria, even of mild intensity, differ significantly between patients with progression of CRF and those with stable or improved renal function. Renoprotective therapy is related to significant slowing of CRF progression, but the risk factors for resistance to therapy include persistent proteinuria and somatic growth.