Hematuria in children: causes and evaluation

Hematuria is the presence of blood in the urine and is classified as either gross hematuria or microscopic hematuria. There are many causes of hematuria, and the differential diagnosis depends on the presence or absence of comorbidities and whether it is glomerular or non-glomerular. When hematuria in children is symptomatic or persistent, an evaluation of the cause is essential. The causes of hematuria and basic approaches to its diagnosis are discussed in this review.

Clinical relevance of blood urea nitrogen to serum albumin ratio for predicting bacteremia in very young children with febrile urinary tract infection

Urinary tract infections (UTIs) are one of the most common bacterial infections in febrile children and a common cause of hospitalization, especially in very young children. We examined the clinical characteristics and predictive factors of concomitant bacteremia in pediatric patients with febrile UTI aged ≤24 months. Methods: This retrospective multicenter study reviewed medical data from 2,141 patients from three centers from January 2000 to December 2019. Enrolled cases were classified into the bacteremic UTI and non-bacteremic UTI groups according to the presence of blood culture pathogens. Results: Among 2,141 patients with febrile UTI, 40 (1.9%) had concomitant bacteremia. All patients in the bacterial group were aged ≤6 months. Multivariate analysis revealed that younger age, lower blood lymphocyte counts and serum albumin levels, higher C-reactive protein (CRP) levels, blood urea nitrogen (BUN) levels, and BUN/serum albumin ratio were independent risk factors of concomitant bacteremia. The area under the receiver-operating characteristic curves predicting bacteremia were 0.668 for CRP, 0.673 for lymphocytes, and 0.759 for the BUN/albumin ratio. Conclusion: The present study identified the BUN/albumin ratio and lower blood lymphocyte counts as novel predictive factors for bacteremia in young infants with febrile UTI in addition to the previously identified factors of younger age and higher CRP levels. Our findings could help to identify patients at high risk of bacteremia and benefit decision-making in the management of infants with febrile UTI.

Efficacy and safety of losartan in childhood immunoglobulin A nephropathy: a prospective multicenter study

Purpose@#Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) are frequently employed to counteract the detrimental effects of proteinuria on glomerular diseases. However, the effects of ARBs remain poorly examined in pediatric patients with immunoglobulin A (IgA) nephropathy. Herein, we evaluated the efficacy and safety of losartan, an ARB, in pediatric IgA nephropathy with proteinuria. @*Methods@#This prospective, single-arm, multicenter study included children with IgA nephropathy exhibiting proteinuria. Changes in proteinuria, blood pressure, and kidney function were prospectively evaluated before and 4 and 24 weeks after losartan administration. The primary endpoint was the difference in proteinuria between baseline and 24 weeks. @*Results@#In total, 29 patients were enrolled and received losartan treatment. The full analysis set included 28 patients who received losartan at least once and had pre- and post-urinary protein to creatinine ratio measurements (n=28). The per-protocol analysis group included 22 patients who completed all scheduled visits without any serious violations during the study period. In both groups, the mean log (urine protein to creatinine ratio) value decreased significantly at 6 months. After 24 weeks, the urinary protein to creatinine ratio decreased by more than 50% in approximately 40% of the patients. The glomerular filtration rate was not significantly altered during the observation period. @*Conclusions@#Losartan decreased proteinuria without decreasing kidney function in patients with IgA nephropathy over 24 weeks. Losartan could be safely employed to reduce proteinuria in this patient population. ClinicalTrials.gov trial registration (NCT0223277)

Characteristics of pediatric rhabdomyolysis and the associated risk factors for acute kidney injury: a retrospective multicenter study in Korea

Background@#The clinical features of pediatric rhabdomyolysis differ from those of the adults with rhabdomyolysis; however, multicenter studies are lacking. This study aimed to investigate the characteristics of pediatric rhabdomyolysis and reveal the risk factors for acute kidney injury (AKI) in such cases. @*Methods@#This retrospective study analyzed the medical records of children and adolescents diagnosed with rhabdomyolysis at 23 hospitals in South Korea between January 2007 and December 2016. @*Results@#Among 880 patients, those aged 3 to 5 years old composed the largest subgroup (19.4%), and all age subgroups were predominantly male. The incidence of AKI was 11.3%. Neurological disorders (53%) and infection (44%) were the most common underlying disorder and cause of rhabdomyolysis, respectively. The median age at diagnosis in the AKI subgroup was older than that in the non-AKI subgroup (12.2 years vs. 8.0 years). There were no significant differences in body mass index, myalgia, dark-colored urine, or the number of causal factors between the two AKI-status subgroups. The multivariate logistic regression model indicated that the following factors were independently associated with AKI: multiorgan failure, presence of an underlying disorder, strong positive urine occult blood, increased aspartate aminotransferase and uric acid levels, and reduced calcium levels. @*Conclusions@#Our study revealed characteristic clinical and laboratory features of rhabdomyolysis in a Korean pediatric population and highlighted the risk factors for AKI in these cases. Our findings will contribute to a greater understanding of pediatric rhabdomyolysis and may enable early intervention against rhabdomyolysis-induced AKI.

Early Onset Type 2 Diabetes Mellitus in Non-Obese Adolescents Born Small for Gestational Age

Being born small for gestational age (SGA) has been strongly associated with mortality during the perinatal period and long-term risk of metabolic syndrome, including type 2 diabetes mellitus, hypertension, hyperlipidemia, and coronary heart disease. Insulin resistance is an important factor in the development of metabolic syndrome in SGA, with several proposed hypotheses. Here, we report two cases of non-obese adolescent patients with early onset type 2 diabetes who were born SGA. Of these, one experienced catch-up growth, while the other did not. Both had a high body fat percentage at the time of diagnosis of type 2 diabetes and were diagnosed with fatty liver and hyperlipidemia before adolescence, at the age of 7 years. Early interventions for SGA are needed for healthy catch-up growth to prevent metabolic diseases in the future.

Macrolide-refractory Mycoplasma pneumoniae pneumonia and hemophagocytic lymphohistiocytosis: case report and literature review

Mycoplasma pneumoniae causes various extra-pulmonary complications. As a rare but fatal hematological complication, hemophagocytic lymphohistiocytosis (HLH) can be observed in children with M. pneumoniae infection. We report a case of a 6-year-old girl with HLH who was initially presumed to have macrolide-refractory M. pneumoniae pneumonia. Despite the combination treatment of antimicrobial and anti-inflammatory agents, she showed persistent fever, hepatosplenomegaly, and thrombocytopenia. Secondary HLH associated with M. pneumoniae should be considered if unexplained clinical deterioration is noted in children with macrolide-refractory M. pneumoniae pneumonia.

Diagnosis and Management of Chronic Kidney Disease-Mineral Bone Disease in Children

Chronic kidney disease–mineral bone disorder (CKD–MBD) is a systemic disorderof mineral and bone metabolism caused by CKD. Patients with early-stage CKDwho present with disordered regulation of bone and mineral metabolism may beasymptomatic. However, if untreated, the condition can be a significant barrierin achieving optimal bone strength, linear growth, and cardiovascular health inpediatric patients with CKD. Thus, the current study evaluated the definition, pathogenesis,diagnosis, and management of pediatric CKD-MBD.

Early Onset Type 2 Diabetes Mellitus in Non-Obese Adolescents Born Small for Gestational Age

Being born small for gestational age (SGA) has been strongly associated with mortality during the perinatal period and long-term risk of metabolic syndrome, including type 2 diabetes mellitus, hypertension, hyperlipidemia, and coronary heart disease. Insulin resistance is an important factor in the development of metabolic syndrome in SGA, with several proposed hypotheses. Here, we report two cases of non-obese adolescent patients with early onset type 2 diabetes who were born SGA. Of these, one experienced catch-up growth, while the other did not. Both had a high body fat percentage at the time of diagnosis of type 2 diabetes and were diagnosed with fatty liver and hyperlipidemia before adolescence, at the age of 7 years. Early interventions for SGA are needed for healthy catch-up growth to prevent metabolic diseases in the future.

Macrolide-refractory Mycoplasma pneumoniae pneumonia and hemophagocytic lymphohistiocytosis: case report and literature review

Mycoplasma pneumoniae causes various extra-pulmonary complications. As a rare but fatal hematological complication, hemophagocytic lymphohistiocytosis (HLH) can be observed in children with M. pneumoniae infection. We report a case of a 6-year-old girl with HLH who was initially presumed to have macrolide-refractory M. pneumoniae pneumonia. Despite the combination treatment of antimicrobial and anti-inflammatory agents, she showed persistent fever, hepatosplenomegaly, and thrombocytopenia. Secondary HLH associated with M. pneumoniae should be considered if unexplained clinical deterioration is noted in children with macrolide-refractory M. pneumoniae pneumonia.

The associations of Urinary Neutrophil Gelatinaseassociated Lipocalin (NGAL) and Liver-type Fatty Acidbinding Protein (L-FABP) Levels with Hematuria in Children and Adolescents

PURPOSE: We sought to determine associations of urinary neutrophil gelatinase-associated lipocalin (NGAL) and liver-type fatty acid-binding protein (L-FABP), known markers of renal injury, with hematuria in children and adolescents.METHODS: A total of 112 urine samples from 72 patients aged 2 to 18 years with hematuria were enrolled in this study. Urinary concentrations of NGAL and L-FABP were measured by ELISA and compared between subjects with and without proteinuria and between subjects with and without glomerulonephritis diagnosed by renal biopsy.RESULTS: Urinary concentrations of NGAL and L-FABP/creatinine (Cr) in subjects with proteinuria were not significantly different from those in subjects without proteinuria. They were not significant different between subjects with and without glomerulonephritis either. However, both concentrations of urinary NGAL and L-FABP/Cr were positively associated with urinary protein to creatinine ratio. Their levels had a tendency to be increased when proteinuria developed at later visits in subjects with hematuria only at initial visits.CONCLUSION: Monitoring urinary NGAL and L-FABP levels in addition to conventional risk factors such as proteinuria and serum creatinine might improve the prediction of renal injury in pediatric patients with hematuria.

A Case of Smith-Magenis Syndrome with Multiple Organ Malformations

Smith-Magenis syndrome (SMS) is a genetic disease caused by microdeletion of p11.2 in chromosome 17. SMS patients have characteristic facial features and accompanying congenital malformations involving the brain, cardiovascular system, and urinary tract. Compared with the distinctive facial characteristics, organ malformations are less common. Several cases of SMS with tetralogy of Fallot have been reported in Korea, none of which were accompanied by other organ malformations. We present the first case report in Korea of an SMS patient with malformations of the brain, heart, and urinary tract.

Clinical implications of DMSA Scan in Childhood Acute Pyelonephritis

PURPOSE: This study aimed to evaluate the relationships between 99mTecnicium-dimercaptosuccinic acid (DMSA) scan findings and clinical parameters including age and fever duration. METHODS: The positive rates for abnormal DMSA scans were analyzed according to the age of patients, fever duration prior to admission, and total fever duration. DMSA scan findings were divided into 3 categories: single defect, multifocal defects, and discrepant defects. We evaluated the detection rates of vesicoureteral reflux according to DMSA scan lesions. RESULTS: Among a total 320 cases, 141 (44.1%) had abnormal DMSA scans. The infant group (0-1 year of age) had a shorter total fever duration, and a lower C-reactive protein (CRP) value and DMSA positive rate (39.8% vs. 60.6%, P=0.002) compared to children group (2-15 years of age). Patients with abnormal scans had a longer total fever duration and higher CRP compared to those with normal scans. The positivity rate of abnormal scans did not differ between the patients with a short fever duration prior to admission of ≤2 days and those with longer fever duration of ≥3 days. However, patients with longer total fever duration had a higher rate of abnormal DMSA scans (P=0.02). Among cases with a single defect, multifocal defects, and discrepant defects, vesicoureteral reflux was observed in 22.4%, 60% and 70.6% of cases, respectively (P=0.004). CONCLUSION: Although DMSA scan has limitations in early diagnosis, DMSA scan findings may aid in the prediction of the severity of systemic inflammation and detection of vesicoureteral reflux.

Clinical implications of DMSA Scan in Childhood Acute Pyelonephritis

PURPOSE: This study aimed to evaluate the relationships between 99mTecnicium-dimercaptosuccinic acid (DMSA) scan findings and clinical parameters including age and fever duration. METHODS: The positive rates for abnormal DMSA scans were analyzed according to the age of patients, fever duration prior to admission, and total fever duration. DMSA scan findings were divided into 3 categories: single defect, multifocal defects, and discrepant defects. We evaluated the detection rates of vesicoureteral reflux according to DMSA scan lesions. RESULTS: Among a total 320 cases, 141 (44.1%) had abnormal DMSA scans. The infant group (0-1 year of age) had a shorter total fever duration, and a lower C-reactive protein (CRP) value and DMSA positive rate (39.8% vs. 60.6%, P=0.002) compared to children group (2-15 years of age). Patients with abnormal scans had a longer total fever duration and higher CRP compared to those with normal scans. The positivity rate of abnormal scans did not differ between the patients with a short fever duration prior to admission of ≤2 days and those with longer fever duration of ≥3 days. However, patients with longer total fever duration had a higher rate of abnormal DMSA scans (P=0.02). Among cases with a single defect, multifocal defects, and discrepant defects, vesicoureteral reflux was observed in 22.4%, 60% and 70.6% of cases, respectively (P=0.004). CONCLUSION: Although DMSA scan has limitations in early diagnosis, DMSA scan findings may aid in the prediction of the severity of systemic inflammation and detection of vesicoureteral reflux.

The Cyclosporine-A Treatment does not have Harmful Effect on the Linear Growth of Pediatric Patients with Steroid-dependent and Steroid-resistant Nephrotic Syndrome

PURPOSE: This study was performed to evaluate the effects of cyclosporine-A (CsA) on linear growth in pediatric patients with steroid-dependent (SDNS) or resistant nephrotic syndrome (SRNS). METHODS: Thirty-five pediatric patients with SDNS or SRNS undergoing glucocorticoid (GC) and/or CsA treatment were retrospectively reviewed. Seventeen patients were treated with GC alone and 18 were treated with GC and CsA. The cumulative doses of GC and CsA were quantified (mg/kg/day). Linear growth during the follow-up period was defined as the difference in Z-score between the initial and final height according to the follow-up period (Δ height Z score/year). The associations between linear growth and clinical parameters were analyzed. RESULTS: The linear growth of patients in the two groups was not significantly different (P=0.262). The Δ height Z score/year did not show a significant correlation with the cumulative doses of CsA, but was negatively correlated with the cumulative dose of GC and positively correlated with the Z score for height at the time of diagnosis. CONCLUSION: In children with SDNS or SRNS undergoing GC therapy, added CsA treatment may not have harmful effects on linear growth.

Changes in Acute Poststreptococcal Glomerulonephritis: An Observation Study at a Single Korean Hospital Over Two Decades

PURPOSE: The incidence of acute poststreptococcal glomerulonephritis (APSGN) in Korea has changed. This study aimed to evaluate the epidemiological and clinical changes of APSGN observed in a single Korean institution over two decades. METHODS: We retrospectively analyzed the data of 99 children (0-15 years of age) who were admitted to our institution with APSGN between 1987 and 2013. The patients were selected based on the depression of serum complement 3 (C3, 250 IU/dL) as evidence of previous streptococcal infection. RESULTS: In the 99 patients, the mean age was 8.3 +/- 2.7 years, and the male-tofemale ratio was 2.2:1 (66:30). The annual number of cases fluctuated markedly, and most cases were observed during the late autumn and winter months. However, there have been few cases reported in the past 5 years. Clinical manifestations at presentation, including hypertension and generalized oedema, and the duration of hospitalization were higher and longer in patients admitted during the first half of the study period than during the most recent half-period, suggesting a more severe clinical course in the former group. CONCLUSIONS: APSGN has become a rare disease in Korea with a trend towards a less severe clinical course. This finding suggests that the prevalence of infection-related immune-mediated diseases could change over-time, together with environmental and possibly pathogen-host relationship changes.

Congenital Syphilis: An Uncommon Cause of Gross Hematuria, Skin Rash, and Pneumonia / 소아감염

Although congenital syphilis can be prevented with prenatal screening, the disease remains problematic. Currently, there are no cases that describe hematuria and pneumonia related to congenital syphilis. We report a case of congenital syphilis that involved nephrotic syndrome and pneumonia alba in a 22-day-old male infant whose mother did not receive adequate prenatal care. The congenital syphilis diagnosis was confirmed with a serologic test and the patient recovered with penicillin treatment. Clinical findings may be subtle in neonates and delayed recognition occurs frequently, thus complete prenatal screening is critical for congenital syphilis prevention. Immediate serologic testing should be performed to obtain a differential diagnosis if an infant is delivered by a mother that has not received appropriate prenatal examinations.

Long-term Follow-up of Metaphyseal Sclerotic Lines in Children Treated with Pamidronate

PURPOSE: Bisphosphonates are widely used for the management steroid-induced osteoporosis (SIO) in children. With the increasing use of bisphosphonates, there have been reports of abnormal radiological findings in the growing skeleton. Therefore, their use in pediatric patients remains controversial. The present study was conducted to evaluate the long-term follow-up radiographic features, particularly metaphyseal sclerotic lines, in children who receive pamidronate therapy for nephropathy. METHODS: Twenty-four children with nephropathy treated with oral calcium and pamidronate (mean duration, 9 months; dose, 100 mg daily), were evaluated retrospectively. All patients had SIO secondary to chronic glucocorticoid therapy for treating nephropathy. Long bone radiographic imaging was performed before treatment with pamidronate, and at follow-up, several years later. Physeal growth rates were estimated by measuring the distance that the sclerotic lines moved on the radiographs during the corresponding time intervals. RESULTS: The mean follow-up period was 138 months. Long bone radiographs showed well-defined sclerotic lines at the metaphyseal ends, progressively moving from the physeal plate to the diaphysis, in all patients. The mean rate of movement of the sclerotic line was 6.21 mm per year. In 12 patients, the lines disappeared. The mean rate of growth in height was 7.33 cm per year. CONCLUSIONS: Results of long-term follow-up suggest that the metaphyseal sclerotic lines associated with pamidronate treatment tend to disappear without affecting overall skeletal growth. Bisphosphonate treatment for SIO in children with nephropathy seems to be safe, although further studies in larger number of patients are needed.

A Pediatric Case of Primary Sjogren's Syndrome Associated with Nephrogenic Diabetes Insipidus and Renal Tubular Acidosis

Sjogren's syndrome (SS) is an autoimmune disorder primarily affecting the salivary and lacrimal glands. In addition, extra-glandular manifestations involving the lungs, liver, kidneys, pancreas, skin and central nervous system were reported in patients with SS. These extra-glandular manifestations are not rare in adult patient, but are very rare in pediatric SS. Renal manifestations are relatively common in adult SS, but are rarely reported in childhood SS. We experienced a girl with primary SS manifested with nephrogenic diabetes insipidus and renal tubular acidosis.

Recent Advances of Oral Rehydration Therapy (ORT)

Diarrheal disease is one of the leading causes of worldwide morbidity and mortality, especially in children. It causes loss of body fluid, which may lead to severe dehydration, electrolyte imbalance, shock and even to death. The mortality rate from acute diarrhea has decreased over the last few decades. This decline, especially in developing countries is largely due to the implantation of the standard World Health Organization-oral rehydration solution (WHO-ORS). However, the use of standard ORS has been limited by its inability to reduce fecal volume or diarrhea duration. Subsequently, this has led to various attempts to modify its compositions. And these modifications include the use of reduced osmolarity ORS, polymer-based ORS and zinc supplementation. Some of these variations have been successful and others are still under investigation. Therefore, further trials are needed to progress toward the ideal ORS. In this article, we briefly reviewed the pathophysiologic basis of the ORS, followed by the standard WHO-ORS and several modifications to improve the ORS.

Association Study between CCL-2 and CCL-5 Polymorphisms and Clinicopathological Characteristics of Childhood IgA Nephropathy

PURPOSE: Previous studies have suggested that Chemokine (C-C motif) ligand-2 (CCL-2; also known as MCP-1) and CCL-5 (also known as RANTES) are possibly associated with the pathogenesis of various inflammatory and non-inflammatory renal diseases. The present study was conducted to investigate association of polymorphisms of CCL-2 and CCL-5 genes with childhood IgA nephropathy (IgAN). METHODS: The authors analyzed six single nucleotide polymorphisms (SNPs) of CCL-2 and CCL-5 in 196 pediatric IgAN patients and in 285 healthy controls. We compared variations in SNPs between two several sets of IgAN subgroups, allocated by presence of proteinuria (>4 mg/m2/hour), podocyte foot process effacement, and pathologically advanced disease markers, such as interstitial fibrosis, tubular atrophy, or global sclerosis. RESULTS: Genotypic data of IgAN patients and controls showed no significant SNP frequency difference in both of of CCL-2 and CCL-5. Even though two linkage disequilibrium blocks were formed, there was no significance in the haplotype analysis. In the patient subgroup analysis, no SNP of CCL-2 and CCL-5 was found to be associated with the presence of proteinuria, podocyte foot process effacement, and pathologically advanced disease markers. CONCLUSION: Our data indicate that no association exists between CCL-2 and CCL-5 SNPs and childhood IgAN susceptibility, and presence of proteinuria, podocyte foot process effacement, and pathologic progression of IgAN.