Prematurity and future kidney health: the growing risk of chronic kidney disease

The Mechanism of Hyperoxia-Induced Neonatal Renal Injury and the Possible Protective Effect of Resveratrol

With recent advances in neonatal intensive care, preterm infants are surviving into adulthood. Nonetheless, epidemiological data on the health status of these preterm infants have begun to reveal a worrying theme; prematurity and the supplemental oxygen therapy these infants receive after birth appear to be risk factors for kidney disease in adulthood, affecting their quality of life. As the incidence of chronic kidney disease and the survival time of preterm infants both increase, the management of the hyperoxia-induced renal disease is becoming increasingly relevant to neonatologists. The mechanism of this increased risk is currently unknown, but prematurity itself and hyperoxia exposure after birth may predispose to disease by altering the normal trajectory of kidney maturation. This article reviews altered renal reactivity due to hyperoxia, the possible mechanisms of renal injury due to hyperoxia, and the role of resveratrol in renal injury. KEY POINTS: · Premature infants commonly receive supplementary oxygen.. · Hyperoxia can cause kidney damage via signal pathways.. · We should reduce the occurrence of late sequelae..

Associations Between Prematurity, Birthweight, and Adolescence Blood Pressure in a Nationwide Cohort

Introduction

Prematurity is associated with incomplete nephrogenesis and an increased incidence of acute kidney injury, that may increase the risk of future kidney disease, including hypertension, proteinuria and reduced glomerular filtration rate. The aim of this study was to evaluate the risk of hypertension or proteinuria in adolescents born prematurely or small for gestational age, in a nationwide cohort.

Methods

The study cohort included potential recruits examined in the Israel Defense Forces (IDF) medical facilities, between November 2005 and October 2018. Clinical and anthropometric data, including blood pressure (BP) measurement, were retrieved from the IDF medical files. Adolescents born between January 1993 and December 2000 had additional data on gestational age at birth, retrieved from the Israeli Ministry of Health database.

Results

The study cohort included 513,802 participants, aged 17.3 ± 0.9 years, of whom 48,994 had gestational age data. Adolescents born as very preterm, as extremely preterm infants, those born with very low birthweight (VLBW), or with extremely low birthweight (ELBW) had higher incidence of hypertensive-range BP (55%, 47%, 19% and 12%, respectively). No significant association between birthweight (BW) adjusted to gestational age and hypertension was observed. Within the overweight and obese adolescents, those born with VLBW and ELBW, had further increased hypertensive-range BP rate. Proteinuria was diagnosed in 0.33% of the study cohort, with no significant difference between BW or gestational age categories.

Conclusion

Adolescents born with VLBW or as significant preterm were associated with high BP and should be monitored for hypertension development and its potential complications.

Pre-gestational counselling for women living with CKD: starting from the bright side

Pregnancy in women living with chronic kidney disease (CKD) was often discouraged due to the risk of adverse maternal-fetal outcomes and the progression of kidney disease. This negative attitude has changed in recent years, with greater emphasis on patient empowerment than on the imperative 'non nocere'. Although risks persist, pregnancy outcomes even in advanced CKD have significantly improved, for both the mother and the newborn. Adequate counselling can help to minimize risks and support a more conscious and informed approach to those risks that are unavoidable. Pre-conception counselling enables a woman to plan the most appropriate moment for her to try to become pregnant. Counselling is context sensitive and needs to be discussed also within an ethical framework. Classically, counselling is more focused on risks than on the probability of a successful outcome. 'Positive counselling', highlighting also the chances of a favourable outcome, can help to strengthen the patient-physician relationship, which is a powerful means of optimizing adherence and compliance. Since, due to the heterogeneity of CKD, giving exact figures in single cases is difficult and may even be impossible, a scenario-based approach may help understanding and facing favourable outcomes and adverse events. Pregnancy outcomes modulate the future life of the mother and of her baby; hence the concept of 'post partum' counselling is also introduced, discussing how pregnancy results may modulate the long-term prognosis of the mother and the child and the future pregnancies.

Recent Advances in Kidney Replacement Therapy in Infants: A Review

Kidney replacement therapy (KRT) is used to treat children and adults with acute kidney injury (AKI), fluid overload, kidney failure, inborn errors of metabolism, and severe electrolyte abnormalities. Peritoneal dialysis and extracorporeal hemodialysis/filtration can be performed for different durations (intermittent, prolonged intermittent, and continuous) through either adaptation of adult devices or use of infant-specific devices. Each of these modalities have advantages and disadvantages, and often multiple modalities are used depending on the scenario and patient-specific needs. Traditionally, these therapies have been challenging to deliver in infants due the lack of infant-specific devices, small patient size, required extracorporeal volumes, and the risk of hemodynamic stability during the initiation of KRT. In this review, we discuss challenges, recent advancements, and optimal approaches to provide KRT in hospitalized infants, including a discussion of peritoneal dialysis and extracorporeal therapies. We discuss each specific KRT modality, review newer infant-specific devices, and highlight the benefits and limitations of each modality. We also discuss the ethical implications for the care of infants who need KRT and areas for future research.

Advances and potential of regenerative medicine in pediatric nephrology

The endogenous capacity of the kidney to repair is limited, and generation of new nephrons after injury for adequate function recovery remains a need. Discovery of factors that promote the endogenous regenerative capacity of the injured kidney or generation of transplantable kidney tissue represent promising therapeutic strategies. While several encouraging results are obtained after administration of stem or progenitor cells, stem cell secretome, or extracellular vesicles in experimental kidney injury models, very little data exist in the clinical setting to make conclusions about their efficacy. In this review, we provide an overview of the cutting-edge knowledge on kidney regeneration, including pre-clinical methodologies used to elucidate regenerative pathways and describe the perspectives of regenerative medicine for kidney patients.

Blood Pressure Outcomes in NICU-Admitted Infants with Neonatal Hypertension: A Pediatric Nephrology Research Consortium Study

OBJECTIVE

To describe the blood pressure outcomes of infants admitted to the neonatal intensive care unit (NICU) with idiopathic (nonsecondary) hypertension (HTN) who were discharged on antihypertensive therapy.

STUDY DESIGN

Retrospective, multicenter study of 14 centers within the Pediatric Nephrology Research Consortium. We included all infants with a diagnosis of idiopathic HTN discharged from the NICU on antihypertensive treatment. The primary outcome was time to discontinuation of antihypertensive therapy, grouped into (≤6 months, >6 months to 1 year, and >1 year). Comparisons between groups were made with χ2 tests, Fisher's exact tests, and ANOVA.

RESULTS

Data from 118 infants (66% male) were included. Calcium channel blockers were the most prescribed class of antihypertensives (56%) in the cohort. The percentages remaining on antihypertensives after NICU discharge were 60% at 6 months, 26% at 1 year, and 7% at 2 years. Antenatal steroid treatment was associated with decreased likelihood of antihypertensive therapy >1 year after discharge.

CONCLUSIONS

This multicenter study reports that most infants admitted to the NICU diagnosed with idiopathic HTN will discontinue antihypertensive treatment by 2 years after NICU discharge. These data provide important insights into the outcome of neonatal HTN, but should be confirmed prospectively.

Adults are just big kids: pediatric considerations for adult critical care nephrology

PURPOSE OF REVIEW

In recent years, there has been growing attention to pediatric kidney health, especially pediatric acute kidney injury (AKI). However, there has been limited focus on the role of pediatric AKI on adult kidney health, specifically considerations for the critical care physician.

RECENT FINDINGS

We summarize what is known in the field of pediatric AKI to inform adult medical care including factors throughout the early life course, including perinatal, neonatal, and pediatric exposures that impact survivor care later in adulthood.

SUMMARY

The number of pediatric AKI survivors continues to increase, leading to a higher burden of chronic kidney disease and other long-term co-morbidities later in life. Adult medical providers should consider pediatric history and illnesses to inform the care they provide. Such knowledge may help internists, nephrologists, and intensivists alike to improve risk stratification, including a lower threshold for monitoring for AKI and kidney dysfunction in their patients.

Burden and Risk Factors of Contrast-Associated Acute Kidney Injury in Hospitalized Zambian Children: A Prospective Cohort Study at the University Teaching Hospitals

Background

Contrast-associated acute kidney injury (CAAKI) is defined as acute kidney injury (AKI) occurring within 72 hours of administration of contrast media (CM) and is linked to adverse outcomes including longer hospital stay, increased hospital mortality, and a higher risk of chronic kidney disease in later life. Risk factors for the development of CAAKI in the Zambian pediatric population have not been well studied.

Objectives

The objective of this study was to assess the burden of CAAKI, ascertain its risk factors, and describe short-term outcomes in hospitalized children at the University Teaching Hospitals (UTH) undergoing contrast-enhanced radiological investigations.

Methods

This was a prospective observational study of in-patients undergoing contrast-enhanced radiological procedures, between September 2020 and September 2021. The participants were recruited from the Children's Hospital, the Cancer Diseases Hospital, and the Pediatric Surgical Ward at the University Teaching Hospital in Lusaka, Zambia. The primary outcome variable was occurrence of AKI at 48 hours post CM administration. We used 2 criteria to define CAAKI in our study-the European Society of Urogenital Radiology (ESUR) and the Kidney Disease Improving Global Outcomes (KDIGO) 2012 criteria. Multivariable logistic regression models were formulated to assess for risk factors of CAAKI.

Results

Of the 201 enrolled participants, 123 (61.2%) were male and the median age of the participants was 5 years (interquartile range [IQR] = 3-10). The mean hemoglobin was 103 g/L (standard deviation [SD] = 26), median creatinine was 30.9 µmol/l (IQR = 22.6-43), and the glomerular filtration rate (GFR) was 102.5 mL/min/1.73 m2 (IQR = 76.2-129.4). Forty-six (22.9%) developed CAAKI using the ESUR compared with 4.5% (9/201) using the KDIGO criteria. Independent risk factors of CAAKI were receiving a higher dose of CM (adjusted odds ratio [aOR] = 2.54; 95% confidence interval [CI] = [1.12-5.74]), prematurity (aOR = 4.6; 95% CI = [1.05-16.7]), and a higher eGFR (aOR= 1.01; 95% CI = [1.01-1.02]). Females had higher odds of CAAKI (aOR = 2.48; 95% CI = [1.18-5.18]) when compared with males. One CAAKI participant (2.2%) died; none of the participants who developed CAAKI and survived required dialysis and most of them (90%) were discharged before day 7. Day 7 eGFR results had returned to or near baseline values for those whose creatinine results were available.

Conclusions

Using the ESUR criteria, a significant proportion (22.9%) of children undergoing contrast-enhanced computed tomography (CT) scans at the UTH developed CAAKI. In contrast, using the KDIGO criteria only 4.5% had CAAKI. Being born as a preterm baby, being female, having a higher eGFR at baseline, and receiving a higher dose of CM were found to be independent risk factors for CAAKI development in Zambian children. Most of the cases of CAAKI in children were transient and of little clinical significance as only a minority of patients developing CAAKI required kidney replacement therapy and all resolved by day 7 post administration of CM.

Deletion of NuRD component Mta2 in nephron progenitor cells causes developmentally programmed FSGS

Low nephron endowment at birth is a risk factor for chronic kidney disease. The prevalence of this condition is increasing due to higher survival rates of preterm infants and children with multi- organ birth defect syndromes that affect the kidney and urinary tract. We created a mouse model of congenital low nephron number due to deletion of Mta2 in nephron progenitor cells. Mta2 is a core component of the Nucleosome Remodeling and Deacetylase (NuRD) chromatin remodeling complex. These mice developed albuminuria at 4 weeks of age followed by focal segmental glomerulosclerosis (FSGS) at 8 weeks, with progressive kidney injury and fibrosis. Our studies reveal that altered mitochondrial metabolism in the post-natal period leads to accumulation of neutral lipids in glomeruli at 4 weeks of age followed by reduced mitochondrial oxygen consumption. We found that NuRD cooperated with Zbtb7a/7b to regulate a large number of metabolic genes required for fatty acid oxidation and oxidative phosphorylation. Analysis of human kidney tissue also supported a role for reduced mitochondrial lipid metabolism and ZBTB7A/7B in FSGS and CKD. We propose that an inability to meet the physiological and metabolic demands of post-natal somatic growth of the kidney promotes the transition to CKD in the setting of glomerular hypertrophy due to low nephron endowment.

Development of a Family-Centered Communication Tool for Kidney Health in Premature Infants: Qualitative Focus Group Study Using Human-Centered Design Methodology

BACKGROUND

Premature infants are at increased risk of kidney-related complications, including acute kidney injury (AKI) and chronic kidney disease (CKD). The risk of CKD in prematurely born infants is underrecognized by health care teams and caregivers. Understanding how to communicate the risk of CKD to caregivers is essential for longitudinal clinical follow-up and adherence.

OBJECTIVE

This study aimed to determine family caregiver attitudes toward kidney health and risk communication during a neonatal intensive care admission. We also sought to understand caregiver preferences for the communication of information surrounding the risk of CKD in premature infants.

METHODS

We augmented standard qualitative group sessions with human-centered design methods to assess parent preferences and clinician perspectives. Caregivers recruited had a prematurely born child who spent time in the neonatal intensive care unit at Riley Hospital for Children in Indianapolis, Indiana, and experienced AKI or another kidney complication, which put them at risk for future CKD. We used a variety of specific design methods in these sessions, including card sorting, projective methods, experience mapping, and constructive methods.

RESULTS

A total of 7 clinicians and 8 caregivers participated in 3 group sessions. Caregivers and clinicians readily acknowledged barriers to and drivers of long-term kidney monitoring as well as opportunities for communication of the risk of long-term kidney disease. Caregivers' primary concerns were for both the type and depth of information conveyed as well as the time at which it was communicated. Participants emphasized the importance of collaboration between the hospital care team and the primary care provider. Participant input was synthesized into several prototype concepts and, ultimately, into a rough prototype of a website and an informational flyer.

CONCLUSIONS

Caregivers of premature infants are open to communication about kidney health during their neonatal admission. The next phase of this work will translate caregivers' preferences into family-centered communication tools and test their efficacy in the neonatal intensive care unit.

Proteinuria and Renal Dysfunction Due to Extremely Low Birth Weight in a Patient with Silver-Russell Syndrome

A 36-year-old woman diagnosed with Silver-Russell syndrome during childhood presented to our department after a primary care physician suspected renal dysfunction. At birth, she had an extremely low weight (1210 g), and in childhood, she was diagnosed with Silver-Russell syndrome. At the age of 14 she was found to have proteinuria; however, the condition was never further examined. One month prior to her presentation to our department, the following were noted: 3+ urinary protein, 3.9 urinary protein/creatinine ratio, and 48 mL/min/1.73 m² estimated glomerular filtration rate. Abdominal computed tomography revealed small kidneys difficult to visualize using ultrasound. Therefore, an open renal biopsy was performed. The renal biopsy revealed no significant findings in the glomerulus except glomerular hypertrophy, and the glomerular density in the cortical area was low (0.6/mm²). The patient was diagnosed with oligomeganephronia. Proteinuria and renal dysfunction were likely due to glomerular hyperfiltration resulting from a low nephron count caused by low birth weight. Silver-Russell syndrome is characterized by intrauterine growth retardation and additional developmental disorders after birth. Here, we detected oligomeganephronia following kidney biopsy in a patient with Silver-Russell syndrome. We suspect that a reduced number of nephrons due to low birth weight caused proteinuria and renal dysfunction.

The AGE-RAGE Axis and the Pathophysiology of Multimorbidity in COPD

Chronic obstructive pulmonary disease (COPD) is a disease of the airways and lungs due to an enhanced inflammatory response, commonly caused by cigarette smoking. Patients with COPD are often multimorbid, as they commonly suffer from multiple chronic (inflammatory) conditions. This intensifies the burden of individual diseases, negatively affects quality of life, and complicates disease management. COPD and comorbidities share genetic and lifestyle-related risk factors and pathobiological mechanisms, including chronic inflammation and oxidative stress. The receptor for advanced glycation end products (RAGE) is an important driver of chronic inflammation. Advanced glycation end products (AGEs) are RAGE ligands that accumulate due to aging, inflammation, oxidative stress, and carbohydrate metabolism. AGEs cause further inflammation and oxidative stress through RAGE, but also through RAGE-independent mechanisms. This review describes the complexity of RAGE signaling and the causes of AGE accumulation, followed by a comprehensive overview of alterations reported on AGEs and RAGE in COPD and in important co-morbidities. Furthermore, it describes the mechanisms by which AGEs and RAGE contribute to the pathophysiology of individual disease conditions and how they execute crosstalk between organ systems. A section on therapeutic strategies that target AGEs and RAGE and could alleviate patients from multimorbid conditions using single therapeutics concludes this review.

A new cardiovascular disease risk factor for young adults: Preterm birth

ABSTRACT

Adults born preterm (birth <37 weeks' gestation) have a two-fold increased risk of early cardiovascular mortality. With 10% of the U.S. population born prematurely and perinatal advancements dramatically improving survival rates, millions of survivors are now reaching adulthood. This phenomenon has introduced a whole new population of individuals with a history of preterm birth. Although the prevailing notion has been that preterm birth is a condition confined only to infancy and early childhood, we now know preterm birth is a risk for lifelong chronic health conditions. Despite almost a decade of epidemiological evidence showing increased cardiovascular risk for those born preterm, this has not yet been translated into clinical practice. As a result, clinicians are caring for adults born prematurely without screening and treatment guidelines for this at-risk population and few inquire about birth history during clinical encounters. This brief report presents growing evidence about disrupted cardiogenesis and consequential structural and functional modifications. By asking the question "Were you born preterm?," nurse practitioners can take the first step of increasing their awareness of this at-risk population and mitigate adverse cardiovascular outcomes by using preterm birth as a risk factor when determining health promotion and treatment decisions.

Mesoamerican Endemic Nephropathy (MeN): A Disease Reported in Adults That May Start Since Childhood?

Mesoamerican endemic nephropathy (MeN) is a type of chronic kidney disease (CKD) of uncertain etiology that occurs along the Pacific coast of the southern part of Mexico and Central America. During the past 20 years MeN has become a leading cause of death in the region, clamming close to 50,000 lives, with 40% of these deaths occurring in young people. The cause remains unknown, but most researchers believe in a multifactorial etiology that includes social determinants of poverty. Existing evidence suggests that subclinical kidney injury begins early in life and leads to a higher than expected prevalence of CKD among children in Central America. Access to health services in the region, specifically kidney replacement therapy, remains limited. We proposed a strategy to address the perceived needs and urge coordinated efforts of governments, academic organizations, and international bodies to develop a comprehensive plan of action to mitigate this situation among the vulnerable and economically disadvantaged population.

Consensus-Based Recommendations on Priority Activities to Address Acute Kidney Injury in Children: A Modified Delphi Consensus Statement

IMPORTANCE

Increasing evidence indicates that acute kidney injury (AKI) occurs frequently in children and young adults and is associated with poor short-term and long-term outcomes. Guidance is required to focus efforts related to expansion of pediatric AKI knowledge.

OBJECTIVE

To develop expert-driven pediatric specific recommendations on needed AKI research, education, practice, and advocacy.

EVIDENCE REVIEW

At the 26th Acute Disease Quality Initiative meeting conducted in November 2021 by 47 multiprofessional international experts in general pediatrics, nephrology, and critical care, the panel focused on 6 areas: (1) epidemiology; (2) diagnostics; (3) fluid overload; (4) kidney support therapies; (5) biology, pharmacology, and nutrition; and (6) education and advocacy. An objective scientific review and distillation of literature through September 2021 was performed of (1) epidemiology, (2) risk assessment and diagnosis, (3) fluid assessment, (4) kidney support and extracorporeal therapies, (5) pathobiology, nutrition, and pharmacology, and (6) education and advocacy. Using an established modified Delphi process based on existing data, workgroups derived consensus statements with recommendations.

FINDINGS

The meeting developed 12 consensus statements and 29 research recommendations. Principal suggestions were to address gaps of knowledge by including data from varying socioeconomic groups, broadening definition of AKI phenotypes, adjudicating fluid balance by disease severity, integrating biopathology of child growth and development, and partnering with families and communities in AKI advocacy.

CONCLUSIONS AND RELEVANCE

Existing evidence across observational study supports further efforts to increase knowledge related to AKI in childhood. Significant gaps of knowledge may be addressed by focused efforts.

Prevalence and Risk Factors for Kidney Disease and Elevated BP in 2-Year-Old Children Born Extremely Premature

BACKGROUND AND OBJECTIVES

Extremely low gestational age neonates born <28 weeks gestation are at risk for chronic disease. We sought to describe the prevalence of kidney outcomes by gestational age and determine risk factors for their development.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Recombinant Erythropoietin for Protection of Infant Renal Disease (REPAIReD) study examined kidney outcomes of extremely low gestational age neonates enrolled in the Preterm Epo NeuroProtection Trial (PENUT) study. Kidney function, urine albumin, and BP were measured at 2-year (24±2 months) corrected gestational age. We compared outcomes across gestational age categories and evaluated associations between kidney-related outcomes and neonatal and maternal characteristics. The primary outcome was eGFR <90 ml/min per 1.73 m² (CKD); secondary outcomes were spot urine albumin-creatinine ratio ≥30 mg/g (albuminuria) and either systolic BP or diastolic BP >90th percentile for height, age, and sex.

RESULTS

A total of 832 survived to 2 years, and 565 (68%) had at least one outcome measured. Overall, 297 (53%) had one abnormal kidney outcome; 61 (18%) had an eGFR <90 ml/min per 1.73 m², 155 (36%) had albuminuria, 65 (22%) had elevated systolic BP, and 128 (44%) had elevated diastolic BP. Gestational age (odds ratio, 0.94; 95% confidence interval, 0.89 to 0.99), birth weight z-score (odds ratio, 0.92; 95% confidence interval, 0.85 to 0.98), and prenatal steroids (odds ratio, 1.23; 95% confidence interval, 1.08 to 1.39) were associated with an eGFR <90 ml/min per 1.73 m². An elevated systolic BP was associated with indomethacin use (odds ratio, 1.18; 95% confidence interval, 1.04 to 1.33) and Black race (odds ratio, 1.19; 95% confidence interval, 1.01 to 1.39); elevated diastolic BP was associated with male sex (odds ratio, 1.29; 95% confidence interval, 1.12 to 1.49), severe AKI (odds ratio, 1.24; 95% confidence interval, 1.04 to 1.48), and indomethacin use (odds ratio, 1.16; 95% confidence interval, 1.01 to 1.33).

CONCLUSIONS

Approximately 18% of extremely low gestational age neonates have CKD, 36% have albuminuria, 22% have an elevated systolic BP, and 44% have an elevated diastolic BP at 2 years of age. Gestational age, birthweight z-score, and prenatal steroids were associated with CKD. Male sex, Black race, indomethacin use, and severe AKI were associated with elevated BP.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_07_19_CJN15011121.mp3.

Urine Output Monitoring for the Diagnosis of Early-Onset Acute Kidney Injury in Very Preterm Infants

BACKGROUND AND OBJECTIVES

The current threshold used for oliguria in the definition of neonatal AKI has been empirically defined as 1 ml/kg per hour. Urine output criteria are generally poorly documented, resulting in uncertainty in the most accurate threshold to identify AKI in very preterm infants with known tubular immaturity.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a bicentric study including 473 very preterm infants (24^0/7-29^6/7 weeks of gestation) born between January 2014 and December 2018 with urine output measurements every 3 hours during the first 7 days of life and two serum creatinine measurements during the first 10 days of life. AKI was defined using the neonatal Kidney Disease Improving Global Outcomes (KDIGO) definition. We tested whether higher urine output thresholds (1.5 or 2 ml/kg per hour) in modified AKI definitions may better discriminate neonatal mortality compared with the current definition.

RESULTS

Early-onset AKI was developed by 101 of 473 (21%) very preterm infants. AKI was diagnosed on the basis of urine output criteria alone (no rise in creatinine) for 27 of 101 (27%) participants. Early-onset AKI was associated with higher risk of death before discharge (adjusted odds ratio, 3.9; 95% confidence interval, 1.9 to 7.8), and the AKI neonatal KDIGO score showed good discriminative performance for neonatal mortality, with an area under the receiver operating characteristic (ROC) curve of 0.68 (95% confidence interval, 0.61 to 0.75). Modified AKI definitions that included higher urine output thresholds showed significantly improved discriminative performance, with areas under the ROC curve of 0.73 (95% confidence interval, 0.66 to 0.80) for the 1.5-ml/kg per hour threshold and 0.75 (95% confidence interval, 0.68 to 0.81) for the 2-ml/kg per hour threshold.

CONCLUSIONS

Early-onset AKI was diagnosed on the basis of urine output exclusively for a quarter of the cases. Furthermore, modified AKI definitions that included higher urine output improved the discriminative performance for predicting mortality.

Systemic Hypertension in Infants with Bronchopulmonary Dysplasia

PURPOSE OF REVIEW

Neonatal hypertension is increasingly recognized as improvements in neonatal intensive care have led to increased survival of premature infants. Among infants with bronchopulmonary dysplasia (BPD), the rates of hypertension are much higher than the general neonatal population. However, the etiology and pathophysiology of this increased risk of hypertension in neonates with lung disease remain unclear.

RECENT FINDINGS

Among infants with bronchopulmonary dysplasia, the rates of hypertension are much higher than the general neonatal population. New studies suggest outcomes in neonates with BPD with hypertension are usually good, with resolution of hypertension in most infants with lung disease. Several potential mechanisms of hypertension in this patient population have been recently proposed. This review focuses on the recent epidemiologic data on prevalence of hypertension in neonates with bronchopulmonary dysplasia, reviews the typical clinical course, and discusses available strategies for management of infants with bronchopulmonary dysplasia that develop hypertension.

Improving the identification of acute kidney injury in the neonatal ICU: three centers' experiences

OBJECTIVE

To describe three different standardized approaches to improving neonatal acute kidney injury (AKI) identification and the impact on AKI identification, incidence, and nephrology consultation and referral.

STUDY DESIGN

A retrospective cohort study in three academic NICUs. We compared AKI identification, AKI incidence, nephrology consultation, and nephrology follow-up before and after implantation of local protocols to standardize neonatal AKI identification.

RESULT

Neonatal AKI identification improved in all three NICUs following protocol implementation (26-85%, P < 0.0001). Each center also saw increases in nephrology consultation (15-83%, P < 0.0001) and nephrology follow-up (7-73%, P < 0.0001). AKI incidence decreased significantly (21-12%, P < 0.0001).

CONCLUSION

Multiple strategies can be successfully operationalized to improve neonatal AKI identification. While different in approach, each strategy resulted in increased AKI identification and nephrology involvement. This study emphasizes the importance of local standardized approaches to AKI to improve AKI identification and nephrology involvement in the NICU.

The developmental origins of health and chronic kidney disease: Current status and practices in Japan

The concept of the developmental origins of health and disease (DOHaD) views unfavorable perinatal circumstances as contributing to the development of diseases in later life. It is well known that such unfavorable circumstances play an important role as a risk factor for chronic kidney disease (CKD) in infants born with prematurity. Low birthweight (LBW) is believed to be a potential contributor to CKD in adulthood. Preterm and/or LBW infants are born with incomplete nephrogenesis. As a result, the number of nephrons is low. The poor intrauterine environment also causes epigenetic changes that adversely affect postnatal renal function. After birth, hyperfiltration of individual nephrons due to low nephron numbers causes proteinuria and secondary glomerulosclerosis. Furthermore, the risk of CKD increases as renal damage takes a second hit from exposure to nephrotoxic substances and acquired insults such as acute kidney injury after birth among infants in neonatal intensive care. Meanwhile, unfortunately, recent studies have shown that the number of nephrons in healthy Japanese individuals is approximately two-thirds lower than that in previous reports. This means that Japanese premature infants are clearly at a high risk of developing CKD in later life. Recently, several DOHaD-related CKD studies from Japanese researchers have been reported. Here, we summarize the relevance of CKD in conjunction with DOHaD and review recent studies that have examined the impact of the upward LBW trend in Japan on renal health.

Neonatal nephron loss during active nephrogenesis results in altered expression of renal developmental genes and markers of kidney injury

Preterm neonates are at a high risk for nephron loss under adverse clinical conditions. Renal damage potentially collides with postnatal nephrogenesis. Recent animal studies suggest that nephron loss within this vulnerable phase leads to renal damage later in life. Nephrogenic pathways are commonly reactivated after kidney injury supporting renal regeneration. We hypothesized that nephron loss during nephrogenesis affects renal development, which, in turn, impairs tissue repair after secondary injury. Neonates prior to 36 wk of gestation show an active nephrogenesis. In rats, nephrogenesis is ongoing until day 10 after birth. Mimicking the situation of severe nephron loss during nephrogenesis, male pups were uninephrectomized at day 1 of life (UNXd1). A second group of males was uninephrectomized at postnatal day 14 (UNXd14), after terminated nephrogenesis. Age-matched controls were sham operated. Three days after uninephrectomy transcriptional changes in the right kidney were analyzed by RNA-sequencing, followed by functional pathway analysis. In UNXd1, 1,182 genes were differentially regulated, but only 143 genes showed a regulation both in UNXd1 and UNXd14. The functional groups "renal development" and "kidney injury" were among the most differentially regulated groups and revealed distinctive alterations. Reduced expression of candidate genes concerning renal development (Bmp7, Gdnf, Pdgf-B, Wt1) and injury (nephrin, podocin, Tgf-β1) were detected. The downregulation of Bmp7 and Gdnf persisted until day 28. In UNXd14, Six2 was upregulated and Pax2 was downregulated. We conclude that nephron loss during nephrogenesis affects renal development and induces a specific regulation of genes that might hinder tissue repair after secondary kidney injury.

Compromised maternal nutritional status in early pregnancy and its relation to the birth size in young rural Indian mothers

BACKGROUND

Low birth weight is highly prevalent in rural India. As a chronic undernutrition problem, poor birth outcomes are closely related to various nutritional factors more prominently the poor maternal anthropometry at conception. The purpose of the study was to identify how compromised maternal nutritional status in early pregnancy affects the birth size of rural Indian mothers.

METHODS

It was a prospective observational study on singleton pregnant women (n = 204) from 14 villages in Mulshi Taluka of Pune District, Maharashtra, India. Maternal weight (Wt), height (Ht), body fat percent (BF%), head circumference (HC), and sitting height (SHT) were measured at early pregnancy (< 13 weeks of gestation) and infants' weight and length were measured within 24 h of birth. Groups means were tested using a 't' test while the trend in means was tested using ANOVA.

RESULTS

Mothers were young (21.46 ± 2.09 yrs), thin (46.46 ± 6.1 kg), short (153.39 ± 5.79 cm), and poorly nourished (19.74 ± 2.41 kg/m2). Mean birth weight was low (2655 ± 507 g) and prevalence of LBW and stunting at birth was highest among mothers in the lower tertile of each of the anthropometric indicators. In particular, stunting was significantly higher for mothers in lower tertile compared to higher tertile of Wt (44.6 Vs 64.6%) and was also true for HC (43.7 Vs 60.6%). Risk for LBW and stunting at birth was almost similar and was significant (p < 0.01) for mothers in the lower tertile of Wt, Ht, BMI, SHT, HC, and BF% as compared to those in the higher tertile of these measurements.

CONCLUSION

All the anthropometric indicators of current undernutrition at first trimester as well as that in utero reflected by smaller HC, impose risk for LBW and stunting at birth especially among young rural mothers.

Neonatal acute kidney injury: a case-based approach

Neonatal acute kidney injury (AKI) is increasingly recognized as a common complication in critically ill neonates. Over the last 5-10 years, there have been significant advancements which have improved our understanding and ability to care for neonates with kidney disease. A variety of factors contribute to an increased risk of AKI in neonates, including decreased nephron mass and immature tubular function. Multiple factors complicate the diagnosis of AKI including low glomerular filtration rate at birth and challenges with serum creatinine as a marker of kidney function in newborns. AKI in neonates is often multifactorial, but the cause can be identified with careful diagnostic evaluation. The best approach to treatment in such patients may include diuretic therapies or kidney support therapy. Data for long-term outcomes are limited but suggest an increased risk of chronic kidney disease (CKD) and hypertension in these infants. We use a case-based approach throughout this review to illustrate these concepts and highlight important evidence gaps in the diagnosis and management of neonatal AKI.

Early life factors in relation to albuminuria and estimated glomerular filtration rate based on cystatin C and creatinine in adults from a Swedish population-based cohort study

Background

Early life factors influence the number of nephrons a person starts life with and a consequence of that is believed to be premature kidney ageing. Thus, we aimed to identify early life factors associated with cystatin C and creatinine-based estimated glomerular filtration (eGFR) rate equations and urine -albumin-to-creatinine ratio after a follow-up of 46–67 years.

Methods

The study included 593 Swedish subjects without diabetes mellitus from the Malmo Diet Cancer Cohort. Perinatal data records including birth weight, gestational age, placenta weight and maternal related risk factors were analysed. eGFR was determined by Chronic Kidney Disease Epidemiology (CKD-EPI), the Lund-Malmö revised and Caucasian, Asian, Paediatric, and Adult (CAPA) equations. Postnatal growth phenotypes were defined as low (≤ 0) or high (> 0) birth weight z-score, or low (≤ median) or high (> median) body mass index at 20 years of age.

Results

In women, lower birth weight was associated with lower eGFR (CAPA; CKD-EPI cystatin C). Birth weight z-score predicted adult albuminuria specifically in men (OR 0.75, 95% CI [0.58; 0.96]). Women with high birth weight z-score and low BMI at 20 years had lower eGFR (CAPA; CKD-EPI cystatin C; p = 0.04). Men with high birth weight z-score and high BMI at 20 years had lower risk for albuminuria (OR 0.35, 95% CI [0.12; 0.93]).

Conclusions

Lower birth weight, prematurity and postnatal growth curve have a potential sex- specific effect of early exposure to an adverse environment on lower cystatin C-based eGFR and albuminuria later in life. Cystatin C compared to creatinine -eGFR equations shows a higher ability to detect these findings.

Graphic abstract

Effects of prematurity on long-term renal health: a systematic review

OBJECTIVE

To investigate the literature and determine if prematurity has an impact on long-term adverse kidney outcomes.

DESIGN

Systematic review.

DATA SOURCES

OVID Medline, PubMed, SCOPUS, CINAHL and EMBASE databases were searched for studies relating to the adverse outcomes of prematurity from 1990 to April 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

All articles published between January 1990 and April 2021 that investigated whether premature infants developed long-term adverse renal outcomes were included in this review. Articles must have been human studies and written in English. Case series with less than 20 participants and case studies were excluded.

DATA EXTRACTION AND SYNTHESIS

One reviewer completed the database searches. Article selection was performed independently and in a non-blinded manner by both reviewers. Initial screening was by title and abstract. Full texts of remaining articles were reviewed. Articles for which inclusion was unclear were re-reviewed by both reviewers, and a unanimous decision was taken as to whether they should be included. The Newcastle-Ottawa Scale was used for quality assessment of the included articles.

RESULTS

The literature search yielded 31 human studies, which investigated the short-term and long-term kidney outcomes of prematurity. These studies were conducted in 17 different countries. The most common outcomes measured were blood pressure (BP) and glomerular filtration rate. Other common outcomes measured included kidney size and mass, proteinuria, albuminuria, chronic kidney disease (CKD) and physical parameters such as height, weight and body mass index.

CONCLUSION

Prematurity is likely linked to increased risk of kidney dysfunction and high BP in childhood and into early adulthood. Premature birth conferred a twofold increased risk of CKD and extremely premature birth conferred a threefold increased risk of CKD. However, further larger multicentre studies are needed to draw definitive conclusions on the long-term kidney outcomes of prematurity.

Nephrotoxicity in Neonates

Acute kidney injury (AKI) is classified based on prerenal, intrinsic, and postrenal causes. In the newborn, AKI can occur after an insult during the prenatal, perinatal, or postnatal period. AKI is usually an underrecognized condition and its true incidence is unknown. AKI may result from the administration of a number of different nephrotoxic medications, which are often used concurrently in critically ill neonates, exponentially increasing the risk of renal injury. Drug toxicity may also compromise the formation and development of nephrons, and this is particularly important in preterm infants, who have incomplete nephrogenesis. Little is known about the pharmacokinetics and pharmacodynamics of different medications used in neonates, especially for the most immature infant, and the use of most medications in this population is off label. Strategies to prevent AKI include the avoidance of hypotension, hypovolemia, fluid imbalances, hypoxia, and sepsis as well as judicious use of nephrotoxic medications. Treatment strategies aim to maintain fluids and electrolytic and acid-base homeostasis, along with an adequate nutritional status. Neonates are especially prone to long-term sequelae of AKI and benefit from long-term follow-up. This review summarizes the most relevant aspects of nephrotoxicity in neonates and describes the prevention, treatment, and follow-up of AKI in neonates.

Childhood risk factors for adulthood chronic kidney disease

Chronic kidney disease (CKD) is a major public health challenge, affecting as much as 8 to 18% of the world population. Identifying childhood risk factors for future CKD may help clinicians make early diagnoses and initiation of preventive interventions for CKD and its attendant comorbidities as well as monitoring for complications. The purpose of this review is to describe childhood risk factors that may predict development of overt kidney disease later in life. Currently, there are multiple childhood risk factors associated with future onset and progression of CKD. These risk factors can be grouped into five categories: genetic factors (e.g., monogenic or risk alleles), perinatal factors (e.g., low birth weight and prematurity), childhood kidney diseases (e.g., congenital anomalies, glomerular diseases, and renal cystic ciliopathies), childhood onset of chronic conditions (e.g., cancer, diabetes, hypertension, dyslipidemia, and obesity), and different lifestyle factors (e.g., physical activity, diet, and factors related to socioeconomic status). The available published information suggests that the lifelong risk for CKD can be attributed to multiple factors that appear already during childhood. However, results are conflicting on the effects of childhood physical activity, diet, and dyslipidemia on future renal function. On the other hand, there is consistent evidence to support follow-up of high-risk groups.

Contemporary perspectives in COPD: Patient burden, the role of gender and trajectories of multimorbidity

An individual's experience of COPD is determined by many factors in addition to the pathological features of chronic bronchitis and emphysema and the symptoms that derive directly from them. Multimorbidity is the norm rather than the exception, so most people with COPD are living with a range of other medical problems which can decrease overall quality of life. COPD is caused by the inhalation of noxious particles or gases, in particular tobacco smoke, but also by early life disadvantage impairing lung development and by occupations where inhaled exposures are common (e.g. industrial, farming and cleaning work). Wealthy people are therefore relatively protected from developing COPD and people who do develop the condition may have reduced resources to cope. COPD is also no longer a condition that predominantly affects men. The prevalence of COPD among women has equalled that of men since 2008 in many high-income countries, due to increased exposure to tobacco, and in low-income countries due to biomass fuels. COPD is one of the leading causes of death in women in the USA, and death rates attributed to COPD in women in some countries are predicted to overtake those of men in the next decade. Many factors contribute to this phenomenon, but in addition to socioeconomic and occupational factors, there is increasing evidence of a higher susceptibility of females to smoking and pollutants. Quality of life is also more significantly impaired in women. Although most medications (bronchodilators and inhaled corticosteroids) used to treat COPD demonstrate similar trends for exacerbation prevention and lung function improvement in men and women, this is an understudied area and clinical trials frequently have a preponderance of males. A better understanding of gender-based predictors of efficacy of all therapeutic interventions is crucial for comprehensive patient care. There is an urgent need to recognize the increasing burden of COPD in women and to facilitate global improvements in disease prevention and management in this specific population. Many individuals with COPD follow a trajectory of both lung function decline and also multimorbidity. Unfavourable lung function trajectories throughout life have implications for later development of other chronic diseases. An enhanced understanding of the temporal associations underlying the development of coexisting diseases is a crucial first step in unravelling potential common disease pathways. Lessons can be learned from exploring disease trajectories of other NCD as well as multimorbidity development. Further research will be essential to explain how early life risk factors commonly influence trajectories of COPD and other diseases, how different diseases develop in relation to each other in a temporal way and how this ultimately leads to different multimorbidity patterns in COPD. This review integrates new knowledge and ideas pertaining to three broad themes (i) the overall burden of disease in COPD, (ii) an unappreciated high burden in women and (iii) the contrast of COPD trajectories and different multimorbidity patterns with trajectories of other NCD. The underlying pathology of COPD is largely irreversible, but many factors noted in the review are potentially amenable to intervention. Health and social care systems need to ensure that effective treatment is accessible to all people with the condition. Preventive strategies and treatments that alter the course of disease are crucial, particularly for patients with COPD as one of many problems.

Targeting the Renin-Angiotensin-Aldosterone System to Prevent Hypertension and Kidney Disease of Developmental Origins

The renin-angiotensin-aldosterone system (RAAS) is implicated in hypertension and kidney disease. The developing kidney can be programmed by various early-life insults by so-called renal programming, resulting in hypertension and kidney disease in adulthood. This theory is known as developmental origins of health and disease (DOHaD). Conversely, early RAAS-based interventions could reverse program processes to prevent a disease from occurring by so-called reprogramming. In the current review, we mainly summarize (1) the current knowledge on the RAAS implicated in renal programming; (2) current evidence supporting the connections between the aberrant RAAS and other mechanisms behind renal programming, such as oxidative stress, nitric oxide deficiency, epigenetic regulation, and gut microbiota dysbiosis; and (3) an overview of how RAAS-based reprogramming interventions may prevent hypertension and kidney disease of developmental origins. To accelerate the transition of RAAS-based interventions for prevention of hypertension and kidney disease, an extended comprehension of the RAAS implicated in renal programming is needed, as well as a greater focus on further clinical translation.

Gestational systolic blood pressure trajectories and risk of adverse maternal and perinatal outcomes in Chinese women

Background

Associations between trajectories of systolic blood pressure (SBP) during pregnancy and pregnant outcomes remain unclear and disparate.

Methods

Data of 20,353 mothers without chronic hypertension and who delivered live singletons between January, 2014 and November, 2019, was extracted from Taicang register-based cohort. Based on SBP measured during 10 to 40 weeks of gestation, SBP trajectories were explored using latent class growth mixture model, and their associations with maternal and neonatal outcomes were assessed by logistic regression analyses.

Results

Six heterogeneous SBP trajectories were identified: low delayed-increasing (7.47%), low reverse-increasing (21.88%), low-stable (19.13%), medium-stable (21.64%), medium reverse-increasing (16.47%), and high stable (13.41%) trajectories. The high-stable trajectory had SBP around 125 mmHg in the 10th gestational week, and increased slightly onwards. When compared with the low-stable trajectory, the high-stable trajectory had maximally adjusted odds ratio (95% confidence interval) of 5.28 (2.76–10.10), 1.30 (1.13–1.50), 1.53 (1.12–2.08), 1.32 (1.06–1.65) and 1.64 (1.08–2.48) for gestational hypertension (GH), early-term delivery (ETD), preterm delivery (PTD), small for gestational age and low birth weight (LBW), respectively. Besides, the medium reverse-increasing trajectory showed significantly increased risk of GH and ETD, while the medium-stable trajectory had significantly elevated risk of ETD and PTD. Notably, SBP trajectories slightly but significantly improved risk discrimination of GH, ETD and LBW, over traditional risk factors.

Conclusion

Women with different SBP trajectories were at varied risk of adverse maternal and fetal outcomes. Meanwhile, our study suggested that BP monitoring during pregnancy is necessary, especially for women with high SBP in early pregnancy or upward trajectory.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03599-7.

Is Urinary Netrin-1 a Good Marker of Tubular Damage in Preterm Newborns?

There is a lack of a good marker for early kidney injury in premature newborns. In recent publications, netrin-1 seems to be a promising biomarker of kidney damage in different pathological states. The study aimed to measure the urinary level of netrin-1 depending on gestational age. A prospective study involved 88 newborns (I-60 premature newborns, II-28 healthy term newborns). Additionally, premature babies were divided for 2 groups: IA-28 babies born between 30–34 weeks of gestation and IB-32 born at 35–36 weeks. The median urinary concentration of netrin-1 was: IA-(median, Q1–Q3) 63.65 (56.57–79.92) pg/dL, IB-61.90 (58.84–67.17) pg/dL, and II-60.37 (53.77–68.75) pg/dL, respectively. However urinary netrin-1 normalized by urinary concentration of creatinine were IA-547.9 (360.2–687.5) ng/mg cr., IB-163.64 (119.15–295.96) ng/mg cr., and II-81.37 (56.84–138.58) ng/mg cr., respectively and differ significantly between the examined groups (p = 0.00). The netrin-1/creatinine ratio is increased in premature babies. Further studies examining the potential factors influencing kidney function are necessary to confirm its potential value in the diagnosis of subclinical kidney damage in premature newborns.

Perinatal factors contributing to chronic kidney disease in a cohort of Japanese children with very low birth weight

BACKGROUND

Developmental programming of chronic kidney disease (CKD) in young adults is linked to preterm birth and intrauterine growth restriction (IUGR). Which confers a higher risk of progression to chronic kidney damage in children with very low birth weight (VLBW; born weighing < 1500 g): prematurity or IUGR?

METHODS

This is a national historical cohort study of children with VLBW cared for in perinatal medical centers in Japan. Predictive factors included three latent variables (prematurity, IUGR, stress during neonatal period) and eight observed variables (gestational age, birth weight Z-score, maternal age, duration of treatment with antibiotics and diuretics, maternal smoking, late-onset circulatory collapse, kidney dysfunction) during the perinatal period. The primary endpoint was estimated glomerular filtration rate (eGFR) at age ≥ 3 years. A structural equation model was used to examine the pathologic constitution.

RESULTS

The 446 children with VLBW included 253 boys and 193 girls, of mean age 5.8 ± 2.6 years and mean eGFR 111.7 ml/min/1.73 m² at last encounter. Pathway analyses showed intrauterine malnutrition (β = 0.85) contributed more to chronic kidney damage than stress during the neonatal period (β = - 0.19) and prematurity (β = 0.12), and kidney dysfunction and late-onset circulatory collapse were important observed variables in stress during the neonatal period.

CONCLUSIONS

IUGR was more harmful to future kidneys of VLBW neonates. Neonatal kidney dysfunction and late-onset circulatory collapse were important risk factors for subsequent CKD development. This emphasizes the need for obstetricians to monitor for fetal growth restriction and neonatologists to minimize neonatal stress to prevent CKD in later life.

Are My Pediatric Patients at Increased Risk of Developing Chronic Kidney Disease?

Chronic kidney disease (CKD) is an underrecognized and often undiagnosed cause of morbidity and mortality. Many children and adolescents are at increased risk of developing CKD as they mature and age, secondary to conditions commonly cared for by pediatric health professionals. Prematurity, diabetes mellitus, hypertension, congenital heart disease, sickle cell disease and trait, severe obesity, cancer chemotherapy, other drug toxicities, and systemic situations that may cause acute kidney injury such as sepsis or extracorporeal membrane oxygenation therapy predispose to potential CKD. Clinicians should be aware of these conditions in order to screen for CKD, choose non-nephrotoxic treatments for these children whenever possible, and treat or refer those who have early signs of CKD.

Transcriptomic analysis of the mechanisms of alleviating renal interstitial fibrosis using the traditional Chinese medicine Kangxianling in a rat model

Renal interstitial fibrosis (RIF) is currently recognized as a crucial mechanism of the pathogenesis of chronic kidney disease (CKD). Kangxianling (KXL, anti-fibrin) is a traditional Chinese medicine that has been proven to significantly reduce the levels of ECM deposition and inhibit renal fibrosis. To characterize the mechanisms and drug targets of KXL, we established a RIF rat model and treated the rats with KXL and losartan. Histological analyses validated the establishment of the RIF model and the treatment effect of KXL. Multiple levels of transcriptomic datasets were generated using lncRNA, mRNA and microRNA sequencing of kidney tissues. Functional annotations and pathway analyses were performed to unravel the therapeutic mechanisms. A multi-level transcriptomic regulatory network was built to illustrate the core factors in fibrosis pathogenesis and therapeutic regulation. KXL and losartan significantly reduced the progression of RIF, and a better therapeutic effect was shown with higher concentrations of KXL. According to the cluster analysis results of the RNA-seq data, the normal control (NC) and high concentration of KXL (HK) treatment groups were the closest in terms of differentially expressed genes. The WNT, TGF-β and MAPK pathways were enriched and dominated the pathogenesis and therapy of RIF. miR-15b, miR-21, and miR-6216 were upregulated and miR-107 was downregulated in the fibrosis model. These small RNAs were shown to play critical roles in the regulation of the above fibrosis-related genes and could be inhibited by KXL treatment. Finally, based on the lncRNA datasets, we constructed a mRNA-lncRNA-miRNA coexpression ceRNA network, which identified key regulatory factors in the pathogenesis of kidney fibrosis and therapeutic mechanisms of KXL. Our work revealed the potential mechanism of the Chinese medicine Kangxianling in inhibiting renal interstitial fibrosis and supported the clinical use of KXL in the treatment of kidney fibrosis.

Associations of systolic blood pressure trajectories during pregnancy and risk of adverse perinatal outcomes

This study aimed to explore the association of systolic blood pressure (SBP) trajectories of pregnant women with the risk of adverse outcomes of pregnant women and their fetuses. A register-based cohort of 63,724 pregnant women and their fetuses from January 2013 to December 2017 was investigated. Demographic characteristics, history of disease and family history of disease for pregnant women and perinatal outcomes were recorded, and blood pressure was measured during the whole pregnancy. SBP trajectories were estimated with latent mixture modeling by Proc Traj in SAS using SBP data from the first antenatal care appointment (8-14 weeks), the highest SBP before admission, the admission SBP and the SBP at 2 h postpartum. A censored normal model (CNORM) was considered appropriate, and model fit was assessed using the Bayesian information criterion (BIC). A logistic regression model was used to examine the association between SBP trajectories and the risk of adverse perinatal outcomes. Four distinct SBP trajectory patterns over the pregnancy period were identified and were labeled as low-stable, moderate-stable, high-decreasing and moderate-increasing. Three maternal and three fetal adverse outcomes were selected as the main outcome measures. After adjusting for confounding factors, compared with pregnant women with the low-stable pattern, those with the high-decreasing pattern had a higher risk of developing poor growth outcomes of fetuses, while those with the moderate-increasing pattern had higher risks of developing both adverse maternal and fetal outcomes. Our study results suggest that pregnant women should pay attention to the control of blood pressure throughout pregnancy.

Low Birth Weight, Blood Pressure and Renal Susceptibility

PURPOSE OF THE REVIEW

The purpose of this review is to highlight the clinical significance of increased renal risk that has its origins in fetal life. This review will also discuss the critical need to identify therapeutic interventions for use in a pregnancy complicated by placental dysfunction and intrauterine growth restriction that can mitigate the developmental origins of kidney disease without inflicting additional harm on the developing fetus.

RECENT FINDINGS

A reduction in nephron number is a contributory factor in the pathogenesis of hypertension and kidney disease in low birth weight individuals. Reduced nephron number may heighten susceptibility to a secondary renal insult, and recent studies suggest that perinatal history including birth weight should be considered in the assessment of renal risk in kidney donors. This review highlights current findings related to placental dysfunction, intrauterine growth restriction, increased risk for renal injury and disease, and potential therapeutic interventions.

IL-6/Smad2 signaling mediates acute kidney injury and regeneration in a murine model of neonatal hyperoxia

Prematurity is linked to incomplete nephrogenesis and risk of chronic kidney diseases (CKDs). Oxygen is life-saving in that context but induces injury in numerous organs. Here, we studied the structural and functional impact of hyperoxia on renal injury and its IL-6 dependency. Newborn wild-type (WT) and IL-6 knockout (IL-6^-/-) mice were exposed to 85% O₂ for 28 d, followed by room air until postnatal d (P) 70. Controls were in room air throughout life. At P28, hyperoxia reduced estimated kidney cortex area (KCA) in WT; at P70, KCA was greater, number of glomeruli was fewer, fractional potassium excretion was higher, and glomerular filtration rate was slightly lower than in controls. IL-6^-/- mice were protected from these changes after hyperoxia. Mechanistically, the acute renal injury phase (P28) showed in WT but not in IL-6^-/- mice an activation of IL-6 (signal transducer and activator of transcription 3) and TGF-β [mothers against decapentaplegic homolog (Smad)2] signaling, increased inflammatory markers, disrupted mitochondrial biogenesis, and reduced tubular proliferation. Regenerative phase at P70 was characterized by tubular proliferation in WT but not in IL-6^-/- mice. These data demonstrate that hyperoxia increases the risk of CKD through a novel IL-6-Smad2 axis. The amenability of these pathways to pharmacological approaches may offer new avenues to protect premature infants from CKD.-Mohr, J., Voggel, J., Vohlen, C., Dinger, K., Dafinger, C., Fink, G., Göbel, H., Liebau, M. C., Dötsch, J., Alejandre Alcazar, M. A. IL-6/Smad2 signaling mediates acute kidney injury and regeneration in a murine model of neonatal hyperoxia.