Salt-losing nephrogenic diabetes insipidus caused by fetal exposure to angiotensin receptor blocker

[Clinical monitoring of children with in utero exposure to angiotensin-converting-enzyme inhibitors and angiotensin II receptor blockers]

Angiotensin-converting-enzyme inhibitors and angiotensin II receptor blockers are widely used to reduce high blood pressure or in other conditions such as congestive heart failure and prevention of diabetic nephropathy. To date, no teratogenic effect has been attributed to them, but in the 2nd and 3rd trimesters of pregnancy, their foetotoxicity is broadly documented: transient oligohydramnios or anamnios, associated to possible neonatal anuria and permanent renal damage, which can lead to intrauterine or neonatal death. Long-term effects among children with in utero exposure are poorly known, but the regression of an oligohydramnios might not always be associated with normal renal function after birth or later in life. This justifies seeking the advice of a pediatric nephrologistto consider the most appropriate monitoring for the child at birth and in the following weeks, and possibly beyond, even in case of normal prenatal ultrasound.

Valsartan exposure in pregnancy with resultant anhydramnios and chronic kidney disease in a late preterm infant

In utero exposure to angiotensin II receptor blockers (ARBs) has fetotoxic effects including renal failure, oligohydramnios and lung hypoplasia. We present the case of a 24-year-old woman who presented to the maternity services in the 34th week of her first pregnancy. She was taking valsartan for hypertension. Ultrasound showed a structurally normal fetus with anhydramnios. The patient was admitted and valsartan was discontinued. She had spontaneous preterm delivery at 35 weeks' gestation of a baby girl. The baby's urine output was minimal in the first week of life and she was transferred to a paediatric hospital for specialist nephrology input. At 6 months of age, she requires ongoing nephrology follow-up and she remains on treatment for hypertension and anaemia. This case demonstrates the serious adverse effects resulting from ARB exposure in utero, and highlights the importance of avoiding fetotoxic medications in women of childbearing age.

Long-Term Consequences of Fetal Angiotensin II Receptor Antagonist Exposure

Fetal angiotensin II receptor antagonist exposure is associated with major complications and even death when administered during pregnancy. Neonates frequently require intensive care treatment, and mortality is high. Despite this well-known risk potential, a considerable number of women still receive angiotensin II receptor antagonists during pregnancy to treat arterial hypertension. Although clinical symptoms in the neonatal period are well described, few reports address long-term follow-up after fetal exposure to angiotensin II receptor antagonists. We here report on a patient who was unwittingly exposed to olmesartan medoxomil during pregnancy. After birth, the neonate presented with mild clinical symptoms, mainly affecting the kidneys. However, neurodevelopmental follow-up revealed a delay in motor development with muscular hypotonia and failure to thrive at age 2 years. This case highlights the fact that, despite not causing neurological symptoms in the neonatal period, fetal angiotensin II receptor antagonist exposure during pregnancy might lead to neurodevelopmental impairment in later life.

Pregnancy across the spectrum of chronic kidney disease

Management of the pregnant woman with chronic kidney disease is difficult for both nephrologists and obstetricians. Prepregnancy counselling with respect to risk stratification, optimization of maternal health prior to pregnancy, as well as management of the many potential pregnancy-associated complications in this complex patient population remains challenging due to the paucity of large, well-designed clinical studies. Furthermore, the heterogeneity of disease and the relative infrequency of pregnancy, particularly in more advanced stages of chronic kidney disease, leaves many clinicians feeling ill prepared to manage these pregnancies. As such, counselling is imprecise and management varies substantially across centers. All pregnancies in women with chronic kidney disease can benefit from a collaborative multidisciplinary approach with a team that consists of nephrologists experienced in the management of kidney disease in pregnancy, maternal-fetal medicine specialists, high-risk pregnancy nursing staff, dieticians, and pharmacists. Further access to skilled neonatologists and neonatal intensive care unit support is essential given the risks for preterm delivery in this patient population. The goal of this paper is to highlight some of the data that currently exist in the literature, provide management strategies for the practicing nephrologist at all stages of chronic kidney disease, and explore some of the knowledge gaps where future multinational collaborative research efforts should concentrate to improve pregnancy outcomes in women with kidney disease across the globe.

A Novel Mutation in a Japanese Family with X-linked Alport Syndrome

We herein report a novel mutation in a Japanese family with an X-linked Alport syndrome (AS) mutation in COL4A5. Patient 1 was a 2-year-old Japanese girl. She and her mother (patient 2) had a history of proteinuria and hematuria without renal dysfunction, deafness, or ocular abnormalities. Pathological findings were consistent with AS, and a genetic analysis revealed that both patients had a heterozygous mutation (c.2767G>C) in exon 32. In summary, the identification of mutations and characteristic pathological findings was useful in making a diagnosis of AS. For a close long-term follow-up, the early detection and treatment of women with X-linked AS are important.

Prevalence of Albuminuria in a General Population Cohort of Patients With Established Chronic Heart Failure

BACKGROUND

Numerous studies have reported an association between albuminuria and adverse outcomes in adults with chronic heart failure (CHF). However, the prevalence of albuminuria in adults with established CHF remains unclear.

METHODS AND RESULTS

This study was a cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES) 1999-2012. Adults aged ≥18 years were included, and diagnosis of CHF was based on participant self-report. The primary outcome was the prevalence of microalbuminuria (albumin-to-creatinine ratio 30-300 mg/g) and macroalbuminuria (albumin-to-creatinine ratio >300 mg/g) in adults with CHF. The secondary outcome was the adjusted odds ratio of any albuminuria in adults with and without CHF. During the study period, 37,961 adults did not have CHF and 1,214 adults had CHF. In adults with CHF, 22.1% (95% confidence interval [CI] 19.6%-24.7%) had microalbuminuria and 10.4% (95% CI 8.1%-12.7%) macroalbuminuria. In adjusted analyses, the odds of albuminuria in adults with CHF was 1.89-fold higher (95% CI 1.59-2.26; P < .001) than in adults without CHF.

CONCLUSIONS

Taken together, albuminuria is more common in adults with CHF than in those without CHF, even after adjustment for important demographic and clinical confounders.

Renin Angiotensin System Blocker Fetopathy: A Midwest Pediatric Nephrology Consortium Report

OBJECTIVES

Fetuses continue to be exposed to renin angiotensin system (RAS) blockers despite their known teratogenicity and a black box warning. We hypothesized that fetopathy from in utero exposure to RAS blockers has a broader spectrum of clinical manifestations than described previously and that there are a variety of clinical scenarios leading to such exposures.

STUDY DESIGN

This was a retrospective study performed through the Midwest Pediatric Nephrology Consortium. Cases of RAS blocker fetopathy were identified, with determination of renal and extrarenal manifestations, timing of exposure, and the explanation for the fetal exposure.

RESULTS

Twenty-four cases were identified. RAS blocker exposure after the first trimester was associated with more severe renal manifestations. Chronic dialysis or kidney transplantation was required in 8 of 17 (47%) patients with RAS blocker exposure after the first trimester and 0 of 7 patients with exposure restricted to the first trimester (P = .05). Extrarenal manifestations, some not previously noted in the literature, included central nervous system anomalies (cystic encephalomalacia, cortical blindness, sensorineural hearing loss, arachnoid cysts) and pulmonary complications (pneumothorax, pneumomediastinum). RAS blocker exposure usually was secondary to absent or poor prenatal care or undiagnosed pregnancy.

CONCLUSION

RAS blocker fetopathy continues to be a cause of considerable morbidity, with more severe renal manifestations associated with exposure after the first trimester. A variety of significant extrarenal manifestations occur in these patients. Clinicians should emphasize the risk of fetopathy when prescribing RAS blockers to women of childbearing age.

Postnatal acute renal failure after fetal exposure to angiotensin receptor blockers

Maternal hypertensive treatment with angiotensin receptor blockers (ARBs) during the second and third trimester of pregnancy is associated with several fetal and neonatal complications, and potential adverse outcomes. We report a neonate presenting with transient renal acute failure during the first days of life after maternal treatment with ARBs. Women who became pregnant while taking one of these drugs must modify antihypertensive therapy with a different class drug as soon as pregnancy is recognised.

Renal function in angiotensinogen gene-mutated renal tubular dysgenesis with glomerular cysts

BACKGROUND

Inherited renal tubular dysgenesis (RTD) is caused by mutations in the genes encoding the components of the renin-angiotensin system (RAS). RTD is characterized by oligohydramnios, renal failure, neonatal hypocalvaria, and severe hypotension. The histological characteristics, underlying mechanism, and long-term prognosis remain poorly known.

CASE-DIAGNOSIS/TREATMENT

We describe here a 4-year-old female with RTD. Endocrinologic analysis showed a discrepancy between low plasma renin activity and high active renin concentration, suggesting a loss of the renin substrate, angiotensinogen (AGT). Direct sequencing revealed a frameshift deletion at nucleotide 1,355 in exon 5 in the AGT gene. Although a histological hallmark is regarded to be the absence or poor development of the proximal tubule, the patient does have minimally impaired function of the proximal tubule. Glomerular cysts without glomerular tufts were noted in approximately half of the glomeruli. The urinary concentrating ability and sodium reabsorption and potassium excretion in the distal nephron were severely affected.

CONCLUSIONS

The patient has an impaired function of the distal nephron despite minimally affected function of the proximal tubule, probably attributed to renal tubular dysgenesis and fetal hypoperfusion. The renal tubular maturity and the severity of ischemic injury may be key determinants of the clinical symptoms and pathological findings in RTD, in which the RAS plays an important role.

Fetal renin-angiotensin-system blockade syndrome: renal lesions

BACKGROUND

Fetuses exposed to angiotensin-converting enzyme inhibitors or angiotensin receptor antagonists during the second and/or third trimesters of gestation are at high risk of developing severe complications. They consist in fetal hypotension, and anuria/oligohydramnios leading to Potter sequence, frequently associated with hypocalvaria. Most fetuses die during the pre- or postnatal period, whereas others recover normal or subnormal renal function. However, the secondary occurrence of renal failure or hypertension has been reported in children after apparent complete recovery.

METHODS

In this context, we analyzed renal lesions in 14 fetus/neonates who died soon after exposure to renin-angiotensin-system (RAS) blockers. Our objective was to determine the causes for the persistence or the secondary occurrence of renal complications reported in some of the survivors.

RESULTS

As previously described, renal tubular dysgenesis is usually observed. Additional lesions, such as thickening of the muscular wall of arterioles and interlobular arteries, glomerular cysts, and interstitial fibrosis, develop early during fetal life.

CONCLUSION

We suggest that renal lesions that develop before birth may persist after withdrawal of the causative drugs and normalization of blood and renal perfusion pressure. Their persistence could explain the severe long-term outcome of some of these patients. Long-term study of children exposed to RAS blockers during fetal life is strongly recommended.

Angiotensin-II receptor 1 antagonist fetopathy--risk assessment, critical time period and vena cava thrombosis as a possible new feature

AIMS

Angiotensin-II receptor 1 antagonists (AT₁-antagonists) may cause severe and even lethal fetopathy in late pregnancy. However, exposure still occurs in spite of warnings in package leaflets. This study aimed to assess the risk of fetopathy, the sensitive time window, and possible new symptoms in prospective as well as retrospective cases with AT₁-antagonist treatment during the second or third trimester of pregnancy.

METHODS

Patients were enrolled by the Berlin Institute for Clinical Teratology and Drug Risk Assessment in Pregnancy between 1999 and 2011 through risk consultation. Symptoms defined as indicative of AT₁-antagonist fetopathy were: oligo-/anhydramnios, renal insufficiency, lung hypoplasia, joint contractures, skull hypoplasia and fetal/neonatal death.

RESULTS

In 5/29 (17%) prospectively enrolled cases with AT₁-antagonist exposure beyond the first trimester oligo-/anhydramnios was diagnosed. Two infants showed additional symptoms of fetopathy. The risk is more than 30% if treatment continues beyond the 20th week of pregnancy. Oligo-/anhydramnios was reversible after AT₁-antagonist withdrawal. Among 16 retrospective case reports, three infants presented with a thrombosis of the inferior vena cava in the vicinity of the renal veins. Four out of 13 live births did not survive.

CONCLUSIONS

Our survey suggests that the risk increases with duration of AT₁-antagonist treatment into late pregnancy and oligo-/anhydramnios may be reversible after AT₁-antagonist discontinuation. Thrombosis of inferior vena cava may be a new feature of AT₁-antagonist fetopathy. AT₁-antagonist medication during pregnancy constitutes a considerable risk and must be discontinued immediately. In case of indicative diagnostic findings in either the fetus or newborn, previous maternal AT₁-antagonist exposure should be considered.

Perinatal Na+ overload programs raised renal proximal Na+ transport and enalapril-sensitive alterations of Ang II signaling pathways during adulthood

BACKGROUND

High Na(+) intake is a reality in nowadays and is frequently accompanied by renal and cardiovascular alterations. In this study, renal mechanisms underlying perinatal Na(+) overload-programmed alterations in Na(+) transporters and the renin/angiotensin system (RAS) were investigated, together with effects of short-term treatment with enalapril in terms of reprogramming molecular alterations in kidney.

METHODOLOGY/PRINCIPAL FINDINGS

Male adult Wistar rats were obtained from dams maintained throughout pregnancy and lactation on a standard diet and drinking water (control) or 0.17 M NaCl (saline group). Enalapril (100 mg/l), an angiotensin converting enzyme inhibitor, was administered for three weeks after weaning. Ninety day old offspring from dams that drank saline presented with proximal tubules exhibiting increased (Na(+)+K(+))ATPase expression and activity. Ouabain-insensitive Na(+)-ATPase activity remained unchanged but its response to angiotensin II (Ang II) was lost. PKC, PKA, renal thiobarbituric acid reactive substances (TBARS), macrophage infiltration and collagen deposition markedly increased, and AT(2) receptor expression decreased while AT(1) expression was unaltered. Early treatment with enalapril reduced expression and activity of (Na(+)+K(+))ATPase, partially recovered the response of Na(+)-ATPase to Ang II, and reduced PKC and PKA activities independently of whether offspring were exposed to high perinatal Na(+) or not. In addition, treatment with enalapril per se reduced AT(2) receptor expression, and increased TBARS, macrophage infiltration and collagen deposition. The perinatally Na(+)-overloaded offspring presented high numbers of Ang II-positive cortical cells, and significantly lower circulating Ang I, indicating that programming/reprogramming impacted systemic and local RAS.

CONCLUSIONS/SIGNIFICANCE

Maternal Na(+) overload programmed alterations in renal Na(+) transporters and in its regulation, as well as severe structural lesions in adult offspring. Enalapril was beneficial predominantly through its influence on Na(+) pumping activities in adult offspring. However, side effects including down-regulation of PKA, PKC and AT(2) receptors and increased TBARS could impair renal function in later life.

Is there an embryopathy associated with first-trimester exposure to angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists? A critical review of the evidence

Drugs that interfere with the renin-angiotensin system, such as angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), are widely used to manage hypertension and heart failure. Adequate functioning of the RAS is essential for normal fetal kidney development. The potential for ACEIs and ARBs to impair fetal and neonatal renal function if taken after the first trimester of pregnancy has been well documented. Although these drugs were not found to be teratogenic in animals, until recently little was known about the teratogenic effects of ACEIs and ARBs in humans when exposure was limited to the first trimester of pregnancy. New evidence from epidemiologic studies indicates that there may be an elevated teratogenic risk when these drugs are taken during the first trimester of pregnancy. However, this elevated risk does not appear to be specific to ACEIs and ARBs, but is instead related to maternal factors and diseases that typically coexist with hypertension in pregnancy, such as diabetes, advanced maternal age, and obesity. Women who become pregnant while being treated with an ACEI or ARB should be advised to avoid exposure to these drugs during the second and third trimesters of pregnancy by switching to a different class of antihypertensive drugs between weeks 8 and 10 after conception.

Children's toxicology from bench to bed--Drug-induced renal injury (1): The toxic effects of ARB/ACEI on fetal kidney development

Development of fetal kidney is a finely programmed sequence, and is regulated by many important molecules. The perturbation of normal kidney development leads to congenital anomalies of kidney and urinary tract (CAKUT). CAKUT includes hypoplastic/dysplastic kidney, obstructive nephropathy and several other anomalies. CAKUT is of clinically importance, since it could lead to end stage renal failure when its anomaly grade is severe. So far, several causative genes responsible for development of CAKUT have been identified, including genes encoding molecules related to the renin-angiotensin-aldosterone system, RAS system. In humans, maternal administration of agents with inhibitory effects on the RAS system, such as angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin type 1 receptor blockers (ARBs), have been reported to cause severe renal malformation, designated as ACEI/ARB fetopathy. In this paper, we overview the development of fetal kidney and address the effects of ACEIs/ARBs on fetal kidney.