Salt-losing crisis in infants-not always of adrenal origin

Transient secondary pseudo-hypoaldosteronism in infants with urinary tract infections: systematic literature review

Infants with a congenital anomaly of the kidney and urinary tract sometimes present with hyponatremia, hyperkalemia, and metabolic acidosis due to under-responsiveness to aldosterone, hereafter referred to as secondary pseudo-hypoaldosteronism. The purpose of this report is to investigate pseudo-hypoaldosteronism in infant urinary tract infection. A systematic review was conducted following PRISMA guidelines after PROSPERO (CRD42022364210) registration. The National Library of Medicine, Excerpta Medica, Web of Science, and Google Scholar without limitations were used. Inclusion criteria involved pediatric cases with documented overt pseudo-hypoaldosteronism linked to urinary tract infection. Data extraction included demographics, clinical features, laboratory parameters, management, and course. Fifty-seven reports were selected, detailing 124 cases: 95 boys and 29 girls, 10 months or less of age (80% of cases were 4 months or less of age). The cases exhibited hyponatremia, hyperkalemia, acidosis, and activated renin-angiotensin II-aldosterone system. An impaired kidney function was found in approximately every third case. Management included antibiotics, fluids, and, occasionally, emergency treatment of hyperkalemia, hyponatremia, or acidosis. The recovery time averaged 1 week for electrolyte, acid-base imbalance, and kidney function. Notably, anomalies of the kidney and urinary tract were identified in 105 (85%) cases.

CONCLUSIONS

This review expands the understanding of overt transient pseudo-hypoaldosteronism complicating urinary tract infection. Management involves antimicrobials, fluid replacement, and consideration of electrolyte imbalances. Raising awareness of this condition within pediatric hospitalists is desirable.

WHAT IS KNOWN

• Infants affected by a congenital anomaly of the kidney and urinary tract may present with clinical and laboratory features resembling primary pseudo-hypoaldosteronism. • Identical features occasionally occur in infant urinary tract infection.

WHAT IS NEW

• Most cases of secondary pseudo-hypoaldosteronism associated with a urinary tract infection are concurrently affected by a congenital anomaly of the kidney and urinary tract. • Treatment with antibiotics and parenteral fluids typically results in the normalization of sodium, potassium, bicarbonate, and creatinine within approximately 1 week.

Secondary pseudohypoaldosteronism: a 15-year experience and a literature review

BACKGROUND

Secondary pseudohypoaldosteronism (S-PHA) is a rare condition resulting from renal tubular resistance to aldosterone in children with urinary tract infection (UTI) and/or nephrourological malformations. It is characterized by nonspecific symptoms but with the potential for life-threatening complications. We aim to evaluate the clinical manifestations, diagnostic approach, and therapeutic interventions in children with S-PHA, along with a review of recent publications.

METHODS

A retrospective observational descriptive study was conducted on S-PHA cases diagnosed over the last 15 years at a tertiary pediatric nephrology unit. The literature for the last 10 years was reviewed.

RESULTS

Twelve patients (10 males, 6 days to 6 months) were identified. Weight loss was the main reason for consultation (50%). Ninety-two percent of patients had an underlying nephrourological pathology and 62% concomitant confirmed UTI. Seven out of 12 children were admitted to the PICU. A subsequent extrapontine myelinolysis was observed in one patient as neurological sequelae. Twenty-one articles related to S-PHA have been identified on PubMed and Embase.

CONCLUSIONS

S-PHA should be considered in infants under 6 months of age with UTI and/or CAKUT. Obstructive anomalies and vesicoureteral reflux can be found, affecting both unilateral and bilateral systems. Early medical and surgical interventions are crucial and require close monitoring to avoid iatrogenic complications.

Waterhouse-Friderichsen syndrome, septic adrenal apoplexy

Waterhouse-Friderichsen syndrome is a rare but potentially fatal disorder of the adrenal gland characterized by bilateral adrenal hemorrhage. It is classically a result of meningococcal sepsis and presents acutely with features of shock, petechial rashes, abdominal pain, and non-specific symptoms such as headache, fatigue, and vomiting. Treatment consists of fluid resuscitation, corticosteroid replacement, and possibly surgery. The prognosis is poor despite treatment. This chapter will review the etiology, pathogenesis, clinical features, and management of the disease.

Klebsiella oxytoca Complex: Update on Taxonomy, Antimicrobial Resistance, and Virulence

Klebsiella oxytoca is actually a complex of nine species-Klebsiella grimontii, Klebsiella huaxiensis, Klebsiella michiganensis, K. oxytoca, Klebsiella pasteurii, Klebsiella spallanzanii, and three unnamed novel species. Phenotypic tests can assign isolates to the complex, but precise species identification requires genome-based analysis. The K. oxytoca complex is a human commensal but also an opportunistic pathogen causing various infections, such as antibiotic-associated hemorrhagic colitis (AAHC), urinary tract infection, and bacteremia, and has caused outbreaks. Production of the cytotoxins tilivalline and tilimycin lead to AAHC, while many virulence factors seen in Klebsiella pneumoniae, such as capsular polysaccharides and fimbriae, have been found in the complex; however, their association with pathogenicity remains unclear. Among the 5,724 K. oxytoca clinical isolates in the SENTRY surveillance system, the rates of nonsusceptibility to carbapenems, ceftriaxone, ciprofloxacin, colistin, and tigecycline were 1.8%, 12.5%, 7.1%, 0.8%, and 0.1%, respectively. Resistance to carbapenems is increasing alarmingly. In addition to the intrinsic bla_OXY, many genes encoding β-lactamases with varying spectra of hydrolysis, including extended-spectrum β-lactamases, such as a few CTX-M variants and several TEM and SHV variants, have been found. bla_KPC-2 is the most common carbapenemase gene found in the complex and is mainly seen on IncN or IncF plasmids. Due to the ability to acquire antimicrobial resistance and the carriage of multiple virulence genes, the K. oxytoca complex has the potential to become a major threat to human health.

Aldosterone signaling defect in young infants: single-center report and review

BACKGROUND

Aldosterone (Ald) is a crucial factor in maintaining electrolyte and water homeostasis. Defect in either its synthesis or function causes salt wasting (SW) manifestation. This disease group is rare, while most reported cases are sporadic. This study aimed to obtain an overview of the etiology and clinical picture of patients with the above condition and report our rare cases.

METHODS

A combination of retrospective review and case studies was conducted at the Pediatric Endocrine unit of The First Affiliated Hospital Sun Yat Sen University from September 1989 to June 2020.

RESULTS

A total of 187 patients with SW were enrolled, of which 90.4% (n = 169) were diagnosed with congenital adrenal hyperplasia (CAH). SW type 21-hydroxylase deficiency accounted for 98.8% (n = 167) of CAH diagnosis, while 1.2% (n = 2) was of lipoid CAH. Non-CAH comprised 9.6% (n = 18) of the total patients whose etiologies included SF-1 gene mutation (n = 1), X-linked adrenal hypoplasia congenita (n = 9), aldosterone synthase deficiency (ASD, n = 4), and pseudo-hypoaldosteronism type 1 (PHA1, n = 1). Etiologies were not identified in three patients. All of patients with ASD and PHA1 exhibited SW syndrome in their early neonatal period. DNA sequencing showed mutations of CYP11B2 for P1-P4 and NR3C2 for P5. P1 and P2 were sibling brothers affected by compound heterozygous mutations of c.1121G > A (p.R374Q) and c.1486delC p.(L496fs); likewise, P4 was identified with compound heterozygous mutations of c.1200 + 1G > A and c.240-1 G > T; meanwhile P3 demonstrated c.1303G > A p.(G435S) homozygous mutation in CYP11B2 gene. Lastly, P5 showed c.1768 C > T p.(R590*) heterozygous mutation in the NR3C2 gene.

CONCLUSION

Etiology of infant with aldosterone defect was mostly congenital. Renal and adrenal imaging are recommended to exclude renal causes. If clinical picture is suggestive, normal plasma Ald in early infancy cannot rule out aldosterone insufficiency.

The incidence of transient infantile pseudohypoaldosteronism in Ireland: A prospective study

AIM

To review the clinical course, outcome and incidence of infantile salt wasting associated with urinary tract infection (UTI) and/or urinary tract malformation (UTM) over a two-year surveillance period on the island of Ireland.

METHODS

A two-year (2013-14) prospective surveillance undertaken via the Irish and Ulster Paediatric Surveillance Units. Monthly prepaid postcards were circulated to consultant paediatricians (n = 260) at all paediatric units on the island of Ireland. Infants under one year of age presenting for the first time with hyponatraemia (Na < 130 mmol/L) and/or hyperkalaemia (K > 5.0 mmol/L) associated with urosepsis/UTM were reported.

RESULTS

All 7 reported patients (6 male) had culture-proven UTI, and 5 (71%) also had an underlying UTM (one diagnosed antenatally). Four (57%) patients had a documented elevated serum aldosterone supporting secondary pseudohypoaldosteronism (PHA) as the underlying diagnosis. Data on aldosterone were not reported in the other 3 patients, but clinical features were suggestive of secondary PHA. The estimated incidence for the Irish population of transient PHA is 1 per 13,200 total live births per year.

CONCLUSIONS

Salt wasting is a rare complication of UTI, especially if associated with underlying UTM. Boys appear to be at particular risk.

Hyponatremia in childhood urinary tract infection

Acute urinary tract infection (UTI) is the most common bacterial infection in childhood. Although hyponatremia was described in ~ 2/3 of these children, its clinical significance is still unclear. Herein, we evaluated the prevalence and clinical implications of hyponatremia in children hospitalized with a UTI. Medical records of previously healthy children hospitalized between January 2011 and December 2016 with UTI were retrospectively reviewed. Patients (median age 5.5 months) were divided into two groups according to their sodium levels: normonatremia (Na ≥ 135 mEq/L) and hyponatremia (Na < 135 mEq/L). Hyponatremia diagnosed on admission was found in 114/219 children (49%). Hyponatremic patients experienced a more severe disease manifested by a longer hospital stay (3.8 vs 3.4 days, p = 0.003), a higher prevalence of abnormal findings on renal ultrasound (10 vs 2, p = 0.01), higher C-reactive protein (CRP) levels (8.6 vs 3.4 mg/dl, p = <0.001), and a negative correlation between sodium levels and CRP (r = - 0.38, p < 0.001).Conclusion:Hyponatremia occurs frequently in children hospitalized with UTI and is associated with elevated inflammatory markers and a more severe disease course. What is Known: • Hyponatremia, one of the most common electrolyte abnormalities, occurs in approximately 1/3 of hospitalized children and in 2/3 of children with pyelonephritis. • In certain cases of various medical conditions, hyponatremia has been shown to correlate with disease severity. What is New: • Hyponatremia in hospitalized children with UTI correlates with elevated inflammatory markers and a more severe disease course.

Hyponatremia in children under 100 days old: incidence and etiologies

Hyponatremia is one of the most common electrolyte disorders in hospitalized children. The underlying mechanisms are poorly understood and potentially multifactorial, making management difficult, particularly in neonates. This retrospective study aimed to determine the incidence and etiologies of hyponatremia in hospitalized children under the age of 100 days, in our pediatric tertiary care hospital over a 1-year period. The etiology of hyponatremia was determined by reviewing the data noted in each patient's medical reports. Neonatal hyponatremia had a prevalence of 4.3% (86/2012 patients) and was mostly hospital-acquired (74/86 patients). Fifty-nine patients (68.9%) were preterm neonates. The etiology was iatrogenic in 26 cases (30.2%). In other cases, hyponatremia was due to transient (23 patients, 26.7%) or genetic abnormalities of the renal mineralocorticoid pathway (3 patients, 3.4%), SIADH (12 patients, 14%), digestive disease (3 patients, 3.5%), acute renal failure (3 patients, 3.5%), or heart failure (1 patient, 1.2%).Conclusion: Our findings confirm that hyponatremia is a frequent electrolyte disorder in neonates. Various mechanisms underlie this condition, most of which could be prevented by optimized management. The prevalence of genetic hypoaldosteronism and pseudohypoaldosteronism was higher than expected. We provide a simple diagram to help physicians identify the mechanisms underlying neonatal hyponatremia. What is Known: • In neonates, hyponatremia may be multifactorial, making it difficult to treat. • Newborns display partial resistance to aldosterone, and preterms have a defect in aldosterone secretion. What is New: • Four percent of hospitalized neonates had hyponatremia, 86% hospital-acquired. Hyponatremia was due to a transient or constitutional defect of the mineralocorticoid pathway in 26/86 patients (30%) which is higher than expected. • We propose a tree diagram for improving the management of hyponatremia in neonates.

High aldosterone and cortisol levels in salt wasting congenital adrenal hyperplasia: a clinical conundrum

BACKGROUND

Salt wasting syndrome (hyponatremia, hyperkalemia, dehydration, metabolic acidosis) in early infancy could be caused by either mineralocorticoid deficiency as in congenital adrenal hyperplasia (CAH) and adrenal insufficiency or mineralocorticoid resistance as in pseudohypoaldosteronism (PHA). In salt wasting CAH, serum aldosterone and cortisol levels are expected to be low. Cross reactivity between high levels of adrenal steroid precursors and aldosterone has recently been reported resulting in elevated aldosterone levels in CAH, leading to difficulty in differentiating between CAH and PHA.

CASE PRESENTATION

We report four such cases of salt wasting CAH, where high aldosterone levels and high normal cortisol levels led to initial diagnostic confusion with PHA. Diagnosis of CAH was later established on the basis of significantly elevated adrenocorticotropic hormone (ACTH) stimulated 17-hydroxyprogesterone (17-OHP) values.

CONCLUSIONS

By reporting these cases we draw attention to the possibility that high levels of adrenal steroid precursors can cross react with aldosterone and cortisol, and underscore the significance of ACTH stimulated 17-OHP values in differentiating CAH and PHA.

Transient pseudohypoaldosteronism in infancy secondary to urinary tract infection

AIM

Hyponatraemia with hyperkalaemia in infancy is a typical presentation of congenital adrenal hyperplasia. In the presence of pyelonephritis, the same biochemical picture can occur with transient type 1 pseudohypoaldosteronism (PHA-1) also termed type 4 renal tubular acidosis. Recognition of PHA-1 enables appropriate management thus avoiding unnecessary investigations and treatment. To improve awareness of this condition, we present a case series to highlight the clinical and biochemical features of PHA-1.

METHODS

A retrospective chart review of patients diagnosed with transient PHA-1 at a tertiary children's hospital in Western Australia was conducted.

RESULTS

Five male infants (32 days to 6 months) with transient PHA-1 were identified. Failure to thrive was the most common symptom with hyponatraemia on presentation. Two infants had antenatally diagnosed bilateral hydronephrosis and urinary tract infection (UTI) on admission. Two infants were treated for congenital adrenal hyperplasia and received hydrocortisone. All infants had UTI and required parenteral antibiotics. The condition was transient and hyponatraemia corrected by day 4 in all infants. There was no correlation between plasma sodium and aldosterone levels. The severity of PHA-1 was independent of the underlying renal anomaly. Four infants had hydronephrosis and vesicoureteric reflux. Surgical intervention was required in two infants.

CONCLUSIONS

PHA-1 may be precipitated by UTI or urinary tract anomalies in early infancy. Urine analysis should be performed in infants with hyponatraemia. Diagnosis of PHA-1 facilitates appropriate renal investigations to reduce long-term morbidity.