• 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.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.

• 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.

• Clinical and Experimental Pediatrics
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• v.61 no.10
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• pp.327-331
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• 2018

Purpose: The incidence of inflammatory bowel disease (IBD) is rapidly increasing, and several reports have described the renal complications of IBD. We sought to evaluate the clinical manifestations of renal complications in children with IBD in order to enable early detection and prompt treatment of the complications. Methods: We retrospectively reviewed the medical records of 456 children and adolescents aged <20 years who had been diagnosed with IBD since 2000. We analyzed patient age, sex, medication use, IBD disease activity, and clinical manifestations of renal symptoms. Results: Our study comprising 456 children with IBD included 299 boys (65.6%) and 157 girls (34.4%). The study included 346 children with Crohn disease and 110 children with ulcerative colitis. The incidence of kidney-related symptoms was 14.7%, which was significantly higher than that in normal children. We observed 26 children (38.8%) with isolated hematuria, 30 children (44.8%) with isolated proteinuria, and 11 children (16.4%) with hematuria and concomitant proteinuria. A renal biopsy was performed in 7 children. Histopathological examination revealed immunoglobulin A nephropathy in 5 children (71.4%). All children presented with mild disease and well-controlled disease activity of IBD. Conclusion: Children with IBD are more likely to show kidney-related symptoms than healthy children and adolescents are. Therefore, regular screening of urine and evaluation of renal function in such children are necessary for early detection of renal complications.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.4
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• pp.403-411
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• 1997

To elucidate the mechanism of gentamicin induced renal dysfunction, renal functions and activities of various proximal tubular transport systems were studied in gentamicin-treated rats (Fisher 344). Gentamicin nephrotoxicity was induced by injecting gentamicin sulfate subcutaneously at a dose of 100 $mg/kg{\cdot}day$ for 7 days. The gentamicin injection resulted in a marked polyuria, hyposthenuria, proteinuria, glycosuria, aminoaciduria, phosphaturia, natriuresis, and kaliuresis, characteristics of aminoglycoside nephropathy. Such renal functional changes occurred in the face of reduced GFR, thus tubular transport functions appeared to be impaired. The polyuria and hyposthenuria were partly associated with a mild osmotic diuresis, but mostly attributed to a reduction in free water reabsorption. In renal cortical brush-border membrane vesicles isolated from gentamicin-treated rats, the $Na^+$ gradient dependent transport of glucose, alanine, phosphate and succinate was significantly attenuated with no changes in $Na^+-independent$ transport and the membrane permeability to $Na^+$. These results indicate that gentamicin treatment induces a defect in free water reabsorption in the distal nephron and impairs various $Na^+-cotransport$ systems in the proximal tubular brush-border membranes, leading to polyuria, hyposthenuria, and increased urinary excretion of $Na^+$ and other solutes.

• Childhood Kidney Diseases
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• v.18 no.2
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• pp.57-63
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• 2014

A number of kidney diseases of childhood may present as isolated proteinuria or/and hematuria, without any overt signs or symptoms. Urinalysis is a simple and inexpensive test used to evaluate various renal disorders. A school urine screening (SUS) program for kidney disease was conducted in Korea in 1998. Several research reports, including case reports and systemic reviews of SUS data, claimed that early detection and confirmatory diagnosis by renal biopsy seems to be helpful for determining the prognosis and intervention of progressive chronic renal disease. However, there is no global consensus as to whether screening for chronic kidney disease (CKD) should be undertaken in children and adolescents. This paper reviews the SUS for CKD in Korea, including the history and structure of the program, its assessment, related research, and associated problems.

• Korean Journal of Veterinary Research
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• v.46 no.1
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• pp.83-86
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• 2006

About 8 year-old castrated male Yorkshire terrier was presented for evaluation of dysuria, stranguria, hemtauria, and pollakiuria. On history taking, dysuria first was observed three months ago and these signs were waxed and waned. Physical examination revealed mild left perineal swelling. On routine laboratory examination, no significant findings were identified. Positive contrast urogram identified peritoneal herniation of urinary bladder. Urinalysis showed proteinuria and hematuria. Urine sediment revealed epithelial cells, white blood cells and rod-shaped bacteria. Pseudomonas aeroginosa was isolated from urine obtained through cystocentesis, and had resistance against fourteen antibiotics. Cystitis caused by P. aeruginosa concurrent with cystolithiasis and perineal hernia was diagnosed. Cystotomy, herniorrhaphy and EDTA-Tris solution lavage of bladder were performed. The patient was recovered to normal condition 2 days after treatment. Two weeks later, bacterial culture of urine was negative and any abnormality in ultrasonogram and urinalysis was not observed except calcium oxalate dihydrate crystals.

• 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)

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.1
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• pp.63-72
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• 2000

Chronic exposure to cadmium (Cd) results in an inhibition of protein endocytosis in the renal proximal tubule, leading to proteinuria. In order to gain insight into the mechanism by which Cd impairs the protein endocytosis, we investigated the effect of Cd on the acidification of renal cortical endocytotic vesicles (endosomes). The endosomal acidification was assessed by measuring the pH gradient-dependent fluorescence change, using acridine orange or FITC-dextran as a probe. In renal endosomes isolated from Cd-intoxicated rats, the $V_{max}$ of ATP-driven fluorescence quenching ($H^+-ATPase$ dependent intravesicular acidification) was significantly attenuated with no substantial changes in the apparent $K_m,$ indicating that the capacity of acidification was reduced. When endosomes from normal animals were directly exposed to free Cd in vitro, the $V_{max}$ was slightly reduced, whereas the $K_m$ was markedly increased, implying that the biochemical property of the $H^+-ATPase$ was altered by Cd. In endosomes exposed to free Cd in vitro, the rate of dissipation of the transmembrane pH gradient after $H^+-ATPase$ inhibition appeared to be significantly faster compared to that in normal endosomes, indicating that the $H^+-conductance$ of the membrane was increased by Cd. These results suggest that in long-term Cd-exposed animals, free Cd ions liberated in the proximal tubular cytoplasm by lysosomal degradation of cadmium-metallothionein complex (CdMT) may impair endosomal acidification 1) by reducing the $H^+-ATPase$ density in the endosomal membrane, 2) by suppressing the intrinsic $H^+-ATPase$ activity, and 3) possibly by increasing the membrane conductance to $H^+$ ion. Such effects of Cd could be responsible for the alterations of proximal tubular endocytotic activities, protein reabsorption and various transporter distributions observed in Cd-exposed cells and animals.

• 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.