Tangled relationship between insulin resistance and microalbuminuria in children with obesity

Childhood obesity represents a complex disease with a well-known cardiometabolic burden including fatty liver, type 2 diabetes, metabolic syndrome, and cardiovascular disease. From a pathogenic point of view, insulin resistance (IR) represents the key factor underlying the spectrum of these obesity consequences. As observed in adults, recent data supported the occurrence of microalbuminuria (MA) as marker of early kidney dysfunction and its potential link with cardiometabolic factors also in children with obesity. In fact, a well-documented pathophysiological hypothesis both in adults and children supported an intimate correlation with the major feature of obesity such as IR through the influence of insulin on renal hemodynamics. Based on the clinical and prognostic relevance of this relationship in daily practice (including an increased risk of chronic kidney disease development overtime), more scientific attention needs to be paid to the evaluation of early kidney damage in children with obesity. In this paper, we attempt to address three debated questions regarding the intriguing liaison between IR and MA in children with obesity: (1) What is the prevalence of pediatric MA? (2) What is the state of art of MA in children with obesity? and (3) Is there a link between IR and MA in children with obesity?

Gut microbiota and COVID-19: An intriguing pediatric perspective

Gastrointestinal (GI) involvement has been reported in approximately 50% of patients with coronavirus disease 2019 (COVID-19), which is due to the pathogenic role of inflammation and the intestinal function of the angiotensin-converting enzyme 2 and its receptor. Accumulating adult data has pointed out that gut dysbiosis might occur in these patients with a potential impact on the severity of the disease, however the role of gut microbiota in susceptibility and severity of COVID-19 disease in children is still poorly known. During the last decades, the crosstalk between gut and lung has been largely recognized resulting in the concept of “gut-lung axis” as a central player in modulating the development of several diseases. Both organs are involved in the common mucosal immune system (including bronchus-associated and gut-associated lymphoid tissues) and their homeostasis is crucial for human health. In this framework, it has been found that the role of GI dysbiosis is affecting the homeostasis of the gut-liver axis. Of note, a gut microbiome imbalance has been linked to COVID-19 severity in adult subjects, but it remains to be clarified. Based on the increased risk of inflammatory diseases in children with COVID-19, the potential correlation between gut microbiota dysfunction and COVID-19 needs to be studied in this population. We aimed to summarize the most recent evidence on this striking aspect of COVID-19 in childhood.

Metabolic-associated fatty liver disease from childhood to adulthood: State of art and future directions

In 2020, an international group of experts proposed to replace the term of nonalcoholic fatty liver disease with metabolic-associated fatty liver disease (MAFLD). This recent proposal reflects the close association of fatty liver with metabolic derangements, as demonstrated by previous robust data. Several factors [including genetics, inflammation, metabolic abnormalities, insulin resistance (IR), obesity, prenatal determinants, and gut–liver axis] have been found to be involved in MAFLD pathophysiology, but this tangled puzzle remains to be clearly understood. In particular, IR has been recognized as a key player in metabolic impairments development in children with fatty liver. On this ground, MAFLD definition focuses on the pathophysiological basis of the disease, by emphasizing the crucial role of metabolic impairments in this condition. Although primarily developed for adults, MAFLD diagnostic criteria have been recently updated with an age-appropriate definition for sex and age percentiles, because of the increasing attention to cardiometabolic risk in childhood. To date, accumulating evidence is available on the feasibility of MAFLD definition in clinical practice, but some data are still conflicting in highly selected populations. Considering the growing prevalence worldwide of fatty liver and its close relationship with metabolic dysfunction both in children and adults with subsequent increased cardiovascular risk, early strategies for MAFLD identification, treatment and prevention are needed. Novel therapeutic insights for MAFLD based on promising innovative biological techniques are also emerging. We aimed to summarize the most recent evidence in this intriguing research area both in children and adults.

Advances in pediatric non-alcoholic fatty liver disease: From genetics to lipidomics

As a result of the obesity epidemic, non-alcoholic fatty liver disease (NAFLD) represents a global medical concern in childhood with a closely related increased cardiometabolic risk. Knowledge on NAFLD pathophysiology has been largely expanded over the last decades. Besides the well-known key NAFLD genes (including the I148M variant of the PNPLA3 gene, the E167K allele of the TM6SF2, the GCKR gene, the MBOAT7-TMC4 rs641738 variant, and the rs72613567:TA variant in the HSD17B13 gene), an intriguing pathogenic role has also been demonstrated for the gut microbiota. More interestingly, evidence has added new factors involved in the “multiple hits” theory. In particular, omics determinants have been highlighted as potential innovative markers for NAFLD diagnosis and treatment. In fact, different branches of omics including metabolomics, lipidomics (in particular sphingolipids and ceramides), transcriptomics (including micro RNAs), epigenomics (such as DNA methylation), proteomics, and glycomics represent the most attractive pathogenic elements in NAFLD development, by providing insightful perspectives in this field. In this perspective, we aimed to provide a comprehensive overview of NAFLD pathophysiology in children, from the oldest pathogenic elements (including genetics) to the newest intriguing perspectives (such as omics branches).

Omics era in type 2 diabetes: From childhood to adulthood

Parallel to the dramatic rise of pediatric obesity, estimates reported an increased prevalence of type 2 diabetes (T2D) already in childhood. The close relationship between obesity and T2D in children is mainly sustained by insulin resistance (IR). In addition, the cardiometabolic burden of T2D including nonalcoholic fatty liver disease, cardiovascular disease and metabolic syndrome is also strictly related to IR. Although T2D pathophysiology has been largely studied in an attempt to improve therapeutic options, molecular mechanisms are still not fully elucidated. In this perspective, omics approaches (including lipidomics, metabolomics, proteomics and metagenomics) are providing the most attractive therapeutic options for T2D. In particular, distinct both lipids and metabolites are emerging as potential therapeutic tools. Of note, among lipid classes, the pathogenic role of ceramides in T2D context has been supported by several data. Thus, selective changes of ceramides expression might represent innovative therapeutic strategies for T2D treatment. More, distinct metabolomics pathways have been also found to be associated with higher T2D risk, by providing novel potential T2D biomarkers. Taken together, omics data are responsible for the expanding knowledge of T2D pathophysiology, by providing novel insights to improve therapeutic strategies for this tangled disease. We aimed to summarize the most recent evidence in the intriguing field of the omics approaches in T2D both in adults and children.

Association between Hepatic Steatosis and Obstructive Sleep Apnea in Children and Adolescents with Obesity

BACKGROUND

Owing to the increasing rate of pediatric obesity, its complications such as non-alcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA) have become prevalent already in childhood. We aimed to assess the relationship between these two diseases in a cohort of children with obesity.

METHODS

We enrolled 153 children with obesity (mean age 10.5 ± 2.66, mean BMI 30.9 ± 5.1) showing OSA. Subjects underwent a laboratory evaluation, a cardio-respiratory polysomnography (PSG), and a liver ultrasound.

RESULTS

All subjects had a clinical diagnosis of OSA based on the AHI > 1/h (mean AHI 8.0 ± 5.9; range 2.21-19.0). Of these, 69 showed hepatic steatosis (62.3% as mild, 20.3% as moderate, and 17.4% as severe degree). A strong association between ALT and apnea/hypopnea index (AHI) was observed (p = 0.0003). This association was not confirmed after adjusting for hepatic steatosis (p = 0.53). By subdividing our population according to the presence/absence of steatosis, this association was found only in the steatosis group (p = 0.009). As the severity of steatosis increased, the significance of its association with AHI compared to the absence of steatosis became progressively stronger (all p < 0.0001).

CONCLUSIONS

Hepatic steatosis seems to drive the association between OSA and ALT levels, suggesting a potential pathogenic role of OSA in NAFLD.

Relationship between nonalcoholic fatty liver disease and chronic kidney disease could start in childhood

The relationship between nonalcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) has gained considerable scientific interest in adults over the past few years. However, this association has recently emerged in children. Several published studies have suggested a role for NAFLD as a risk factor for CKD from the earliest age, with a potential influence of the major NAFLD risk polymorphisms, resulting in an increased risk of both cardiovascular and metabolic diseases. In view of the progressive course and increased cardiometabolic risk closely related to NAFLD and CKD, we focused on the link between these diseases in childhood.

Advances in paediatric nonalcoholic fatty liver disease: Role of lipidomics

Due its close relationship with obesity, nonalcoholic fatty liver disease (NAFLD) has become a major worldwide health issue even in childhood. The most accepted pathophysiological hypothesis is represented by the “multiple hits” theory, in which both hepatic intracellular lipid accumulation and insulin resistance mainly contribute to liver injury through several factors. Among these, lipotoxicity has gained particular attention. In this view, the pathogenic role of different lipid classes in NAFLD (e.g., sphingolipids, fatty acids, ceramides, etc.) has been highlighted in recent lipidomics studies. Although there is some contrast between plasma and liver findings, lipidomic profile in the NAFLD context provides novel insights by expanding knowledge in the intricate field of NAFLD pathophysiology as well as by suggesting innovative therapeutic approaches in order to improve both NAFLD prevention and treatment strategies. Selective changes of distinct lipid species might be an attractive therapeutic target for treating NAFLD. Herein the most recent evidence in this attractive field has been summarized to provide a comprehensive overview of the lipidomic scenario in paediatric NAFLD.

COVID-19 and pediatric fatty liver disease: Is there interplay?

The rapid global spread of coronavirus disease 2019 (COVID-19) infection has become a major health issue with higher morbidity and mortality rates. Besides respiratory symptoms, a growing body of evidence indicates a variety of gastrointestinal manifestations including liver involvement. In this regard, several data supported an association between COVID-19 infection and liver injury in adults, while in children there is compelling but currently limited evidence. In particular, patients with COVID-19 have shown a higher risk of liver injury (mainly expressed as increased transaminase levels or hepatic steatosis). Conversely, a greater risk of more severe forms of COVID-19 infection has been observed in subjects with pre-existing chronic liver diseases. The dramatic interplay between COVID-19 and liver damage has been related to the inflammatory pathways chronically active in patients with nonalcoholic fatty liver disease and acutely in those affected by COVID-19, but other different pathogenic mechanisms have also been supposed. Of note, patients with previous metabolic comorbidities also had a higher risk of severe COVID-19 infection. This emphasizes the pathogenic interrelation of the inflammatory pathways with a dysregulated metabolic milieu in COVID-19 patients. Taking into account the prognostic role of fatty liver in COVID-19 patients and its intrinsic relationship with metabolic abnormalities even in childhood, a strict monitoring of this condition is recommended. We aimed to summarize the most recent evidence regarding the potential interplay between pediatric fatty liver and COVID-19.

Telemedicine in the COVID-19 era: Taking care of children with obesity and diabetes mellitus

Severe acute respiratory syndrome coronavirus 2 infection was declared a pandemic in January 2020. Since then, several measures to limit virus transmission have been imposed; among them, home confinement has been the most severe, with drastic changes in the daily routines of the general population. The “stay at home” rule has impaired healthcare service access, and patients with chronic conditions were the most exposed to the negative effects of this limitation. There is strong evidence of the worsening of obesity and diabetes mellitus in children during this period. To overcome these issues, healthcare providers have changed their clinical practice to ensure follow-up visits and medical consultation though the use of telemedicine. Telemedicine, including telephone calls, videocalls, data platforms of shared telemedicine data platforms mitigated the negative effect of pandemic restrictions. Published evidence has documented good metabolic control and weight management outcomes in centers that performed extensive telemedicine services last year during the pandemic. This review discusses studies that investigated the use of telemedicine tools for the management of pediatric obesity and diabetes.

How to interpret symptoms, signs and investigations of dehydration in children with gastroenteritis

Dehydration is a significant cause of morbidity and mortality in children worldwide. Infants and young children are vulnerable to dehydration, and clinical assessment plays a pivotal role in their care. In addition, laboratory investigations can, in some children, be helpful when assessing the severity of dehydration and for guiding rehydration treatment. In this interpretation, we review the current literature and provide an evidence-based approach to recognising and managing dehydration in children.

Prevalence of Mildly Reduced Estimated GFR by Height- or Age-Related Equations in Young People With Obesity and Its Association with Cardiometabolic Risk Factors

OBJECTIVE

To compare the prevalence of mildly reduced estimated glomerular filtration rate (MRGFR) (eGFR >60 and < 90 mL/min/1.73 m²), calculated by two creatinine-based equations, and its association with cardiometabolic risk factors (CMRF) in youth with overweight (OW)/obesity (OB).

METHODS

This is a multicenter cross-sectional study involving university and non-university hospital pediatrics departments. We enrolled 3,118 youth with OW/OB (5-14 years) and 286 healthy normal weight (NW) youth. eGFR was calculated using bedside Schwartz equation (eGFRBSE) and Full Age Spectrum equation (eGFRFAS). In OW/OB group we analyzed the association between eGFR calculated by both equations and CMRF. Uric acid (UA) and birth weight were available in 2,135 and in 1,460 youth.

RESULTS

The prevalence of MRGFR was 3.8% in NW versus 7.8% in OW/OB (P = .016) by eGFRBSE, and 8.7% in NW versus 19.4% in OW/OB (P < .0001) by eGFRFAS. eGFRBSE and eGFRFAS identified 242 and 605 young people with OW/OB with MRGFR, respectively. Individuals with MRGFR according with both equations showed lower birth weight, younger age, higher BMI-SDS, non-high-density lipoprotein-cholesterol and UA as compared to those with normal eGFR. To examine whether the eGFRFAS was associated with a worse CMR profile also in the range of normal eGFRBSE, we reclassified young people with normal eGFRBSE (n = 2,876) according with eGFRFAS. Out of youth with normal eGFRBSE, 366 (12.7%) presented MRGFR by eGFRFAS and had lower age, higher BMI-SDS, BP and UA than the remaining youth reclassified as normal eGFRFAS.

CONCLUSION

MRGFR is associated with an altered CMR profile in a large sample of young people with overweight (OW)/obesity (OB). The eGFRFAS equation identifies a higher prevalence of youth with MRGFR, compared to eGFRBSE equation.

Prevalence of and factors associated to chronic kidney disease and hypertension in a cohort of children with juvenile idiopathic arthritis

We evaluated chronic kidney disease (CKD) (proteinuria or estimated glomerular filtration rate < 60 mL/min/1.73 m²) or hypertension prevalence in 110 children with juvenile idiopathic arthritis (JIA). CKD and hypertension were clustered under the umbrella term of "renal injury". Median age at the last visit was 14 years. Nine out of 110 (8.1%) patients showed renal injury (8 hypertension, 1 proteinuria). Patients with renal injury presented higher age at last visit, longer duration of active JIA, shorter intervals free from JIA relapses, longer duration of non-steroidal anti-inflammatory drugs (NSAIDs) treatment but with similar cumulative NSAIDs dose and higher rate of methotrexate (MTX) prescription, longer time of MTX administration, and higher cumulative MTX dose compared to patients without renal injury. At the last visit, patients with and without renal injury presented similar prevalence of active disease. The cumulative proportion of patients free from renal injury at 240 months since JIA onset was 40.72% for all population; while the cumulative proportion was 23.7% for patients undergoing NSAIDs+MTX treatment and 100% for those undergoing NSAIDs (p = 0.039) treatment.Conclusion:About 8% of the children with JIA develop hypertension or CKD. The main risk factor was longer exposure to both NSAIDs and MTX due to a more severe form of the disease. What is Known •Anecdotal reports showed that rarely juvenile idiopathic arthritis (JIA) could present renal involvement due to prolonged and uncontrolled inflammation (renal amyloidosis) or to long exposure to anti-rheumatic drugs. •No cohort studies investigated renal health in children with JIA. What is new •About 8% of the children with JIA developed hypertension or chronic kidney disease. •The main risk factor was long exposure to non-steroidal anti-inflammatory drugs and methotrexate for patients suffering from a more severe form of the disease. •In JIA patients, periodic evaluation of renal function, blood pressure and proteinuria should be warranted.

Dehydrated patient without clinically evident cause: A case report

BACKGROUND

Patients affected by cystic fibrosis can present with metabolic alkalosis such as Bartter’s syndrome. In this case report we want to underline this differential diagnosis and we aimed focusing on the suspect of cystic fibrosis, also in case of a negative newborn screening.

CASE SUMMARY

In a hot August –with a mean environmental temperature of 36 °C– an 8-mo-old female patient presented with severe dehydration complicated by hypokalemic metabolic alkalosis, in absence of fever, diarrhea and vomiting. Differential diagnosis between cystic fibrosis and tubulopathies causing metabolic alkalosis (Bartter’s Syndrome) was considered. We started intravenous rehydration with subsequent improvement of clinical conditions and serum electrolytes normalization. We diagnosed a mild form of cystic fibrosis (heterozygous mutations: G126D and F508del in the cystic fibrosis transmembrane conductance regulator gene). The trigger factor of this condition had been heat exposure.

CONCLUSION

When facing a patient with hypokalemic metabolic alkalosis, cystic fibrosis presenting with Pseudo-Bartter’s syndrome should be considered in the differential diagnosis, even if the newborn screening was negative.

Pediatric non-alcoholic fatty liver disease and kidney function: Effect of HSD17B13 variant

BACKGROUND

Growing evidence supports a genetic link between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD). Interesting data demonstrated that both the major NAFLD risk polymorphisms such as the I148M polymorphism in the patatin like phospholipase containing domain 3 (PNPLA3) and the E167K allele in the transmembrane 6 superfamily member 2 gene (TM6SF2) affect renal function. Recently the hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) gene has been recognized as a novel genetic variant involved in NAFLD pathophysiology. In particular, it has been showed the protective effect of the rs72613567:TA variant of this gene against liver damage both in adults and children.

AIM

To investigate the impact of the rs72613567:TA variant of the HSD17B13 gene on estimated glomerular filtration rate (eGFR) in obese children.

METHODS

We enrolled 684 obese children (mean age 10.56 ± 2.94 years; mean BMI-SDS 2.98 ± 0.78) consecutively attending our Obesity Clinic. All the patients underwent a careful clinical assessment and a comprehensive biochemical evaluation. To detect hepatic steatosis, a liver ultrasound was performed. NAFLD was defined by ultrasound detected liver steatosis and/or alanine aminotransferase (ALT) levels > 40 IU/L. The study population was divided on the basis of the NAFLD presence. Genotyping for the rs72613567:TA variant of the HSD17B13 gene in all the enrolled subjects was also made.

RESULTS

Patients carrying the HSD17B13 rare A allele showed higher eGFR levels compared with homozygous patients both among subjects with and without NAFLD. A general linear model confirmed a direct and significant association of eGFR values with HSD17B13 genotype independently of PNPLA3 and TM6SF2 polymorphisms both in patients with and without NAFLD. A comparison of regression line confirmed the influence of HSD17B13 genotype on the relationship between eGFR and age both among patients with and without NAFLD. Homozygous patients for HSD17B13 genotype with NAFLD showed a significantly higher decline of eGFR with the increase of the age compared with the patients with NAFLD carrying the HSD17B13 rare A allele (P value for intercepts = 0.005; P value for slopes = 0.94). The same effect was observed among patients without NAFLD (P value for intercepts = 0.0012; P value for slopes = 0.87).

CONCLUSION

Carriers of the HSD17B13 rare A allele showed higher eGFR levels than homozygous subjects both among subjects with and without NAFLD and independently of PNPLA3 I148M and TM6SF6 E167K polymorphisms.

Nephrogenic Diabetes Insipidus in Childhood: Assessment of Volume Status and Appropriate Fluid Replenishment

Patients affected by nephrogenic diabetes insipidus (NDI) can present with hypernatremic dehydration, and first-line rehydration schemes are completely different from those largely applied in usual conditions determining a mild to severe hypovolemic dehydration/shock. In reporting the case of a patient affected by NDI and presenting with severe dehydration triggered by acute pharyngotonsillitis and vomiting, we want to underline the difficulties in managing this condition. Restoring the free-water plasma amount in patients affected by NDI may not be easy, but some key points can help in the first line management of these patients: (1) hypernatremic dehydration should always be suspected; (2) even in presence of severe dehydration, skin turgor may be normal and therefore the skinfold recoll should not be considered in the dehydration assessment; (3) decreased thirst is an important red flag for dehydration; (4) if an incontinent patient with NDI appears to be dehydrated, it is important to place the urethral catheter to accurately measure urine output and to be guided in parenteral fluid administration; (5) if the intravenous route is necessary, the more appropriate fluid replenishment is 5% dextrose in water with an infusion rate that should slightly exceed the urine output; (6) the 0.9% NaCl solution (10 mL/kg) should only be used to restore the volemia in a shocked NDI patient; and (7) it could be useful to stop indomethacin administration until complete restoration of hydration status to avoid a possible worsening of a potential prerenal acute renal failure.

In children with urinary tract infection reduced kidney length and vesicoureteric reflux predict abnormal DMSA scan

BACKGROUND

To evaluate sensitivity, specificity, and positive and negative predictive values (PPV and NPV, respectively) of renal ultrasonography (US) in predicting renal uptake defects or reduced renal function at Tc-99m dimercaptosuccinic acid (DMSA) scan (primary outcome). We also evaluated which factors could be associated with Tc-99m DMSA renal scan anomalies.

METHODS

We retrospectively included all the patients with vesico-ureteral reflux (VUR) undergoing the first Tc-99m DMSA renal scan within 3 months from the most recent renal US between 2016 and 2018.

RESULTS

Sensitivity, specificity, PPV, and NPV of US in predicting abnormal Tc-99m DMSA scan were 38.9%, 91.5%, 71.9%, and 72.9%, respectively. Different length between the kidneys, expressed as standard deviation score (SDS), showed an area under the receiver operating characteristic curve of 0.70 (95% CI, 0.60-0.80; p < 0.0001) when evaluated as predictor of abnormal Tc-99m DMSA scan. A different length between the two kidneys >1.11 SDS had 91.5% sensitivity and 57.6% specificity. At multivariate analysis, the factors with significantly increased odds ratio of abnormal Tc-99m DMSA scan were difference in length between two kidneys >1.11 SDS and dilated VUR.

CONCLUSIONS

The Tc-99m DMSA scan remains the gold standard to detect renal parenchymal anomalies. A different length between the kidneys >1.11 SDS and dilated VUR are predictors of abnormal Tc-99m DMSA renal scan.

Pilot study showed that poor feeding, especially with leucocyturia, increased the odds of non-febrile urinary tract infections in children who were not toilet trained

AIM

This study assessed the prevalence of wrongly diagnosed non-febrile urinary tract infections in patients who had not been toilet trained and presented with poor feeding and, or, failure to thrive. The diagnostic value of these signs in predicting non-febrile UTIs was also explored.

METHODS

We focused on 59 outpatients (56.7% male) with these criteria, who had positive urine cultures and were referred to our Italian University hospital from January 2017 to January 2019. None were on antibiotics and all underwent urine cultures by bladder catheterisation. Wrongly diagnosed non-febrile UTIs were defined by sterile urine cultures. The predictive value was evaluated using logistic regression.

RESULTS

The mean age was 8.5 ± 5.7 months and 72.9% had wrongly diagnosed non-febrile UTIs. Poor feeding was significantly higher among the 16 patients with true non-febrile UTIs (P = .04). It was significantly predictive of non-febrile UTIs (odds ratio 4.1, 95% confidence interval 1.1-16.6), especially when leucocyturia was present (odds ratio 9.7, 95% confidence interval 2.3-40.7).

CONCLUSION

Wrongly diagnosed non-febrile UTIs were high in children with poor feeding and, or, failure to thrive. Only poor feeding and, in particular, the combination of poor feeding and leucocyturia, significantly increased the odds of non-febrile UTI.

Nonalcoholic fatty liver disease and eGFR levels could be linked by the PNPLA3 I148M polymorphism in children with obesity

BACKGROUND

PNPLA3 I148M polymorphism has an effect on modulation of estimated glomerular filtration rate (eGFR) in nonobese nondiabetic adults and in children with histologically confirmed nonalcoholic fatty liver disease (NAFLD).

OBJECTIVES

The objective of the study is to explore the impact of PNPLA3 I148M polymorphism on eGFR in children with obesity with and without NAFLD.

METHODS

We genotyped 591 patients with obesity for PNPLA3 I148M polymorphism. Anthropometrical, biochemical, and instrumental data were collected. NAFLD was defined by the presence of ultrasound-detected liver steatosis and/or ALT levels greater than 40 IU/L.

RESULTS

Patients with NAFLD showed significantly lower eGFR levels compared with subjects without NAFLD. Children with PNPLA3 MM genotype showed lower eGFR levels compared with those with either PNPLA3 IM or II genotypes both in the presence and absence of NAFLD. A general linear model for eGFR variance, including gender, duration of obesity, PNPLA3 genotypes, HOMA, BMI-SDS, LDL-C, and triglycerides as covariates, confirmed an inverse association between eGFR and PNPLA3 genotype only in the presence of NAFLD.

CONCLUSIONS

Children with obesity and PNPLA3 MM genotype show lower eGFR levels compared with other genotypes, with a major effect of this polymorphism in the presence of NAFLD.

Effect of Body Mass Index on Estimated Glomerular Filtration Rate Levels in Children With Congenital Solitary Kidney: A Cross-Sectional Multicenter Study

RATIONALE & OBJECTIVE

The objective of this study is to evaluate the effect of body mass index (BMI) on estimated glomerular filtration rate (eGFR) levels in children with congenital solitary kidney (CSK). Moreover, we evaluated if other factors could influence this relationship.

STUDY DESIGN

Multicenter cross-sectional study.

SETTING & PARTICIPANTS

University hospital pediatrics departments.

SUBJECTS

Two hundred eighty-one patients with CSK.

PREDICTORS

Weight, height, BMI-SDS (standard deviation score), duration of overweight/obesity, pubertal stage, systolic (SBP) and diastolic (DBP) blood pressure, eGFR, and renal ultrasound were obtained at the last follow-up visit. The population was classified on the basis of nutritional status and divided in tertiles for duration of overweight/obesity. We compared eGFR levels among these categories. A simple regression was used to correlate eGFR with BMI-SDS. To evaluate if other factors could influence the relationship between eGFR and BMI-SDS, a general linear model was performed, including gender, birth weight<2.5 kg, age, BMI-SDS, SBP-SDS, DBP-SDS, RL-SDS (renal length), and presence of kidney injury at last follow-up as covariates.

RESULTS

The eGFR levels reduced gradually from underweight to obese patients (P = .047). The eGFR levels significantly increased across first and second tertiles of duration of overweight/obesity while they decreased across second and third tertiles of duration of overweight/obesity (P = .005). The eGFR and BMI-SDS at last follow-up were indirectly correlated (coefficient = -0.30, r² = 9.2%, P = .0004). A general linear model for eGFR variance (model R² = 26.37%; P = .02) confirmed an indirect and significant association of eGFR values with BMI-SDS as the only significant finding.

CONCLUSIONS

In patients with CSK, the higher the BMI-SDS and the duration of overweight/obesity, the lower the eGFR levels. Primary prevention strategies to counteract overweight/obesity are mandatory in CSK patients.

Ventricular Tachycardia Induced by Propafenone Intoxication in a Pediatric Patient

Unintentional poisonings are a global health problem frequently resulting in hospital admissions. Propafenone is a class 1C antiarrhythmic drug used in the second-line management of supraventricular and ventricular arrhythmias and, when unintentionally ingested, can lead to severe and life-threatening poisoning. We describe a case of a 3-year-old male patient unintentionally ingesting 300 mg (20 mg/kg) of propafenone and presenting with ventricular tachycardia with QT prolongation. Two boli of intravenous hypertonic sodium bicarbonate (total amount of 3 mEq/kg), followed by 3-hours continuous infusion of 1 mEq kg h sodium bicarbonate, were able to restore the clinical conditions of the patient. With this case report, we aim to highlight the existing challenge in the therapeutic management of propafenone intoxication that finds intravenous hypertonic bicarbonate to be a useful tool also in pediatric population.

Pediatric non-alcoholic fatty liver disease: current perspectives on diagnosis and management

Non-alcoholic fatty liver disease (NAFLD) represents the most common cause of chronic liver disease in childhood. To date, the “multiple-hit” hypothesis is largely recognized as an explanation of NAFLD pathogenesis and progression. Obesity and features of the metabolic syndrome have been closely linked to NAFLD development. Due to the increased prevalence of obesity worldwide, NAFLD has reached epidemic proportions over time. Given its unfavorable cardiometabolic burden (such as cardiovascular and metabolic consequences), it represents a worrying phenomenon needing a more comprehensive and successful management. Laboratory tests and classical imaging techniques play a pivotal role in NAFLD diagnosis, but novel noninvasive alternative methods to diagnose and monitor NAFLD have been investigated. Currently, lifestyle modifications remain the mainstay treatment, although its efficacy is poor because of the lack of compliance. Pediatric research is focusing on multiple alternative treatments targeting the main pathogenic factors such as insulin-resistance, dyslipidemia, gut-liver axis and microbiota, oxidative stress, and proinflammatory pathways. Results from these studies are promising but larger validation is needed. Innovative therapeutic approaches might add an important piece in the complex knowledge of pediatric NAFLD. We aimed to summarize recent insights into NAFLD diagnosis and treatment in children, with a focus on possible future perspectives in pediatric research.

Rituximab-induced IgG hypogammaglobulinemia in children with nephrotic syndrome and normal pre-treatment IgG values

BACKGROUND

In paediatric patients with complicated nephrotic syndrome (NS), rituximab (RTX) administration can induce persistent IgG hypogammaglobulinemia among subjects showing low basal immunoglobulin G (IgG) levels.

AIM

To evaluate the effect of RTX on IgG levels and infections in patients with complicated NS and normal basal IgG levels.

METHODS

We consecutively enrolled all patients with complicated NS and normal basal IgG levels undergoing the first RTX infusion from January 2008 to January 2016. Basal IgG levels were dosed after 6 wk of absent proteinuria and with a maximal interval of 3 mo before RTX infusion. The primary outcome was the onset of IgG hypogammaglobulinemia during the follow-up according to the IgG normal values for age [mean ± standard deviation (SD)].

RESULTS

We enrolled 20 patients with mean age at NS diagnosis of 4.2 ± 3.3 years. The mean age at the first RTX infusion was 10.9 ± 3.5 years. Eleven out of twenty patients (55%) developed IgG hypogammaglobulinemia. None of these patients showed severe or recurrent infections. Only one patient suffered from recurrent acute otitis media and underwent substitutive IgG infusion. Three patients undergoing only the two “starting doses” experienced normalization of IgG levels. Using Kaplan-Meier analysis, the cumulative proportion of patients free of IgG hypogammaglobulinemia was 57.8% after the first RTX dose, 51.5% after the third dose, 44.1% after the fourth dose, and 35.5% after the fifth dose.

CONCLUSION

RTX can induce IgG hypogammaglobulinemia in patients with pre-RTX IgG normal values. None of the treated patients showed severe infections.

Micturition Syncope in Childhood: How to Recognize and Manage It

Frequently, general pediatricians could face a patient with syncope, which represents approximately 1% to 3% of emergency visits. Micturition syncope is a transient loss of consciousness with onset immediately before, during, or after micturition. Literature evidence indicates that healthy young men are a population with major risk for presenting micturition syncope, with a peak of incidence around 40 to 50 years of age. Usually, this syncope occurs in the morning, after wake-up, or, more generally, when the male patients assume the orthostatic position after a period of supine position in a warm bed. No information on micturition syncope clinical presentation and prevalence in childhood is available in the literature, and probably, this kind of syncope is unrecognized in childhood. We describe 4 unreported pediatric patients with a diagnosis of micturition syncope and well-defined clinical presentation. In all patients, the syncope has been presented in the same conditions: in the morning; after wake-up; in an orthostatic position; just before, after, or during urinary bladder voiding; and with spontaneous recovery in few minutes. Interestingly, 1 patient presented with the syncope during urinary bladder voiding by autocatheterization. In our patients, all investigations made as the first approach in the pediatric emergency department did not show any abnormal results, possibly underlying the syncope episodes. By describing our experience, we want to underline the clinical presentation of micturition syncope and give to the clinicians the elements to recognize and manage it easily in children.

Antibiotics for urethral catheterization in children undergoing cystography: retrospective evaluation of a single-center cohort of pediatric non-toilet-trained patients

Antibiotics are often used to prevent post-catheterization urinary tract infections (UTIs) in patients undergoing cystography. However, there is no universally accepted protocol and the literature data are conflicting. We aimed to determine prevalence and risk factors of post-cystography UTIs in non-toilet-trained children. We retrospectively evaluated 216 non-toilet-trained children not assuming antibiotics when undergoing cystography. Only the patients with dilated vesico-ureteral reflux (VUR) assumed antibiotics just after the exam (within 15 min). One hundred eleven patients without vesico-ureteral reflux (VUR) and 29 patients with non-dilated VUR did not receive post-procedure antibiotics and did not develop UTIs. Out of the 76 patients who showed a dilated VUR and received post-procedure antibiotics, only 5 (6.6%) developed a UTI. The most significant factor associated with post-cystography UTIs was the presence of dilated VUR (p = 0.005) with the presence of bilateral VUR also being significant (p = 0.02).Conclusion: Patients without dilated VUR or bilateral VUR could not benefit from antibiotic prophylaxis for cystography. What is Known: • There is no universally accepted protocol about antibiotic administration in children undergoing cystography. • Literature data are conflicting. What is New: • Among 216 non-toilet-trained children undergoing cystography, 111 patients without vesico-ureteral reflux (VUR) and 29 patients with non-dilated VUR did not receive post-procedure antibiotics and did not develop UTIs. Out of the 76 patients who showed a dilated VUR and received post-procedure antibiotics, only 5 (6.6%) developed a UTI. • The most significant factor associated to post-cystography UTIs was the presence of dilated VUR (p = 0.005) with presence of bilateral VUR also being significant (p = 0.02).

MKRN3 Levels in Girls with Central Precocious Puberty during GnRHa Treatment: A Longitudinal Study

BACKGROUND

Recently, mutations of makorin RING finger protein 3 (MKRN3) have been identified in familial central precocious puberty (CPP). Serum levels of this protein decline before the pubertal onset in healthy girls and boys and are lower in patients with CPP compared to prepubertal matched pairs. The aim of our study was to investigate longitudinal changes in circulating MKRN3 levels in patients with CPP before and during GnRH analogs (GnRHa) treatment.

METHODS

We performed a longitudinal prospective study. We enrolled 15 patients with CPP aged 7.2 years (range: 2-8) with age at breast development onset < 8 years and 12 control girls matched for the time from puberty onset (mean age 11.8 ± 1.2 years). Serum values of MKRN3, gonadotropins, and 17β-estradiol were evaluated before and during treatment with GnRHa (at 6 and 12 months). The MKRN3 gene was genotyped in CPP patients. In the girls from the control group, only basal levels were analyzed.

RESULTS

No MKRN3 mutations were found among CPP patients. MKRN3 levels declined significantly from baseline to 6 months of GnRHa treatment (p = 0.0007) and from 6 to 12 months of treatment (p = 0.003); MKRN3 levels at 6 months were significantly lower than in the control girls (p < 0.0001).

CONCLUSIONS

We showed that girls with CPP had a decline in peripheral levels of MKRN3 during GnRHa treatment. Our data suggest a suppression of MKRN3 by continuous pharmacological administration of GnRHa.

Congenital solitary kidney size at birth could predict reduced eGFR levels later in life

OBJECTIVES

To evaluate the impact of congenital solitary functioning kidney (CSFK) length, measured early in life, on the eGFR levels during the follow-up.

STUDY DESIGN

We retrospectively selected 162 CSFK patients undergoing, within 60 days of life, renal length (RL) measurement by ultrasound. We divided the population in: Group 1 = RL ≥ 2 standard deviation score (SDS). Group 2 = RL < 2 SDS and showing RL ≥ 2 SDS during the follow-up. Group 3 = RL < 2 SDS and showing RL < 2 SDS during the follow-up.

PRIMARY OUTCOME

development of eGFR below the range of normality.

RESULTS

The median follow-up period of the overall population was 6.2 years (range 2-21.5 years). The cumulative proportion of patients free of primary outcome at 15 years of age was 96.4% in group 1, 64.6% in group 2, and 45.6% in group 3 (p = 0.03). The RL > 2 SDS within 60 days of life was a significant protective factor (hazard ratio = 0.13; 95% C.I. 0.02-0.97) against development of primary outcome.

CONCLUSION

RL ≥ 2 SDS within 60 days of life could identify a population of CSFK with reduced risk of presenting reduced eGFR levels later in life.

Association between 14 bp insertion/deletion HLA-G functional polymorphism and insulin resistance in a cohort of Italian children with obesity

BACKGROUND

The non-classical HLA-class I molecule-g (HLA-G) gene shows a deletion/insertion (del/ins) polymorphism of a 14-base-pair sequence (14 bp) in the exon 8 at the 3' untranslated region. The presence of the 14 bp insertion allele has been associated to lower soluble HLA-G protein production, a protein with anti-inflammatory activities. So far, no studies have investigated the relationship between HLA-G 14 bp del/ins polymorphism and metabolic features of obese children and adolescents. We aimed to assess if the HLA-G ins/del polymorphism, and in particular the HLA-G ins/ins genotype determining lower sHLA-G production, is associated to insulin resistance (evaluated by homeostasis model assessment [HOMA]) in a population of obese children.

METHODS

We enrolled 574 obese children and adolescents. Anthropometric and laboratory data were collected. The white blood cell (WBC) count was evaluated as surrogate marker of inflammation. C-reactive protein (CRP) was available in 48 patients. HOMA was calculated. Patients were genotyped for the HLA-G del/ins polymorphism.

RESULTS

Subjects carrying the HLA-G ins/ins genotype, presented with higher HOMA, WBC and CRP values, compared to del/ins and del/del genotypes (P ≤ 0.0009, ≤0.02 and ≤0.0001, respectively). Comparison of the regression line slopes, performed for HOMA and WBC on the basis of HLA-G genotypes, showed that subjects carrying the HLA-G ins/ins genotype presented with a stronger correlation between HOMA and WBC, compared to the other genotypes (Model r² 3.13%, P ≤ 0.006).

CONCLUSIONS

We showed a strong association between HLA-G 14 bp ins/ins genotype and HOMA in obese children and adolescents. This association could be hypothetically modulated by subclinical inflammation.

Cleaning the genitalia with plain water improves accuracy of urine dipstick in childhood

We evaluated, both in toilet-trained and not-toilet-trained children, the impact of cleaning the genital area with plain water on the false positive rate at urine dipstick, and evaluated which factors could be associated to falsely positive findings. We prospectively enrolled 612 patients consecutively attending our nephro-urological outpatient clinic. Firstly, we performed urine dipsticks on urine samples collected from patients whose genital area had not been cleaned before. Then we collected a second sample from the patients with positive urine dipstick, after their genital area had been cleaned with plain water. The urine dipstick was considered falsely positive if we documented its normalization at urine dipstick made on the urine sample collected after cleaning the genital area. We found a falsely positive urine dipstick in 25.5% of the patients, and more in detail in 22.9% of the not-toilet-trained children, and in 26.6% of the toilet-trained children (p = 0.37). The only factors leading to a significant increased RR to have a false positive were non-retractable foreskin (RR = 4.38; 95% CI, 2.15-8.9; p = 0.0001) and female gender (RR = 2.47; 95% CI, 1.77-3.44; p < 0.0001).

CONCLUSION

Cleaning the genital area with plain water should always be performed before collecting urine samples, even if only a urine dipstick without culture is needed. What is Known: • Cleaning the genital area reduces the urine bacterial contamination rate in populations of toilet-trained pediatric patients. • There are no studies assessing the impact of cleaning the genital area on the quality of the urine dipstick, nor on which factors could affect the urine dipstick findings. What is New: • Falsely positive urine dipstick was found in 25.5% of the 612 prospectively enrolled toilet-trained and not-toilet-trained children. • Non-retractable foreskin and female gender significantly increases the relative risk of falsely positive urine dipsticks.

Basal levels of 17-hydroxyprogesterone can distinguish children with isolated precocious pubarche

BACKGROUND

Basal levels of androgens, in particular 17-hydroxyprogesterone (17OHP), are widely debated as predictors of non-classical congenital adrenal hyperplasia (NCCAH) among patients with precocious pubarche (PP). Many authors have recommended the use of adrenocorticotropic hormone (ACTH) stimulation test in children with PP. The aim of our study was to identify clinical and biochemical predictors of NCCAH in children with PP.

METHODS

We conducted a prospective study of 92 patients with PP undergoing an ACTH stimulation test. We tested the association of basal clinical and biochemical parameters with NCCAH diagnosis. Patients were suspected to have NCCAH if their stimulated 17OHP plasma levels were >10 ng/mL. In these patients, the diagnosis was confirmed by genetic test.

RESULTS

Seven (7.6%) patients resulted having NCCAH. The best basal biochemical predictor for NCCAH was 17OHP level >2 ng/mL. In fact, a basal 17OHP level >2 ng/mL had 100% (95% confidence interval (CI), 59.04-100) sensitivity and 93% (95% CI, 85.3-97.37) specificity. The area under the receiver-operating characteristic curve for 17OHP was 0.99 (95% CI, 0.98-1.007).

CONCLUSIONS

Basal 17OHP cut-off of 2 ng/mL was very effective in predicting NCCAH among our patients with PP. Assay-specific cut-off would probably be the best strategy to avoid unnecessary ACTH test.

Extraordinary daytime only urinary frequency in childhood: Prevalence, diagnosis, and management

INTRODUCTION

Since standardization of the ICCS terminology, only two small case series of children with extraordinary daytime only urinary frequency (EDOUF) have been published. The aims of the present study were i) to describe a large cohort of children affected by EDOUF, to evaluate its rate among the main micturition pediatric disturbances, and to determine if there is different EDOUF onset among seasons; ii) to investigate possible associations with urodynamic abnormalities by non-invasive techniques; iii) to evaluate whether postponing micturition exercise (PME) can objectively verify the anamnestic data hinting at the EDOUF diagnosis; and iv) to determine the effect of postponing micturition at home.

MATERIAL AND METHODS

We reviewed the records of all patients with EDOUF, nocturnal enuresis, and/or overactive bladder firstly examined from March 2012 to February 2016. We evaluated post-void residual and bladder wall thickness by urinary ultrasound and uroflowmetry and recorded the season in which the EDOUF started. Through the PME, the EDOUF diagnosis was confirmed if patients were able to postpone micturition reaching at least 80% of the expected bladder capacity without showing urinary incontinence. At home, we recommended postponing micturition for a maximum of 3 h if EDOUF affected the normal daily activities of both children and parents. We set a telephone interview for 3 months later.

RESULTS

The clinical characteristics of the EDOUF population are shown in the Table. The EDOUF rate was 12.1%. The rate of EDOUF onset was significantly lower during the summer than in other seasons (p = 0.02) and the OR for onset of EDOUF in the summer - compared with the other seasons - was 0.37 (95% CI 0.18-0.74; p = 0.005). Eighty-five (80.2%) patients reported an intermittent trend of the EDOUF with variable periods of improvement and worsening. All the EDOUF patients had normal uroflowmetry, 1/106 had post-micturition bladder wall thickness >5 mm and one post-void residual. At the PME, 106 out of 106 (100%) patients with EDOUF were able to reach at least 80% of the EBC without showing urinary incontinence or urgency incontinence. After 3 months, in 98.1% of the patients the symptoms had disappeared or improved.

DISCUSSION AND CONCLUSIONS

Childhood EDOUF is rather common and is generally associated with normal non-invasive urodynamic patterns. The PME allows verification of anamnestic data of EDOUF. The sole recommendation to postpone micturition for a maximum of 3 h or until the micturition postponement became stressful could be considered as a possible approach.

Anthropometric and Biochemical Determinants of Estimated Glomerular Filtration Rate in a Large Cohort of Obese Children

OBJECTIVE

We aimed to investigate which clinical and metabolic factors could influence the estimated glomerular filtration rate (eGFR) levels, evaluating a large population of obese children without suspect of primary kidney disease.

DESIGN

Retrospective, cross-sectional study.

SETTING

Pediatric university department.

SUBJECTS

We enrolled 2,957 obese children and adolescents consecutively attending our department between January 2000 and 2017. Inclusion criteria were body mass index (BMI) > 95th percentile and eGFR > 90 mL/min/1.73 m². Exclusion criteria were secondary forms of obesity, eGFR < 90 mL/min/1.73 m², proteinuria/hematuria at urine dipstick, or consumption of any medication.

INTERVENTIONS

Weight, waist circumference, height, waist to height ratio (W/Hr), BMI-standard deviation score (SDS), pubertal stage, systolic blood pressure (SBP) and diastolic blood pressure (DBP), duration of obesity, insulin, eGFR, and homeostasis model assessment (HOMA-IR) were obtained. A general linear model was performed for a multiple variable analysis.

MAIN OUTCOME MEASURE

The population was divided in tertiles for BMI-SDS, W/Hr, SBP- and DBP-SDS, HOMA-IR, and duration of obesity. We compared eGFR levels among these tertiles.

RESULTS

The eGFR levels significantly increased across both BMI-SDS and W/Hr tertiles. Conversely the eGFR levels significantly decreased across SBP-SDS, HOMA-IR, and duration of obesity tertiles. No significant differences in eGFR levels across DBP-SDS tertiles were detected. Pubertal patients presented significantly lower eGFR values compared with prepubertal patients. A general linear model for eGFR variance including as covariates W/Hr, HOMA-IR, duration of obesity, pubertal stage, BMI-SDS, and SBP-SDS (model R² 39.7%; model P < .00001) was performed. It confirmed a direct association of eGFR values with BMI-SDS and an indirect association with HOMA-IR, duration of obesity, pubertal stage, and SBP-SDS.

CONCLUSIONS

We showed a positive correlation of eGFR with both BMI-SDS and a negative one with SBP-SDS, HOMA-IR, pubertal stage, and duration of obesity. The duration of obesity was the variable most significantly associated to eGFR levels.

MKRN3 levels in girls with central precocious puberty and correlation with sexual hormone levels: a pilot study

PURPOSE

Recently, mutations of makorin RING-finger protein 3 (MKRN3) have been described in familial central precocious puberty. Serum levels of this protein decline before the pubertal onset in healthy girls and boys. The aim of the study is to investigate MKRN3 circulating levels in patients with central precocious puberty.

METHODS

We performed an observational cross-sectional study. We enrolled 17 patients with central precocious puberty aged 7 years (range: 2-8 years) and breast development onset <8 years; 17 prepubertal control age-matched patients aged 6.3 years (2-8.2); and 10 pubertal stage-matched control patients aged 11.4 years (9-14). Serum values of MKRN3, gonadotropins, (17)estradiol and Anti-Müllerian Hormone were evaluated and the MKRN3 genotyped in central precocious puberty patients.

RESULTS

No MKRN3 mutation was found among central precocious puberty patients. MKRN3 levels were lower in patients with central precocious puberty compared to prepubertal age-matched ones (p: 0.0004) and comparable to those matched for pubertal stage. MKRN3 levels were inversely correlated to Body Mass Index Standard Deviations (r:-0.35; p:0.02), Luteinizing Hormone (r:-0.35; p:0.03), FSH (r:-0.37; p:0.02), and (17)estradiol (r: -0.36; p:0.02).

CONCLUSIONS

We showed that girls with central precocious puberty had lower peripheral levels of MKRN3 compared to age-matched pairs and that they negatively correlated to gonadotropins, estrogen, and BMI. Our findings support the MKRN3 involvement in central precocious puberty also in absence of deleterious mutations, although our sample size is small. In addition our data suggest the role of MKRN3 in the complex mechanism controlling puberty onset and its interaction with other factors affecting puberty such as nutrition.

Novel association between the nonsynonymous A803G polymorphism of the N-acetyltransferase 2 gene and impaired glucose homeostasis in obese children and adolescents

BACKGROUND

The N-acetyltransferase 2 ( NAT2 ) A803G polymorphism has been associated with decreased insulin sensitivity in a large adult population with the A allele associated with insulin-resistance-related traits.

OBJECTIVE

Evaluate the association of this polymorphism with anthropometric and metabolic parameters in obese children and adolescents.

SUBJECTS

A total of 748 obese children and adolescents were enrolled.

METHODS

Anthropometric and laboratory data were collected. During oral glucose tolerance test, the presence of a possible exaggerated plasma glucose excursion at 1 h (1HPG) or impaired glucose tolerance (IGT) was considered. Homeostasis model assessment, oral disposition index (oDI) and insulinogenic index (IDI) were calculated. Patients were genotyped for the NAT2 A803G polymorphism.

RESULTS

The prevalence of both IGT and elevated-1HPG was higher in children carrying the A803 allele (P = .02 and P = .03). Moreover, this allele was associated with both oDI and IGI reduction (P = .01). No differences among the NAT2 A803G genotypes for the other parameters were shown. Children homozygous for the A allele presented an odds ratio (OR), to show IGT of 4.9 (P = .01). Children both homozygous and heterozygous for the A allele had higher risk to show elevated-1HPG (OR of 2.7, P = .005; and OR = 2.3, P = .005) compared with patients homozygous for the NAT2 803G allele.

CONCLUSIONS

NAT2 A803 allele seems to play a role in worsening the destiny of obese children carrying it, predisposing them to elevated-1HPG and IGT and then to a possible future type 2 diabetes mellitus throughout an impairment of pancreatic β-cellular insulin secretion as suggested by oDI and IGI reduction.

Multiplex Ligation-Dependent Probe Amplification Accurately Detects Turner Syndrome in Girls with Short Stature

AIMS

We aimed at evaluating a standard multiplex ligation-dependent probe amplification (MLPA) probe set for the detection of aneuploidy to diagnose Turner syndrome (TS). We first fixed an MLPA ratio cutoff able to detect all cases of TS in a pilot TS group. We then tested this value on a second group of TS patients and a short-stature population to measure specificity and sensitivity.

METHODS

15 TS patients with X mosaicism or X structural abnormalities (Pilot TS Group), 45 TS karyotype-assessed patients (TS Group), and 74 prepubertal female patients with apparent idiopathic short stature (Short-Stature Group) were enrolled. All subjects underwent MLPA and karyotype analysis. In the TS and Short-Stature Groups, MLPA testing was performed in blind.

RESULTS

The choice of an MLPA threshold ratio of 0.76 for at least 1 probe allowed us to detect all TS cases, including mosaicisms. Sensitivity and specificity were 100% (CI 95%, 0.92-1) and 88.89% (CI 95%, 0.79-0.94), respectively. The positive predictive value was 88.5%, and the negative predictive value was 100%. MLPA detected the presence of Y chromosome material in 2 patients.

CONCLUSION

MLPA is an accurate and inexpensive tool to screen for TS in girls with short stature. A customized MLPA kit may be useful for the screening of an even larger population.

Why we need a higher suspicion index of urolithiasis in children

BACKGROUND

Most children with symptoms of urolithiasis and urinary solute excretion abnormalities leading to stone formation have no calculi revealed by ultrasound or X-ray plain film ("occult urolithiasis"). This covers a large group of children presenting with common symptoms such as abdominal pain, hematuria, and dysuria, often faced by general practitioners and pediatricians. However, half or more of children with urolithiasis could present with abdominal/flank pain without specific urinary symptoms.

STUDY DESIGN

We review the current evidence about prevalence, clinical presentation, and radiological detection of overt and "occult" urolithiasis in children, aiming to give readers the instruments to suspect and diagnose urolithiasis while avoiding cost-ineffective and undue diagnostic procedures.

CONCLUSIONS

It is important to investigate for urolithiasis first by ultrasound and, in specific cases, by urinary metabolic and different imaging studies in the following groups: 1) in children with non-glomerular hematuria or/and dysuria not presenting inflammation of external genitalia; 2) in children with acute/sub-acute or infrequent recurrent abdominal pain and family history of urolithiasis in first or second degree relatives or being at higher risk of developing stones although hematuria and dysuria are lacking; 3) in children under 8 years old, even though pain is central or diffuse to the whole abdomen; and 4) in children presenting risk factors or conditions predisposing to urolithiasis. Finally, it seems reasonable to repeat ultrasound 1-2 years later also in children with "occult" urolithiasis and high risk of developing stones to detect any (re-)appearance of calculi.

Subclinical hypothyroidism in atopic South Italian children

AIM: To verify if subclinical hypothyroidism (SCH) could be associated to atopy in children.

METHODS: Seven hundred and thirty-two Caucasian children from South Italy presenting symptoms of allergic disease were enrolled and submitted to atopy, obesity, chronic low grade inflammation, and SCH work up.

RESULTS: Four hundred and forty-five out of 705 (63.12%) children affected by allergic disease were diagnosed as atopic and 260 (36.88%) as not atopic. The SCH prevalence was 6.3%. Significant higher prevalence of SCH among atopic children with average (group 2) and high (group 3) low grade chronic inflammation compared to atopic children with mild (group 1) low grade chronic inflammation was present. Moreover, group 1 and group 2 presented an OR to show SCH of 2.57 (95%CI: 1.55-6.26) and 2.96 (95%CI: 1.01-8.65), respectively. Both in atopic and not atopic children we found C3 serum levels significantly higher in group 3 respect to group 2 and group 1. Noteworthy, among atopic patients, also total immunoglobulin E (IgE) serum levels, were significantly higher in group 3 compared to group 2 and group 1 children. In atopic children, C3 and total IgE serum values increased in parallel with the increase of C-reactive protein values, while in not atopic children this phenomenon was not evident.

CONCLUSION: The possibility exists that an increasing atopic inflammation contributes to SCH occurrence. So far this is the first report in literature showing an association between SCH and atopy but further studies are needed to confirm our data.

Skin disease and thyroid autoimmunity in atopic South Italian children

AIM: To verify the prevalence of thyroid autoimmunity (TA) and the possible association between atopy and TA in children affected by skin disease.

METHODS: Three hundred and twenty-four children consecutively referred due to skin disease symptoms to our Pediatric Department were enrolled. One hundred and eighty-seven were diagnosed with atopic dermatitis (AD), 95 with acute urticaria, 40 with chronic urticaria (CU), and 2 with alopecia areata (AA). According to the work-up for atopy, the children were divided into two groups: Atopics and non-atopics. TA was diagnosed by serum thyroid peroxidase autoantibodies and/or thyroglobulin autoantibodies levels more than twice normal values over a period of two months by immunoassay.

RESULTS: In all children with skin disease, a significant prevalence of TA in atopics compared with non-atopics (13.67% vs 2.67%, P = 0.0016) and a significant association between TA and atopy (OR = 5.76, 95%CI: 1.71-19.35) were observed. These findings were confirmed as significant in children with AD: TA in atopics was 11.5%, while TA in non-atopics was 2.7% (P = 0.03, OR = 4.68, 95%CI: 1.02-21.38). In addition, atopics with CU showed a significantly higher prevalence of TA (26.9%), but none of the non-atopics showed CU (P = 0.0326). On the other hand, atopics with AA showed a 100% (2 out of 2) prevalence of TA, compared with none of the non-atopics.

CONCLUSION: In children with skin disease, atopy seems to be associated with an increased risk of TA.

Very early onset of autoimmune thyroiditis in a toddler with severe hypothyroidism presentation: a case report

BACKGROUND

In infants under 3 years of age acquired primary hypothyroidism caused by autoimmune thyroiditis is very rare. Hypothyroidism can manifest with different signs and symptoms and has a wide range of presentations from subclinical hypothyroidism to overt form. We describe a child with acquired autoimmune thyroiditis during a very early period of life and with a severe hypothyroidism presentation.

CASE PRESENTATION

A 22-month-old white male patient with normal neonatal screening presented with a six-month history of asthenia and cutaneous pallor. At general clinical and biochemical exams he showed weight gain, statural growth deceleration, poor movements, sleepy expression, instability while walking, myxoedema, bradycardia, open anterior fontanelle, changes in the face habitus, macrocytic anaemia, ascites, and high CPK, creatinine and cholesterol levels. Acquired autoimmune thyroiditis was the final diagnosis. The thyroxine replacement therapy normalized all the clinical and biochemical abnormalities but at the age of 30 months his mental age showed a delay of 6 months.

CONCLUSIONS

Our case could give useful learning points: i) although the screening for congenital hypothyroidism is routinely performed, a severe hypothyroidism (for example due to autoimmune thyroiditis) can anyway occur early in life and the clinicians should consider this possibility; ii) hypothyroidism can have a misleading and multi-face clinical presentation; iii) anemia, rhabdomyolysis and high creatinine levels should always include the hypothyroidism in the differential diagnosis; iv) thyroxine replacement therapy is able to revert all the clinical manifestations related to the hypothyroidism; v) evaluating the patient's previous pictures could play an important role in resolving a diagnostic conundrum.

TM6SF2 Glu167Lys polymorphism is associated with low levels of LDL-cholesterol and increased liver injury in obese children

BACKGROUND

The Glu167Lys (E167K) transmembrane 6 superfamily member 2 (TM6SF2) variant has been associated with liver steatosis, high alanine transaminase (ALT) levels and reduced plasma levels of liver-derived triglyceride-rich lipoproteins.

OBJECTIVES

The objectives of this study were to investigate in a group of obese children the association among the 167K allele of TM6SF2 gene and ALT, cholesterol and triglycerides levels, and hepatic steatosis, and to evaluate the potential interaction between this variant and the I148M patatin like phospholipase 3 gene (PNPLA3) polymorphism on liver enzymes.

METHODS

We genotyped 1010 obese children for TM6SF2 E167K and PNPLA3 I148M polymorphisms. Anthropometrical and biochemical data were collected. Ultrasound imaging of the liver was performed.

RESULTS

The 167K allele showed an association with steatosis (P < 0.0001), higher ALT levels (P < 0.001) and lower total cholesterol (P < 0.00001), low-density lipoprotein cholesterol (P < 0.0001), triglycerides (P = 0.02) and non-high-density lipoprotein cholesterol levels (P < 0.000001). The subjects homozygous for the PNPLA3 148M allele carrying the rare variant of TM6SF2 showed an odds ratio of 12.2 (confidence interval 3.8-39.6, P = 0.000001) to present hypertransaminasaemia compared with the remaining patients.

CONCLUSION

Although the TMS6SF2 E167K variant predisposes the obese children to non-alcoholic fatty liver disease, there is an association between this variant and lower levels of cardiovascular risk factors. Overall, the data suggest differential effects of TMS6SF2 E167K variant on liver and heart health.

Acute lobar nephritis in children: Not so easy to recognize and manage

Acute lobar nephritis (ALN) is a localized non-liquefactive inflammatory renal bacterial infection, which typically involves one or more lobes. ALN is considered to be a midpoint in the spectrum of upper urinary tract infection, a spectrum ranging from uncomplicated pyelonephritis to intrarenal abscess. This condition may be difficult to recognize due to the lack of specific symptoms and laboratory findings. Therefore the disease is probably underdiagnosed. Computed tomography scanning represents the diagnostic gold standard for ALN, but magnetic resonance imagine could be considered in order to limit irradiation. The diagnosis is relevant since initial intravenous antibiotic therapy and overall length of treatment should not be shorter than 3 wk. We review the literature and analyze the ALN clinical presentation starting from four cases with the aim to give to the clinicians the elements to suspect and recognize the ALN in children.

Iron Metabolism Dysregulation and Cognitive Dysfunction in Pediatric Obesity: Is There a Connection?

Obesity and iron deficiency (ID) are two of the most common nutritional disorders in the world. In children both conditions deserve particular attention. Several studies revealed an association between obesity and iron deficiency in children and, in some cases, a reduced response to oral supplementation. The connecting mechanism, however, is not completely known. This review is focused on: (1) iron deficiency in obese children and the role of hepcidin in the connection between body fat and poor iron status; (2) iron status and consequences on health, in particular on cognitive function; (3) cognitive function and obesity; (4) suggestion of a possible link between cognitive dysfunction and ID in pediatric obesity; and implications for therapy and future research.

A case of familial central precocious puberty caused by a novel mutation in the makorin RING finger protein 3 gene

BACKGROUND

Central precocious puberty (CPP) is often familial but its genetic cause is largely unknown. Very recently, the makorin RING finger protein 3 (MKRN3) gene, located on chromosome 15 in the Prader-Willi syndrome (PWS)-associated region (15q11-q13), has been found mutated in 5 families with familial precocious puberty. The MKRN3 is a maternal imprinted gene and the phenotype is expressed only when the MKRN3 mutations are localized on the allele inherited from the father. The function of this gene is not completely known and the phenotype caused by its defect is not yet fully elucidated. We report a new MKRN3 mutation (Pro160Cysfs*14) causing familial CPP.

CASE PRESENTATION

The index case is a 7 years old girl showing Tanner stage 3 and pubic hair stage 1. Her bone age evaluated by TW2 method was 10.3 years. Her hormonal data confirmed the diagnosis of central precocious puberty. Familial medical history revealed precocious puberty in a cousin on paternal side. Paternal grandmother had menarche at the age of 9 years and 6 months and premature menopause when she was 36 years old. Genetic analysis revealed a new mutation (c477_485del; Pro160Cysfs*14) in the maternally imprinted MKRN3. Puberty onset was at 5 years in the other affected female family member. Precocious puberty was well controlled by pharmacological therapy.

CONCLUSION

We expand the number of the MKRN3 mutations associated with CPP and highlight the importance of an accurate family medical history to disclose the peculiar pattern of inheritance of this gene.