• Childhood Kidney Diseases
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• v.5 no.2
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• pp.196-205
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• 2001

Purpose : Membranous glomerulopathy is a glomerular disease characterized by the presence of subepithelial immune deposits with thickening of the capillary wall of the glomerulus without inflammatory change. The pathogenesis of membranous glomerulopathy is still unknown. Its incidence is higher in males, and it is rarely found in infants and adolescents. Among the clinical manifestations proteinuria is most common, while edema and hematuria are present. According to reports from other countries, among few patients diagnosed with membranous glomerulopathy by renal biopsy, show isolated microscopic hematuria without the clinical manifestations. Little research in this area has been performed in Korea, and so we conducted retrograde studies on membranous glomerulopathy associated with isolated microscopic hematuria. Materials and Methods : We analyzed retrogradely 109 cases of asymptomatic isolated microscopic hematuria that were diagnosed as membranous glomerulopathy by renal biopsy at Yonsei University Severance hospital from January, 1992 to July, 2001. Results : In 87 of the 109 cases patients were over 15 years old while in 22 cases patients were under 15 at the time of dignosis. Only three patients showed isolated microscopic hematuria without the clinical manifestations and abnormal laboratory findings and they were all male patients under 15 years old. Conclusion : Few cases of the membranous glomerulopathy show only asymptomatic isolated microscopic hematuria However, since membranous glomerulopathy can be found in patients who present with asymptomatic isolated microscopic hematuria only, if adequate indication for renal biopsy is present, we conclude that renal biopsy must be aggresively pursued in order to find the underlying disease. (J Korean Soc Pediatr Nephrol 2001 ; 5 : 196-205)

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.82-86
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• 2006

Purpose : The isolated microscopic hematuria is the most common abnormality detected by school urinary screening, but there is no consensus about the range of investigations and long-term outcomes of isolated hematuria in children yet. This study aims to elucidate the prognosis of hematuria and the range of diagnostic studies by follow-up results. Methods : Students with isolated hematuria who were referred to the Department of Pediatrics, Asan Medical Center from Aug. 1990 to Feb. 2004 were analysed retrospectively. Cases that presented Through significant proteinuria(>250 mg/day), other symptoms of nephritis or renal dysfunction (creatinine clearance <85 mL/min/$1.73m^2$) were excluded. Follow-up was done every six months with checking urinalysis, serum creatinine, protein and albumin. When albuminuria was detected, 24 hour urine protein was checked. Renal biopsy was done when urine protein was over 500 mg/day. Results : A total of 331 students were enrolled in this study. There were 157 males and 174 females. The mean age at presentation was $9.9{\pm}2.3$ years(7-15 years) and mean follow-up period was $2.2{\pm}1.6$ years(1-10 years). Seventy five(22.7 percent) patients showed the resolution of microscopic hematuria. The mean resolution period was $2.6{\pm}1.7$ years(1-8 years). Eight(2.4 percent) patients developed significant proteinuria and renal biopsy was done in four of them. Two cases of mild IgA nephropathy and two of minimal change were detected. None of them developed hypertension. At the end of the follow-up, renal function had remained stable in all subsets of patients. Conclusion : The prognosis of isolated microscopic hematuria was good. This study suggests that invasive studies including renal biopsy are not necessary and a regular follow-up of urinalysis is enough for children with isolated microscopic hematuria.

• Childhood Kidney Diseases
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• v.5 no.2
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• pp.156-163
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• 2001

Purpose We performed urinary mass screening(UMS) program for 2,804 children of second grade elemantary school 8 years of age in Paju city with cooperation of Paju City Health Center to determine the prevalence of asymptomatic proteinuria and hematuria, and to estimate the risk of incipient renal diseases. Also we attempted to evaluate the significance of hematuria in UMS in addidtion to proteinuria. Methods : 2,804 children of the 2nd grade of elementary school who lived in Paju city were included to our UMS program in 2000. They were constituted with 1,428 boys and 1,376 girls. The screening program was carried out in 3 steps The 1st screenig test was performed at schools and then students with abnormal results were examined repeatedly at Paju City Health Center and our hospital. Those students who showed proteinuria and/or hematuria in the 1st and 2nd test were referred to our hospital to undertake the 3rd close examination including physical examination, laboratory tests and radiologic tests. Results : (I) The prevalence of urinary abnormality in the 1st screening test was $8.3\%$(233 students), comprised of $5.9\%$ of boys, $10.8\%$ of girls. (2) Among 2,804 children tested in the first screening, prevalences of asymptomatic proteinuria and isolated hematuria were 64($2.3\%$), 163($5.8\%$) respectively, and the prevalence of proteinuria with hematuria was 6($0.2\%$). (3) Among 233 students with urinary abnormalities at the 1st screening test, 102 students applied to the 2nd test. 32 children, about one third of them, were also found to have abnormal urinary findings ; isolated hematuria 30, proteinuria with hematuria 2. (4) Those findings of clinical evaluation for children with isolated hematuria at the hospital showed as follows: idiopathic isolated microscopic hematuria 21, normal 6, urinary tract infection 1, idiopathic hypercalciuria 1 and simple renal cyst 1. Those 2 students with proteinuria and hematuria seemed to have chronic glomerulonephritis. Conclusion : (1) The clinical evaluation for children who showed positive results at the 1st screening test should be done judiciously. Because of high false positive rate, almost who showed positive results was normal, only a few of them had pathologic conditions. In this study, actual incidence of incipient renal diseases in children of 8 year old was calculated to be $0.4\%$. (2) The definite conclusion whether a urinary mass screening test can alter the prognosis of incipient renal diseases could not be drawn with this study. Further study must be necessary (3) We could acknowledge the significance of hematuria in UMS, but it is necessary that one should be judicious in managing and follow-up those that show abnormal results. (J Korean Soc Pediatr Nephrol 2001;5 : 156-63)

• Childhood Kidney Diseases
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• v.2 no.1
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• pp.34-40
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• 1998

Present study was conducted to determine the frequency, clinical characteristics and long-term outcome of children with idiopathic hypercalciuria. Study patients consisted of 150 children with isolated hematuria (recurrent gross or persistent microscopic), and hypercalciuria was defined as urinary calcium excretion over 4 mg/kg/day. During follow-up period up to $6{\sim}8$ years, serial check-up of renal sonogram for stone formation and Dipstick examination for hematuria were done. Forty-four (29%) out of 150 cases were diagnosed as idiopathic hypercalciuria, and in hypercalciuric children compared to normocalciuric children boys were more common than girls (9:35) and gross hematuria was more common than microscopic hematuria (37:7) (P<0.05). Oral calcium loading test showed renal type in 29 cases, absorptive type in 8 cases and in 7 cases type could not be definable. Among 3 types no differences could be found in 24 hour urinary calcium excretion and in clinical or laboratory data. Urolithiasis developed in 4 out of 44 cases (2 at the time of initial diagnosis and 2 within $1{\sim}2$ years of follow-up periods) and these children showed lower chronologic age ($3.7{\pm}2.7\;vs\;7.2{\pm}2.9\;yr$) and more girl than boys (3:1 vs 6:34) (P<0.05) compared to the rest of the hypercalciuric children. Follow-up urinalysis showed disappearance of hematuria in 56, 50, 66 and 75% of children at $1{\sim}2,\;2{\sim}4,\;4{\sim}6$ and $6{\sim}8$ years after initial diagnosis respectively. In conclusion, present study demonstrates that idiopathic hypercalciuria is a major cause of isolated hematuria in children so that in these children 24 hour urinary calcium excretion test seems to be an essential test to be performed. And serial renal sonography should be done to detect development of nephrolithiasis. However, clinical significance of dividing hypercalciuric children into two pathophysiologically distinct subtypes by oral calcium loading test seems to be in doubt and further study is needed to solve this problem.

• Childhood Kidney Diseases
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• v.26 no.1
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• pp.31-39
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• 2022

Alport syndrome (AS) is a progressive hereditary nephritis that is often accompanied by sensorineural hearing loss and ocular abnormalities. It is inherited in three modes of X-linked AS (XLAS), autosomal recessive AS (ARAS), and autosomal dominant AS (ADAS). XLAS is caused by pathogenic variants in COL4A5, while ARAS and ADAS are caused by those in COL4A3 or COL4A4. There is currently no curative treatment for AS; however, angiotensin-converting enzyme inhibitors (ACEi) can improve the outcome of AS. In the past decade, multiple studies have shown that early intervention with ACEi upon isolated microscopic hematuria or microalbuminuria could delay disease progression, and early diagnosis is crucial for early treatment. Therefore, a new classification of AS based on molecular diagnoses has been proposed, including the paradigm shift of re-classifying female "carriers" to "patients" and "thin basement membrane nephropathy" to "ADAS." In addition, with the detection of COL4A mutations in some patients with biopsy-confirmed IgA nephropathy, focal segmental glomerulosclerosis, and chronic kidney disease of unknown origin, it is suggested that the phenotype of AS should be expanded. In this review, we highlight the landmark studies and guidelines published over the past decade and introduce strategies for early diagnosis and treatment to improve the outcomes of AS.

• Childhood Kidney Diseases
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• v.25 no.1
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• pp.29-34
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• 2021

C3 glomerulonephritis (C3GN), a rare condition associated with dysregulation of the alternative pathway of the complement system, is histopathologically characterized by isolated or dominant C3 deposition in the renal glomeruli. We report a case of C3GN associated with anti-complement factor H (CFH) autoantibodies and CHF-related protein deficiency in an adolescent male. A 16-year-old adolescent male was admitted to a hospital with a 1-month history of generalized edema prior to presentation. Persistent microscopic hematuria and low serum C3 levels were incidentally detected at 7 and 10 years of age, respectively. Laboratory test results revealed hypoalbuminemia, nephrotic-range proteinuria, microscopic hematuria, and normal serum creatinine levels. The serum C3 and C4 levels were 17 mg/dL (normal 80-150 mg/dL) and 22 mg/mL (17-40 mg/mL), respectively. Renal biopsy showed typical features of C3GN. Further investigations revealed positive results on plasma anti-CFH autoantibody testing and a homozygous deletion of CFHR1 and CFHR3, which encode CFH-related proteins 1 and 3, respectively. Proteinuria persisted despite treatment with intravenous methylprednisolone, mycophenolate mofetil, and angiotensin-receptor blocker; however, his renal function remained stable. In conclusion, anti-CFH autoantibodies serve as important contributors to C3GN. This is the first case report that describes C3GN in an adolescent Korean male with anti-CFH autoantibodies and homozygous CFHR1 and CFHR3 deletion.

• Childhood Kidney Diseases
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• v.7 no.1
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• pp.23-29
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• 2003

Purpose : This study was performed to determine the natural history of histologically confirmed IgA nephropathy in pediatric patients who presented with hematuria and proteinuria. Patients and Methods : We reviewed the clinical course of 57 patients diagnosed with IgA nephropathy at the age of 15 years or younger from 1981 to 2000. All patients presented with hematuria or minimal proteinuria($<40\;mg/m^2/day$) and had normal renal function and blood pressure at the time of renal biopsy. Based on the clinical and pathological findings at the time of diagnosis, we sought for complications of IgA nephropathy such as heavy proteinuria(${\ge}40\;mg/m^2/day$), hypertension, and chronic renal failure. Results : The mean age at presentation was $9.5{\pm}2.8$ years(4 to 15 years) and 42(74%) were male. Isolated gross hematuria was observed in 20 patients(35%), microscopic hematuria in 3(5%), minimal proteinuria in 4(7%), both gross hematuria and minimal proteinuria in 15(26%), and both microscopic hematuria and minimal proteinuria in 15(26%). During a median follow-up of $7.0{\pm}3.5$ years, 38(67%) had complete resolution of hematuria and proteinuria, 12(21%) had persistently abnormal urinalysis without development of adverse events. Only 7(12%) developed adverse events : 4(7%) developed severe proteinuria, 1(2%) became hypertensive, and 2(3%) developed Impaired renal function. By univariate analysis using the chisquare test, the age at presentation(>10 years)(P<0.01) and poor histological classes of the Lee or Haas classification at onset(P<0.05) were significantly correlated with adverse events, whereas sex and clinical signs at onset were less concordant. Conclusion : We can conclude that the prognosis of IgA nephropathy diagnosed in early childhood is better and a good correlation exists between the clinical manifestations of this disease and the histological classes.

• Childhood Kidney Diseases
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• v.18 no.2
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• pp.128-131
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• 2014

Histopathologic evidence of "full-house" immune complex deposits is a pathognomonic feature of lupus nephritis. This report presents the case of a 12-year-old boy with persistent microscopic hematuria and proteinuria. He was diagnosed with "full-house" nephropathy based on a renal biopsy. However, there was no other clinical or biological evidence of systemic lupus erythematosus (SLE). Although the potential for isolated "full-house" nephropathy preceding SLE is unclear, such patients should be followed for clinical signs and autoantibodies of SLE. In most cases, microscopic hematuria has a good prognosis, and follow-up usually requires only regular urinalysis. However, we should be aware of isolated "full-house" nephropathy that remains asymptomatic for a long time, as few patients with no clinical signs and negative serology ultimately develop SLE.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.25-32
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• 2000

Purpose: This retrospective study of 126 children with symptomless primary hematuria was undertaken to determine the distribution of various histologic types by renal biopsy, clinical outcome according to the biopsy findings and also to find out feasibility of performing renal biopsy in these children. Patients and Methods : Study population consisted of 126 children with symptom-less primary hematuria who have been admitted to the pediatric department of Kyung-poot National University Hospital for the past 11 years from 1987 to 1998 and renal biopsy was performed percutaneously. Hematuric children with duration of less than 6 months, evidences of systemic illness such as SLE or Henoch-Schonlein purpura, urinary tract infection, and idiopathic hypercalciuria were excluded from the study. Results : Mean age of presentation was 9.2${\pm}$3.3 years (range ; 1.5-15.3 years) and male preponderance was noted with male to female ratio of 2:1. IgA nephropathy was the most common biopsy finding occuring in 60 children ($47.6\%$), followed by MsPGN in 13 ($10.3\%$), MPGN in 5 ($3.9\%$), TGBM in 6 ($4.7\%$), Alport syndrome in 2 ($1.6\%$), FSGS in 1 ($0.8\%$), and in 39 children ($30.9\%$), 'normal' glomeruli were noted. Recurrent gross hematuria was more common than persistent microscopic hematuria (84 versus 42), and especially in IgA nephropathy, recurrent gross hematuria was the most prevalent pattern of hematuria. In 58 out of 126 cases ($46.0\%$), hematuria was isolated without accompa-nying proteinuria and this was especially true In cases of MsPGN and 'normal' glomer-uli by biopsy finding. Normalization of urinalysis (disappearance of hematuria) in IgA nephropathy, MsPGN and 'normal' glomuli group were similar and it was $14\%,\;27\%\;and\;21\%$ respectively during 1-2 years of follow-up period, and $37.1\%,\;40\%\;and\;35\%$ respectively during 3-4 years of follow-up periods. However, abnormal urinalysis persi-sted in the majority of children with MPGN, TGBM. Alport syndrome and FSGS. Renal function deteriorated progressively in 6 cases (3 with IgA nephropathy, 2 with Alport syndrome and 1 with TGBM). Conclusion : In summary, present study demonstrates that in 126 children with symptomless primary hematuria, IgA nephropathy was the most common biopsy findings followed by MsPGN, MPGN, TGBM, Alport syndrome and FSGS, and 'normal glomeruli' was also seen in 39 cases ($30.9\%$). Renal histology could not be predictable on the clinical findings, so that to establish appropriate long-term planning for these children, we would recommend to obtain precise histologic diagnosis by renal biopsy.

• Childhood Kidney Diseases
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• v.25 no.2
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• pp.128-132
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• 2021

Morning glory syndrome (MGS) is a rare congenital optic disc anomaly with a characteristic fundal finding with severe visual impairment. It may occur in association with various systemic manifestations, even though most of the reported cases were isolated. A 6-year-old male visited the nephrology clinic with a history of microscopic hematuria and at the age of 12 years, he was diagnosed thin glomerular basement membrane nephropathy by kidney biopsy. After the following years, the patient had progressive deterioration of visual acuity, and diagnosed as MGS. Whole Exome Sequencing of this patient and his mother revealed heterozygous COL4A4 mutations [c.81_86del (p.Ile29_Leu30del)]. It is more reasonable to consider MGS seen in this patient as a coincidental finding of autosomal dominant Alport syndrome. To our knowledge, this case represents the first case report of autosomal dominant Alport syndrome associated with MGS.